Patent Application
20090291885
1. Field of the Invention
The present invention is related to the biochemical arts, in particular to therapeutic peptides and conjugates.
2. Discussion of the Related Art
Ion channels are a diverse group of molecules that permit the exchange of small inorganic ions across membranes. All cells require ion channels for function, but this is especially so for excitable cells such as those present in the nervous system and the heart. The electrical signals orchestrated by ion channels control the thinking brain, the beating heart and the contracting muscle. Ion channels play a role in regulating cell volume, and they control a wide variety of signaling processes.
The ion channel family includes Na+, K+, and Ca2+ cation and Cl− anion channels. Collectively, ion channels are distinguished as either ligand-gated or voltage-gated. Ligand-gated channels include both extracellular and intracellular ligand-gated channels. The extracellular ligand-gated channels include the nicotinic acetylcholine receptor (nAChR), the serotonin (5-hdroxytryptamine, 5-HT) receptors, the glycine and γ-butyric acid receptors (GABA) and the glutamate-activated channels including kanate, α-amino-3-hydroxy-5-methyl-4-isoxazole propionic acid (AMPA) and N-methyl-D-aspartate receptors (NMDA) receptors. (Harte and Ouzounis (2002), FEBS Lett. 514: 129-34). Intracellular ligand gated channels include those activated by cyclic nucleotides (e.g. cAMP, cGMP), Ca2+ and G-proteins. (Harte and Ouzounis (2002), FEBS Lett. 514: 129-34). The voltage-gated ion channels are categorized by their selectivity for inorganic ion species, including sodium, potassium, calcium and chloride ion channels. (Harte and Ouzounis (2002), FEBS Lett. 514: 129-34).
A unified nomenclature for classification of voltage-gated channels was recently presented. (Catterall et al. (2000), Pharmacol. Rev. 55: 573-4; Gutman et al. (2000), Pharmacol. Rev. 55, 583-6; Catterall et al. (2000) Pharmacol. Rev. 55: 579-81; Catterall et al. (2000), Pharmacol. Rev. 55: 575-8; Hofmann et al. (2000), Pharmacol. Rev. 55: 587-9; Clapham et al. (2000), Pharmacol Rev. 55: 591-6; Chandy (1991), Nature 352: 26; Goldin et al. (2000), Neuron 28: 365-8; Ertel et al. (2000), Neuron 25: 533-5).
The K+ channels constitute the largest and best characterized family of ion channels described to date. Potassium channels are subdivided into three general groups: the 6 transmembrane (6™) K+ channels, the 2™-2™/leak K+ channels and the 2™/K+ inward rectifying channels. (Tang et al. (2004), Ann. Rev. Physiol. 66, 131-159). These three groups are further subdivided into families based on sequence similarity. The voltage-gated K+ channels, including (Kv1-6, Kv8-9), EAG, KQT, and Slo (BKCa), are family members of the 6™ group. The 2™-2™ group comprises TWIK, TREK, TASK, TRAAK, and THIK, whereas the 2™/Kir group consists of Kir1-7. Two additional classes of ion channels include the inward rectifier potassium (IRK) and ATP-gated purinergic (P2X) channels. (Harte and Ouzounis (2002), FEBS Lett. 514: 129-34).
Toxin peptides produced by a variety of organisms have evolved to target ion channels. Snakes, scorpions, spiders, bees, snails and sea anemone are a few examples of organisms that produce venom that can serve as a rich source of small bioactive toxin peptides or “toxins” that potently and selectively target ion channels and receptors. In most cases, these toxin peptides have evolved as potent antagonists or inhibitors of ion channels, by binding to the channel pore and physically blocking the ion conduction pathway. In some other cases, as with some of the tarantula toxin peptides, the peptide is found to antagonize channel function by binding to a region outside the pore (e.g., the voltage sensor domain).
The toxin peptides are usually between about 20 and about 80 amino acids in length, contain 2-5 disulfide linkages and form a very compact structure (see, e.g.,
Conserved disulfide structures can also reflect the individual pharmacological activity of the toxin family. (Nicke et al. (2004), Eur. J. Biochem. 271: 2305-19, Table 1; Adams (1999), Drug Develop. Res. 46: 219-34). For example, α-conotoxins have well-defined four cysteine/two disulfide loop structures (Loughnan, 2004) and inhibit nicotinic acetylcholine receptors. In contrast, ω-conotoxins have six cysteine/three disulfide loop consensus structures (Nielsen, 2000) and block calcium channels. Structural subsets of toxins have evolved to inhibit either voltage-gated or calcium-activated potassium channels.
Due to their potent and selective blockade of specific ion channels, toxin peptides have been used for many years as tools to investigate the pharmacology of ion channels. Other than excitable cells and tissues such as those present in heart, muscle and brain, ion channels are also important to non-excitable cells such as immune cells. Accordingly, the potential therapeutic utility of toxin peptides has been considered for treating various immune disorders, in particular by inhibition of potassium channels such as Kv1.3 and IKCa1 since these channels indirectly control calcium signaling pathway in lymphocytes. [e.g., Kem et al., ShK toxin compositions and methods of use, U.S. Pat. No. 6,077,680; Lebrun et al., Neuropeptides originating in scorpion, U.S. Pat. No. 6,689,749; Beeton et al., Targeting effector memory T cells with a selective peptide inhibitor of Kv1.3 channels for therapy of autoimmune diseases, Molec. Pharmacol. 67(4):1369-81 (2005); Mouhat et al., K+ channel types targeted by synthetic OSK1, a toxin from Orthochirus scrobiculosus scorpion venom, Biochem. J. 385:95-104 (2005); Mouhat et al., Pharmacological profiling of Orthochirus scrobiculosus toxin 1 analogs with a trimmed N-terminal domain, Molec. Pharmacol. 69:354-62 (2006); Mouhat et al., OsK1 derivatives, WO 2006/002850 A2; B. S. Jensen et al. The Ca2+-activated K+ Channel of Intermediate Conductance: A Molecular Target for Novel Treatments?, Current Drug Targets 2:401-422 (2001); Rauer et al., Structure-guided Transformation of Charybdotoxin Yields an Analog That Selectively Targets Ca2+-activated over Voltage-gated K+ Channels, J. Biol. Chem. 275: 1201-1208 (2000); Castle et al., Maurotoxin: A Potent Inhibitor of Intermediate Conductance Ca2+-Activated Potassium Channels, Molecular Pharmacol. 63: 409-418 (2003); Chandy et al., K+ channels as targets for specific Immunomodulation, Trends in Pharmacol. Sciences 25: 280-289 (2004); Lewis & Garcia, Therapeutic Potential of Venom Peptides, Nat. Rev. Drug Discov. 2: 790-802 (2003)].
Small molecules inhibitors of Kv1.3 and IKCa1 potassium channels and the major calcium entry channel in T cells, CRAC, have also been developed to treat immune disorders [A. Schmitz et al. (2005) Molecul. Pharmacol. 68, 1254; K. G. Chandy et al. (2004) TIPS 25, 280; H. Wulff et al. (2001) J. Biol. Chem. 276, 32040; C. Zitt et al. (2004) J. Biol. Chem. 279, 12427], but obtaining small molecules with selectivity toward some of these targets has been difficult.
Calcium mobilization in lymphocytes is known to be a critical pathway in activation of inflammatory responses [M. W. Winslow et al. (2003) Current Opinion Immunol. 15, 299]. Compared to other cells, T cells show a unique sensitivity to increased levels of intracellular calcium and ion channels both directly and indirectly control this process. Inositol triphosphate (IP3) is the natural second messenger which activates the calcium signaling pathway. IP3 is produced following ligand-induced activation of the T cell receptor (TCR) and upon binding to its intracellular receptor (a channel) causes unloading of intracellular calcium stores. The endoplasmic reticulum provides one key calcium store. Thapsigargin, an inhibitor of the sarcoplasmic-endoplasmic reticulum calcium ATPase (SERCA), also causes unloading of intracellular stores and activation of the calcium signaling pathway in lymphocytes. Therefore, thapsigargin can be used as a specific stimulus of the calcium signaling pathway in T cells. The unloading of intracellular calcium stores in T cells is known to cause activation of a calcium channel on the cell surface which allows for influx of calcium from outside the cell. This store operated calcium channel (SOCC) on T cells is referred to as “CRAC” (calcium release activated channel) and sustained influx of calcium through this channel is known to be critical for full T cell activation [S. Feske et al. (2005) J. Exp. Med. 202, 651 and N. Venkatesh et al. (2004) PNAS 101, 8969]. For many years it has been appreciated that in order to maintain continued calcium influx into T cells, the cell membrane must remain in a hyperpolarized condition through efflux of potassium ions. In T cells, potassium efflux is accomplished by the voltage-gated potassium channel Kv1.3 and the calcium-activated potassium channel IKCa1 [K. G. Chandy et al. (2004) TIPS 25, 280]. These potassium channels therefore indirectly control the calcium signaling pathway, by allowing for the necessary potassium efflux that allows for a sustained influx of calcium through CRAC.
Sustained increases in intracellular calcium activate a variety of pathways in T cells, including those leading to activation of NFAT, NF-kB and AP-1 [Quintana-A (2005) Pflugers Arch.—Eur. J. Physiol. 450, 1]. These events lead to various T cell responses including alteration of cell size and membrane organization, activation of cell surface effector molecules, cytokine production and proliferation. Several calcium sensing molecules transmit the calcium signal and orchestrate the cellular response. Calmodulin is one molecule that binds calcium, but many others have been identified (M. J. Berridge et al. (2003) Nat. Rev. Mol. Cell. Biol. 4, 517). The calcium-calmodulin dependent phosphatase calcineurin is activated upon sustained increases in intracellular calcium and dephosphorylates cytosolic NFAT. Dephosphorylated NFAT quickly translocates to the nucleus and is widely accepted as a critical transcription factor for T cell activation (F. Macian (2005) Nat. Rev. Immunol. 5, 472 and N. Venkatesh et al. (2004) PNAS 101, 8969). Inhibitors of calcineurin, such as cyclosporin A (Neoral, Sand immune) and FK506 (Tacrolimus) are a main stay for treatment of severe immune disorders such as those resulting in rejection following solid organ transplant (I. M. Gonzalez-Pinto et al. (2005) Transplant. Proc. 37, 1713 and D. R. J. Kuypers (2005) Transplant International 18, 140). Neoral has been approved for the treatment of transplant rejection, severe rheumatoid arthritis (D. E. Yocum et al. (2000) Rheumatol. 39, 156) and severe psoriasis (J. Koo (1998) British J. Dermatol. 139, 88). Preclinical and clinical data has also been provided suggesting calcineurin inhibitors may have utility in treatment of inflammatory bowel disease (IBD; Baumgart D C (2006) Am. J. Gastroenterol. March 30; Epub ahead of print), multiple sclerosis (Ann. Neurol. (1990) 27, 591) and asthma (S. Rohatagi et al. (2000) J. Clin. Pharmacol. 40, 1211). Lupus represents another disorder that may benefit from agents blocking activation of helper T cells. Despite the importance of calcineurin in regulating NFAT in T cells, calcineurin is also expressed in other tissues (e.g. kidney) and cyclosporine A & FK506 have a narrow safety margin due to mechanism based toxicity. Renal toxicity and hypertension are common side effects that have limited the promise of cyclosporine & FK506. Due to concerns regarding toxicity, calcineurin inhibitors are used mostly to treat only severe immune disease (Bissonnette-R et al. (2006) J. Am. Acad. Dermatol. 54, 472). Kv1.3 inhibitors offer a safer alternative to calcineurin inhibitors for the treatment of immune disorders. This is because Kv1.3 also operates to control the calcium signaling pathway in T cells, but does so through a distinct mechanism to that of calcineurin inhibitors, and evidence on Kv1.3 expression and function show that Kv1.3 has a more restricted role in T cell biology relative to calcineurin, which functions also in a variety of non-lymphoid cells and tissues.
Calcium mobilization in immune cells also activates production of the cytokines interleukin 2 (IL-2) and interferon gamma (IFNg) which are critical mediators of inflammation. IL-2 induces a variety of biological responses ranging from expansion and differentiation of CD4+ and CD8+ T cells, to enhancement of proliferation and antibody secretion by B cells, to activation of NK cells [S. L. Gaffen & K. D. Liu (2004) Cytokine 28, 109]. Secretion of IL-2 occurs quickly following T cell activation and T cells represent the predominant source of this cytokine. Shortly following activation, the high affinity IL-2 receptor (IL2-R) is upregulated on T cells endowing them with an ability to proliferate in response to IL-2. T cells, NK cells, B cells and professional antigen presenting cells (APCs) can all secrete IFNg upon activation. T cells represent the principle source of IFNg production in mediating adaptive immune responses, whereas natural killer (NK) cells & APCs are likely an important source during host defense against infection [K. Schroder et al. (2004) J. Leukoc. Biol. 75, 163]. IFNg, originally called macrophage-activating factor, upregulates antigen processing and presentation by monocytes, macrophages and dendritic cells. IFNg mediates a diverse array of biological activities in many cell types [U. Boehm et al. (1997) Annu. Rev. Immunol. 15, 749] including growth & differentiation, enhancement of NK cell activity and regulation of B cell immunoglobulin production and class switching.
CD40L is another cytokine expressed on activated T cells following calcium mobilization and upon binding to its receptor on B cells provides critical help allowing for B cell germinal center formation, B cell differentiation and antibody isotype switching. CD40L-mediated activation of CD40 on B cells can induce profound differentiation and clonal expansion of immunoglobulin (Ig) producing B cells [S. Quezada et al. (2004) Annu. Rev. Immunol. 22, 307]. The CD40 receptor can also be found on dendritic cells and CD40L signaling can mediate dendritic cell activation and differentiation as well. The antigen presenting capacity of B cells and dendritic cells is promoted by CD40L binding, further illustrating the broad role of this cytokine in adaptive immunity. Given the essential role of CD40 signaling to B cell biology, neutralizing antibodies to CD40L have been examined in preclinical and clinical studies for utility in treatment of systemic lupus erythematosis (SLE),—a disorder characterized by deposition of antibody complexes in tissues, inflammation and organ damage [J. Yazdany and J Davis (2004) Lupus 13, 377].
Production of toxin peptides is a complex process in venomous organisms, and is an even more complex process synthetically. Due to their conserved disulfide structures and need for efficient oxidative refolding, toxin peptides present challenges to synthesis. Although toxin peptides have been used for years as highly selective pharmacological inhibitors of ion channels, the high cost of synthesis and refolding of the toxin peptides and their short half-life in vivo have impeded the pursuit of these peptides as a therapeutic modality. Far more effort has been expended to identify small molecule inhibitors as therapeutic antagonists of ion channels, than has been given the toxin peptides themselves. One exception is the recent approval of the small ω-conotoxin MVIIA peptide (Ziconotide™) for treatment of intractable pain. The synthetic and refolding production process for Ziconotide™, however, is costly and only results in a small peptide product with a very short half-life in vivo (about 4 hours).
A cost-effective process for producing therapeutics, such as but not limited to, inhibitors of ion channels, is a desideratum provided by the present invention, which involves toxin peptides fused, or otherwise covalently conjugated to a vehicle.
The present invention relates to a composition of matter of the formula:
(X1)a—(F1)d—(X2)b—(F2)e—(X3)c (I)
and multimers thereof, wherein:
F1 and F2 are half-life extending moieties, and d and e are each independently 0 or 1, provided that at least one of d and e is 1;
X1, X2, and X3 are each independently -(L)f-P-(L)g-, and f and g are each independently 0 or 1;
P is a toxin peptide of no more than about 80 amino acid residues in length, comprising at least two intrapeptide disulfide bonds, and at least one P is an OSK1 peptide analog;
L is an optional linker (present when f=1 and/or g=1); and
a, b, and c are each independently 0 or 1, provided that at least one of a, b and c is 1.
The present invention thus concerns molecules having variations on Formula I, such as the formulae:
P-(L)g-F1 (i.e., b, c, and e equal to 0); (II)
F1-(L)g-P (i.e., a, c, and e equal to 0); (III)
P-(L)g-F1-(L)f-P or (X1)a—F1—(X2)b (i.e., c and e equal to 0); (IV)
F1-(L)f-P-(L)g-F2 (i.e., a and c equal to 0); (V)
F1-(L)f-P-(L)g-F2-(L)f-P (i.e., a equal to 0); (VI)
F1—F2-(L)f-P (i.e., a and b equal to 0); (VII)
P-(L)g-F1—F2 (i.e., b and c equal to 0); (VIII)
P-(L)g-F1—F2-(L)f-P (i.e., b equal to 0); (IX)
and any multimers of any of these, when stated conventionally with the N-terminus of the peptide(s) on the left. All of such molecules of Formulae II-IX are within the meaning of Structural Formula I. Within the meaning of Formula I, the toxin peptide (P), if more than one is present, can be independently the same or different from the OSK1 peptide analog, or any other toxin peptide(s) also present in the inventive composition, and the linker moiety ((L)f and/or (L)g), if present, can be independently the same or different from any other linker, or linkers, that may be present in the inventive composition. Conjugation of the toxin peptide(s) to the half-life extending moiety, or moieties, can be via the N-terminal and/or C-terminal of the toxin peptide, or can be intercalary as to its primary amino acid sequence, F1 being linked closer to the toxin peptide's N-terminus than is linked F2. Examples of useful half-life extending moieties (F1 or F2) include immunoglobulin Fc domain (e.g., a human immunoglobulin Fc domain, including Fc of IgG1, IgG2, IgG3 or IgG4) or a portion thereof, human serum albumin (HSA), or poly(ethylene glycol) (PEG). These and other half-life extending moieties described herein are useful, either individually or in combination. A monovalent dimeric Fc-toxin peptide fusion (as represented schematically in
The present invention also relates to a composition of matter, which includes, conjugated or unconjugated, a toxin peptide analog of ShK, OSK1, ChTx, or Maurotoxin modified from the native sequences at one or more amino acid residues, having greater Kv1.3 or IKCa1 antagonist activity, and/or target selectivity, compared to a ShK, OSK1, or Maurotoxin (MTX) peptides having a native sequence. The toxin peptide analogs comprise an amino acid sequence selected from any of the following:
SEQ ID NOS: 88, 89, 92, 148 through 200, 548 through 561, 884 through 949, or 1295 through 1300 as set forth in Table 2; or
SEQ ID NOS: 980 through 1274, 1303, or 1308 as set forth in Table 7; or any of SEQ ID NOS: 1391 through 4912, 4916, 4920 through 5006, 5009, 5010, and 5012 through 5015 as set forth in Table 7A, Table 7B, Table 7C, Table 7D, Table 7E, Table 7F, Table 7G, Table 7H, Table 7I or Table 7J.
SEQ ID NOS: 330 through 337, 341, 1301, 1302, 1304 through 1307, 1309, 1311, 1312, and 1315 through 1336 as set forth in Table 13; or
SEQ ID NOS: 36, 59, 344-346, or 1369 through 1390 as set forth in Table 14.
The present invention also relates to other toxin peptide analogs that comprise an amino acid sequence selected from, or comprise the amino acid primary sequence of, any of the following:
SEQ ID NOS: 201 through 225 as set forth in Table 3; or
SEQ ID NOS: 242 through 248 or 250 through 260 as set forth in Table 4; or
SEQ ID NOS: 261 through 275 as set forth in Table 5; or
SEQ ID NOS: 276 through 293 as set forth in Table 6; or
SEQ ID NOS: 299 through 315 as set forth in Table 8; or
SEQ ID NOS: 316 through 318 as set forth in Table 9; or
SEQ ID NO: 319 as set forth in Table 10; or
SEQ ID NO: 327 or 328 as set forth in Table 11; or
SEQ ID NOS: 330 through 337, 341, 1301, 1302, 1304 through 1307, 1309, 1311, 1312, or 1315 through 1336 as set forth in Table 13;
SEQ ID NOS: 1369 through 1390 as set forth in Table 14; or
SEQ ID NOS: 348 through 353 as set forth in Table 16; or
SEQ ID NOS: 357 through 362, 364 through 368, 370, 372 through 385, or 387 through 398 as set forth in Table 19; or
SEQ ID NOS: 399 through 408 as set forth in Table 20; or
SEQ ID NOS: 410 through 421 as set forth in Table 22; or
SEQ ID NOS: 422, 424, 426, or 428 as set forth in Table 23; or
SEQ ID NOS: 430 through 437 as set forth in Table 24; or
SEQ ID NOS: 438 through 445 as set forth in Table 25; or
SEQ ID NOS: 447, 449, 451, 453, 455, or 457 as set forth in Table 26; or
SEQ ID NOS: 470 through 482 or 484 through 493 as set forth in Table 28; or
SEQ ID NOS: 495 through 506 as set forth in Table 29; or
SEQ ID NOS: 507 through 518 as set forth in Table 30.
The present invention is also directed to a pharmaceutical composition that includes the inventive composition of matter and a pharmaceutically acceptable carrier.
The compositions of this invention can be prepared by conventional synthetic methods, recombinant DNA techniques, or any other methods of preparing peptides and fusion proteins well known in the art. Compositions of this invention that have non-peptide portions can be synthesized by conventional organic chemistry reactions, in addition to conventional peptide chemistry reactions when applicable. Thus the present invention also relates to DNAs encoding the inventive compositions and expression vectors and host cells for recombinant expression.
The primary use contemplated is as therapeutic and/or prophylactic agents. The inventive compositions incorporating the toxin peptide can have activity and/or ion channel target selectivity comparable to—or even greater than—the unconjugated peptide.
Accordingly, the present invention includes a method of treating an autoimmune disorder, which involves administering to a patient who has been diagnosed with an autoimmune disorder, such as multiple sclerosis, type 1 diabetes, psoriasis, inflammatory bowel disease (IBD, including Crohn's Disease and ulcerative colitis), contact-mediated dermatitis, rheumatoid arthritis, psoriatic arthritis, asthma, allergy, restinosis, systemic sclerosis, fibrosis, scleroderma, glomerulonephritis, Sjogren syndrome, inflammatory bone resorption, transplant rejection, graft-versus-host disease, or lupus, a therapeutically effective amount of the inventive composition of matter (preferably comprising a Kv1.3 antagonist peptide or IKCa1 antagonist peptide), whereby at least one symptom of the disorder is alleviated in the patient. In addition, the present invention also relates to the use of one or more of the inventive compositions of matter in the manufacture of a medicament for the treatment or prevention of an autoimmune disorder, such as, but not limited to, any of the above-listed autoimmune disorders, e.g. multiple sclerosis, type 1 diabetes or IBD.
The present invention is further directed to a method of preventing or mitigating a relapse of a symptom of multiple sclerosis, which method involves administering to a patient, who has previously experienced at least one symptom of multiple sclerosis, a prophylactically effective amount of the inventive composition of matter (preferably comprising a Kv1.3 antagonist peptide or IKCa1 antagonist peptide), such that the at least one symptom of multiple sclerosis is prevented from recurring or is mitigated.
Although mostly contemplated as therapeutic agents, compositions of this invention can also be useful in screening for therapeutic or diagnostic agents. For example, one can use an Fc-peptide in an assay employing anti-Fc coated plates. The half-life extending moiety, such as Fc, can make insoluble peptides soluble and thus useful in a number of assays.
Numerous additional aspects and advantages of the present invention will become apparent upon consideration of the figures and detailed description of the invention.
U.S. Nonprovisional patent application Ser. No. 11/406,454, filed Apr. 17, 2006, is hereby incorporated by reference in its entirety.
The terms used throughout this specification are defined as follows, unless otherwise limited in specific instances. As used in the specification and the appended claims, the singular forms “a”, “an”, and “the” include plural referents unless the context clearly dictates otherwise.
“Polypeptide” and “protein” are used interchangeably herein and include a molecular chain of two or more amino acids linked through peptide bonds. The terms do not refer to a specific length of the product. Thus, “peptides,” and “oligopeptides,” are included within the definition of polypeptide. The terms include post-translational modifications of the polypeptide, for example, glycosylations, acetylations, phosphorylations and the like. In addition, protein fragments, analogs, mutated or variant proteins, fusion proteins and the like are included within the meaning of polypeptide. The terms also include molecules in which one or more amino acid analogs or non-canonical or unnatural amino acids are included as can be synthesized, or expressed recombinantly using known protein engineering techniques. In addition, inventive fusion proteins can be derivatized as described herein by well-known organic chemistry techniques.
The term “fusion protein” indicates that the protein includes polypeptide components derived from more than one parental protein or polypeptide. Typically, a fusion protein is expressed from a fusion gene in which a nucleotide sequence encoding a polypeptide sequence from one protein is appended in frame with, and optionally separated by a linker from, a nucleotide sequence encoding a polypeptide sequence from a different protein. The fusion gene can then be expressed by a recombinant host cell as a single protein.
A “domain” of a protein is any portion of the entire protein, up to and including the complete protein, but typically comprising less than the complete protein. A domain can, but need not, fold independently of the rest of the protein chain and/or be correlated with a particular biological, biochemical, or structural function or location (e.g., a ligand binding domain, or a cytosolic, transmembrane or extracellular domain).
A “secreted” protein refers to those proteins capable of being directed to the ER, secretory vesicles, or the extracellular space as a result of a secretory signal peptide sequence, as well as those proteins released into the extracellular space without necessarily containing a signal sequence. If the secreted protein is released into the extracellular space, the secreted protein can undergo extracellular processing to produce a “mature” protein. Release into the extracellular space can occur by many mechanisms, including exocytosis and proteolytic cleavage.
The term “signal peptide” refers to a relatively short (3-60 amino acid residues long) peptide chain that directs the post-translational transport of a protein, e.g., its export to the extracellular space. Thus, secretory signal peptides are encompassed by “signal peptide”. Signal peptides may also be called targeting signals, signal sequences, transit peptides, or localization signals.
The term “recombinant” indicates that the material (e.g., a nucleic acid or a polypeptide) has been artificially or synthetically (i.e., non-naturally) altered by human intervention. The alteration can be performed on the material within, or removed from, its natural environment or state. For example, a “recombinant nucleic acid” is one that is made by recombining nucleic acids, e.g., during cloning, DNA shuffling or other well known molecular biological procedures. A “recombinant DNA molecule,” is comprised of segments of DNA joined together by means of such molecular biological techniques. The term “recombinant protein” or “recombinant polypeptide” as used herein refers to a protein molecule which is expressed using a recombinant DNA molecule. A “recombinant host cell” is a cell that contains and/or expresses a recombinant nucleic acid.
A “polynucleotide sequence” or “nucleotide sequence” or “nucleic acid sequence,” as used interchangeably herein, is a polymer of nucleotides, including an oligonucleotide, a DNA, and RNA, a nucleic acid, or a character string representing a nucleotide polymer, depending on context. From any specified polynucleotide sequence, either the given nucleic acid or the complementary polynucleotide sequence can be determined. Included are DNA or RNA of genomic or synthetic origin which may be single- or double-stranded, and represent the sense or antisense strand.
As used herein, the terms “nucleic acid molecule encoding,” “DNA sequence encoding,” and “DNA encoding” refer to the order or sequence of deoxyribonucleotides along a strand of deoxyribonucleic acid. The order of these deoxyribonucleotides determines the order of ribonucleotides along the mRNA chain, and also determines the order of amino acids along the polypeptide (protein) chain. The DNA sequence thus codes for the RNA sequence and for the amino acid sequence.
“Expression of a gene” or “expression of a nucleic acid” means transcription of DNA into RNA (optionally including modification of the RNA, e.g., splicing), translation of RNA into a polypeptide (possibly including subsequent post-translational modification of the polypeptide), or both transcription and translation, as indicated by the context.
The term “gene” is used broadly to refer to any nucleic acid associated with a biological function. Genes typically include coding sequences and/or the regulatory sequences required for expression of such coding sequences. The term “gene” applies to a specific genomic or recombinant sequence, as well as to a cDNA or mRNA encoded by that sequence. A “fusion gene” contains a coding region that encodes a fusion protein. Genes also include non-expressed nucleic acid segments that, for example, form recognition sequences for other proteins. Non-expressed regulatory sequences including transcriptional control elements to which regulatory proteins, such as transcription factors, bind, resulting in transcription of adjacent or nearby sequences.
As used herein the term “coding region” when used in reference to a structural gene refers to the nucleotide sequences which encode the amino acids found in the nascent polypeptide as a result of translation of an mRNA molecule. The coding region is bounded, in eukaryotes, on the 5′ side by the nucleotide triplet “ATG” which encodes the initiator methionine and on the 3′ side by one of the three triplets which specify stop codons (i.e., TAA, TAG, TGA).
Transcriptional control signals in eukaryotes comprise “promoter” and “enhancer” elements. Promoters and enhancers consist of short arrays of DNA sequences that interact specifically with cellular proteins involved in transcription (Maniatis, et al., Science 236:1237 (1987)). Promoter and enhancer elements have been isolated from a variety of eukaryotic sources including genes in yeast, insect and mammalian cells and viruses (analogous control elements, i.e., promoters, are also found in prokaryotes). The selection of a particular promoter and enhancer depends on what cell type is to be used to express the protein of interest. Some eukaryotic promoters and enhancers have a broad host range while others are functional in a limited subset of cell types (for review see Voss, et al., Trends Biochem. Sci., 11:287 (1986) and Maniatis, et al., Science 236:1237 (1987)).
The term “expression vector” as used herein refers to a recombinant DNA molecule containing a desired coding sequence and appropriate nucleic acid sequences necessary for the expression of the operably linked coding sequence in a particular host cell. Nucleic acid sequences necessary for expression in prokaryotes include a promoter, optionally an operator sequence, a ribosome binding site and possibly other sequences. Eukaryotic cells are known to utilize promoters, enhancers, and termination and polyadenylation signals. A secretory signal peptide sequence can also, optionally, be encoded by the expression vector, operably linked to the coding sequence for the inventive recombinant fusion protein, so that the expressed fusion protein can be secreted by the recombinant host cell, for more facile isolation of the fusion protein from the cell, if desired. Such techniques are well known in the art. (E.g., Goodey, Andrew R.; et al., Peptide and DNA sequences, U.S. Pat. No. 5,302,697; Weiner et al., Compositions and methods for protein secretion, U.S. Pat. No. 6,022,952 and U.S. Pat. No. 6,335,178; Uemura et al., Protein expression vector and utilization thereof, U.S. Pat. No. 7,029,909; Ruben et al., 27 human secreted proteins, US 2003/0104400 A1).
The terms “in operable combination”, “in operable order” and “operably linked” as used herein refer to the linkage of nucleic acid sequences in such a manner or orientation that a nucleic acid molecule capable of directing the transcription of a given gene and/or the synthesis of a desired protein molecule is produced. The term also refers to the linkage of amino acid sequences in such a manner so that a functional protein is produced and/or transported.
Recombinant DNA- and/or RNA-mediated protein expression techniques, or any other methods of preparing peptides or, are applicable to the making of the inventive recombinant fusion proteins. For example, the peptides can be made in transformed host cells. Briefly, a recombinant DNA molecule, or construct, coding for the peptide is prepared. Methods of preparing such DNA molecules are well known in the art. For instance, sequences encoding the peptides can be excised from DNA using suitable restriction enzymes. Any of a large number of available and well-known host cells may be used in the practice of this invention. The selection of a particular host is dependent upon a number of factors recognized by the art. These include, for example, compatibility with the chosen expression vector, toxicity of the peptides encoded by the DNA molecule, rate of transformation, ease of recovery of the peptides, expression characteristics, bio-safety and costs. A balance of these factors must be struck with the understanding that not all hosts may be equally effective for the expression of a particular DNA sequence. Within these general guidelines, useful microbial host cells in culture include bacteria (such as Escherichia coli sp.), yeast (such as Saccharomyces sp.) and other fungal cells, insect cells, plant cells, mammalian (including human) cells, e.g., CHO cells and HEK293 cells. Modifications can be made at the DNA level, as well. The peptide-encoding DNA sequence may be changed to codons more compatible with the chosen host cell. For E. coli, optimized codons are known in the art. Codons can be substituted to eliminate restriction sites or to include silent restriction sites, which may aid in processing of the DNA in the selected host cell. Next, the transformed host is cultured and purified. Host cells may be cultured under conventional fermentation conditions so that the desired compounds are expressed. Such fermentation conditions are well known in the art.
The term “half-life extending moiety” (i.e., F1 or F2 in Formula I) refers to a pharmaceutically acceptable moiety, domain, or “vehicle” covalently linked (“conjugated”) to the toxin peptide directly or via a linker, that prevents or mitigates in vivo proteolytic degradation or other activity-diminishing chemical modification of the toxin peptide, increases half-life or other pharmacokinetic properties such as but not limited to increasing the rate of absorption, reduces toxicity, improves solubility, increases biological activity and/or target selectivity of the toxin peptide with respect to a target ion channel of interest, increases manufacturability, and/or reduces immunogenicity of the toxin peptide, compared to an unconjugated form of the toxin peptide.
By “PEGylated peptide” is meant a peptide or protein having a polyethylene glycol (PEG) moiety covalently bound to an amino acid residue of the peptide itself or to a peptidyl or non-peptidyl linker (including but not limited to aromatic or aryl linkers) that is covalently bound to a residue of the peptide.
By “polyethylene glycol” or “PEG” is meant a polyalkylene glycol compound or a derivative thereof, with or without coupling agents or derivatization with coupling or activating moieties (e.g., with aldehyde, hydroxysuccinimidyl, hydrazide, thiol, triflate, tresylate, azirdine, oxirane, orthopyridyl disulphide, vinylsulfone, iodoacetamide or a maleimide moiety). In accordance with the present invention, useful PEG includes substantially linear, straight chain PEG, branched PEG, or dendritic PEG. (See, e.g., Merrill, U.S. Pat. No. 5,171,264; Harris et al., Multiarmed, monofunctional, polymer for coupling to molecules and surfaces, U.S. Pat. No. 5,932,462; Shen, N-maleimidyl polymer derivatives, U.S. Pat. No. 6,602,498).
The term “peptibody” refers to molecules of Formula I in which F1 and/or F2 is an immunoglobulin Fc domain or a portion thereof, such as a CH2 domain of an Fc, or in which the toxin peptide is inserted into a human IgG1 Fc domain loop, such that F1 and F2 are each a portion of an Fc domain with a toxin peptide inserted between them (See, e.g.,
The term “native Fc” refers to molecule or sequence comprising the sequence of a non-antigen-binding fragment resulting from digestion of whole antibody, whether in monomeric or multimeric form. The original immunoglobulin source of the native Fc is preferably of human origin and can be any of the immunoglobulins, although IgG1 or IgG2 are preferred. Native Fc's are made up of monomeric polypeptides that can be linked into dimeric or multimeric forms by covalent (i.e., disulfide bonds) and non-covalent association. The number of intermolecular disulfide bonds between monomeric subunits of native Fc molecules ranges from 1 to 4 depending on class (e.g., IgG, IgA, IgE) or subclass (e.g., IgG1, IgG2, IgG3, IgG4, IgA1, IgGA2). One example of a native Fc is a disulfide-bonded dimer resulting from papain digestion of an IgG (see Ellison et al. (1982), Nucleic Acids Res. 10: 4071-9). The term “native Fc” as used herein is generic to the monomeric, dimeric, and multimeric forms.
The term “Fc variant” refers to a molecule or sequence that is modified from a native Fc but still comprises a binding site for the salvage receptor, FcRn. Several published patent documents describe exemplary Fc variants, as well as interaction with the salvage receptor. See International Applications WO 97/34 631 (published 25 Sep. 1997; WO 96/32 478, corresponding to U.S. Pat. No. 6,096,891, issued Aug. 1, 2000, hereby incorporated by reference in its entirety; and WO 04/110 472. Thus, the term “Fc variant” includes a molecule or sequence that is humanized from a non-human native Fc. Furthermore, a native Fc comprises sites that can be removed because they provide structural features or biological activity that are not required for the fusion molecules of the present invention. Thus, the term “Fc variant” includes a molecule or sequence that lacks one or more native Fc sites or residues that affect or are involved in (1) disulfide bond formation, (2) incompatibility with a selected host cell (3) N-terminal heterogeneity upon expression in a selected host cell, (4) glycosylation, (5) interaction with complement, (6) binding to an Fc receptor other than a salvage receptor, or (7) antibody-dependent cellular cytotoxicity (ADCC). Fc variants are described in further detail hereinafter.
The term “Fc domain” encompasses native Fc and Fc variant molecules and sequences as defined above. As with Fc variants and native Fc's, the term “Fc domain” includes molecules in monomeric or multimeric form, whether digested from whole antibody or produced by other means.
The term “multimer” as applied to Fc domains or molecules comprising Fc domains refers to molecules having two or more polypeptide chains associated covalently, noncovalently, or by both covalent and non-covalent interactions. IgG molecules typically form dimers; IgM, pentamers; IgD, dimers; and IgA, monomers, dimers, trimers, or tetramers. One skilled in the art can form multimers by exploiting the sequence and resulting activity of the native Ig source of the Fc or by derivatizing (as defined below) such a native Fc.
The term “dimer” as applied to Fc domains or molecules comprising Fc domains refers to molecules having two polypeptide chains associated covalently or non-covalently. Thus, exemplary dimers within the scope of this invention are as shown in
The terms “derivatizing” and “derivative” or “derivatized” comprise processes and resulting compounds respectively in which (1) the compound has a cyclic portion; for example, cross-linking between cysteinyl residues within the compound; (2) the compound is cross-linked or has a cross-linking site; for example, the compound has a cysteinyl residue and thus forms cross-linked dimers in culture or in vivo; (3) one or more peptidyl linkage is replaced by a non-peptidyl linkage; (4) the N-terminus is replaced by —NRR1, NRC(O)R1, —NRC(O)OR1, —NRS(O)2R1, —NHC(O)NHR, a succinimide group, or substituted or unsubstituted benzyloxycarbonyl-NH—, wherein R and R1 and the ring substituents are as defined hereinafter; (5) the C-terminus is replaced by —C(O)R2 or —NR3R4 wherein R2, R3 and R4 are as defined hereinafter; and (6) compounds in which individual amino acid moieties are modified through treatment with agents capable of reacting with selected side chains or terminal residues. Derivatives are further described hereinafter.
The term “peptide” refers to molecules of 2 to about 80 amino acid residues, with molecules of about 10 to about 60 amino acid residues preferred and those of about 30 to about 50 amino acid residues most preferred. Exemplary peptides can be randomly generated by any known method, carried in a peptide library (e.g., a phage display library), or derived by digestion of proteins. In any peptide portion of the inventive compositions, for example a toxin peptide or a peptide linker moiety described herein, additional amino acids can be included on either or both of the N- or C-termini of the given sequence. Of course, these additional amino acid residues should not significantly interfere with the functional activity of the composition.
“Toxin peptides” include peptides having the same amino acid sequence of a naturally occurring pharmacologically active peptide that can be isolated from a venom, and also include modified peptide analogs (spelling used interchangeably with “analogues”) of such naturally occurring molecules.
The term “peptide analog” refers to a peptide having a sequence that differs from a peptide sequence existing in nature by at least one amino acid residue substitution, internal addition, or internal deletion of at least one amino acid, and/or amino- or carboxy-terminal end truncations, or additions). An “internal deletion” refers to absence of an amino acid from a sequence existing in nature at a position other than the N- or C-terminus. Likewise, an “internal addition” refers to presence of an amino acid in a sequence existing in nature at a position other than the N- or C-terminus. “Toxin peptide analogs”, such as, but not limited to, an OSK1 peptide analog, ShK peptide analog, or ChTx peptide analog, contain modifications of a native toxin peptide sequence of interest (e.g., amino acid residue substitutions, internal additions or insertions, internal deletions, and/or amino- or carboxy-terminal end truncations, or additions as previously described above) relative to a native toxin peptide sequence of interest, which is in the case of OSK1: GVIINVKCKISRQCLEPCKKAGMRFGKCMNGKCHCTPK (SEQ ID NO:25).
Examples of toxin peptides useful in practicing the present invention are listed in Tables 1-32. The toxin peptide (“P”, or equivalently shown as “P1” in
The term “randomized” as used to refer to peptide sequences refers to fully random sequences (e.g., selected by phage display methods) and sequences in which one or more residues of a naturally occurring molecule is replaced by an amino acid residue not appearing in that position in the naturally occurring molecule. Exemplary methods for identifying peptide sequences include phage display, E. coli display, ribosome display, yeast-based screening, RNA-peptide screening, chemical screening, rational design, protein structural analysis, and the like.
The term “pharmacologically active” means that a substance so described is determined to have activity that affects a medical parameter (e.g., blood pressure, blood cell count, cholesterol level) or disease state (e.g., cancer, autoimmune disorders). Thus, pharmacologically active peptides comprise agonistic or mimetic and antagonistic peptides as defined below.
The terms “-mimetic peptide” and “-agonist peptide” refer to a peptide having biological activity comparable to a naturally occurring toxin peptide molecule, e.g., naturally occurring ShK toxin peptide. These terms further include peptides that indirectly mimic the activity of a naturally occurring toxin peptide molecule, such as by potentiating the effects of the naturally occurring molecule.
The term “antagonist peptide” or “inhibitor peptide” refers to a peptide that blocks or in some way interferes with the biological activity of a receptor of interest, or has biological activity comparable to a known antagonist or inhibitor of a receptor of interest (such as, but not limited to, an ion channel).
The term “acidic residue” refers to amino acid residues in D- or L-form having sidechains comprising acidic groups. Exemplary acidic residues include D and E.
The term “amide residue” refers to amino acids in D- or L-form having sidechains comprising amide derivatives of acidic groups. Exemplary residues include N and Q.
The term “aromatic residue” refers to amino acid residues in D- or L-form having sidechains comprising aromatic groups. Exemplary aromatic residues include F, Y, and W.
The term “basic residue” refers to amino acid residues in D- or L-form having sidechains comprising basic groups. Exemplary basic residues include H, K, R, N-methyl-arginine, ω-aminoarginine, ω-methyl-arginine, 1-methyl-histidine, 3-methyl-histidine, and homoarginine (hR) residues.
The term “hydrophilic residue” refers to amino acid residues in D- or L-form having sidechains comprising polar groups. Exemplary hydrophilic residues include C, S, T, N, Q, D, E, K, and citrulline (Cit) residues.
The term “nonfunctional residue” refers to amino acid residues in D- or L-form having sidechains that lack acidic, basic, or aromatic groups. Exemplary nonfunctional amino acid residues include M, G, A, V, I, L and norleucine (Nle).
The term “neutral polar residue” refers to amino acid residues in D- or L-form having sidechains that lack basic, acidic, or polar groups. Exemplary neutral polar amino acid residues include A, V, L, I, P, W, M, and F.
The term “polar hydrophobic residue” refers to amino acid residues in D- or L-form having sidechains comprising polar groups. Exemplary polar hydrophobic amino acid residues include T, G, S, Y, C, Q, and N.
The term “hydrophobic residue” refers to amino acid residues in D- or L-form having sidechains that lack basic or acidic groups. Exemplary hydrophobic amino acid residues include A, V, L, I, P, W, M, F, T, G, S, Y, C, Q, and N.
In some useful embodiments of the compositions of the invention, the amino acid sequence of the toxin peptide is modified in one or more ways relative to a native toxin peptide sequence of interest, such as, but not limited to, a native ShK or OSK1 sequence, their peptide analogs, or any other toxin peptides having amino acid sequences as set for in any of Tables 1-32. The one or more useful modifications can include amino acid additions or insertions, amino acid deletions, peptide truncations, amino acid substitutions, and/or chemical derivatization of amino acid residues, accomplished by known chemical techniques. Such modifications can be, for example, for the purpose of enhanced potency, selectivity, and/or proteolytic stability, or the like. Those skilled in the art are aware of techniques for designing peptide analogs with such enhanced properties, such as alanine scanning, rational design based on alignment mediated mutagenesis using known toxin peptide sequences and/or molecular modeling. For example, ShK analogs can be designed to remove protease cleavage sites (e.g., trypsin cleavage sites at K or R residues and/or chymotrypsin cleavage sites at F, Y, or W residues) in a ShK peptide- or ShK analog-containing composition of the invention, based partially on alignment mediated mutagenesis using HmK (see, e.g.,
The term “protease” is synonymous with “peptidase”. Proteases comprise two groups of enzymes: the endopeptidases which cleave peptide bonds at points within the protein, and the exopeptidases, which remove one or more amino acids from either N- or C-terminus respectively. The term “proteinase” is also used as a synonym for endopeptidase. The four mechanistic classes of proteinases are: serine proteinases, cysteine proteinases, aspartic proteinases, and metallo-proteinases. In addition to these four mechanistic classes, there is a section of the enzyme nomenclature which is allocated for proteases of unidentified catalytic mechanism. This indicates that the catalytic mechanism has not been identified.
Cleavage subsite nomenclature is commonly adopted from a scheme created by Schechter and Berger (Schechter I. & Berger A., On the size of the active site in proteases. I. Papain, Biochemical and Biophysical Research Communication, 27:157 (1967); Schechter I. & Berger A., On the active site of proteases. 3. Mapping the active site of papain; specific inhibitor peptides of papain, Biochemical and Biophysical Research Communication, 32:898 (1968)). According to this model, amino acid residues in a substrate undergoing cleavage are designated P1, P2, P3, P4 etc. in the N-terminal direction from the cleaved bond. Likewise, the residues in the C-terminal direction are designated P1′, P2′, P3′, P4′. etc.
The skilled artisan is aware of a variety of tools for identifying protease binding or protease cleavage sites of interest. For example, the PeptideCutter software tool is available through the ExPASy (Expert Protein Analysis System) proteomics server of the Swiss Institute of Bioinformatics (SIB; www.expasy.org/tools/peptidecutter). PeptideCutter searches a protein sequence from the SWISS-PROT and/or TrEMBL databases or a user-entered protein sequence for protease cleavage sites. Single proteases and chemicals, a selection or the whole list of proteases and chemicals can be used. Different forms of output of the results are available: tables of cleavage sites either grouped alphabetically according to enzyme names or sequentially according to the amino acid number. A third option for output is a map of cleavage sites. The sequence and the cleavage sites mapped onto it are grouped in blocks, the size of which can be chosen by the user. Other tools are also known for determining protease cleavage sites. (E.g., Turk, B. et al., Determination of protease cleavage site motifs using mixture-based oriented peptide libraries, Nature Biotechnology, 19:661-667 (2001); Barrett A. et al., Handbook of proteolytic enzymes, Academic Press (1998)).
The serine proteinases include the chymotrypsin family, which includes mammalian protease enzymes such as chymotrypsin, trypsin or elastase or kallikrein. The serine proteinases exhibit different substrate specificities, which are related to amino acid substitutions in the various enzyme subsites interacting with the substrate residues. Some enzymes have an extended interaction site with the substrate whereas others have a specificity restricted to the P1 substrate residue.
Trypsin preferentially cleaves at R or K in position P1. A statistical study carried out by Keil (1992) described the negative influences of residues surrounding the Arg- and Lys-bonds (i.e. the positions P2 and P1′, respectively) during trypsin cleavage. (Keil, B., Specificity of proteolysis, Springer-Verlag Berlin-Heidelberg-New York, 335 (1992)). A proline residue in position P1′ normally exerts a strong negative influence on trypsin cleavage. Similarly, the positioning of R and K in P1′ results in an inhibition, as well as negatively charged residues in positions P2 and P1′.
Chymotrypsin preferentially cleaves at a W, Y or F in position P1 (high specificity) and to a lesser extent at L, M or H residue in position P1. (Keil, 1992). Exceptions to these rules are the following: When W is found in position P1, the cleavage is blocked when M or P are found in position P1′ at the same time. Furthermore, a proline residue in position P1′ nearly fully blocks the cleavage independent of the amino acids found in position P1. When an M residue is found in position P1, the cleavage is blocked by the presence of a Y residue in position P1′. Finally, when H is located in position P1, the presence of a D, M or W residue also blocks the cleavage.
Membrane metallo-endopeptidase (NEP; neutral endopeptidase, kidney-brush-border neutral proteinase, enkephalinase, EC 3.4.24.11) cleaves peptides at the amino side of hydrophobic amino acid residues. (Connelly, J C et al., Neutral Endopeptidase 24.11 in Human Neutrophils: Cleavage of Chemotactic Peptide, PNAS, 82(24):8737-8741 (1985)).
Thrombin preferentially cleaves at an R residue in position P1. (Keil, 1992). The natural substrate of thrombin is fibrinogen. Optimum cleavage sites are when an R residue is in position P1 and Gly is in position P2 and position P1′. Likewise, when hydrophobic amino acid residues are found in position P4 and position P3, a proline residue in position P2, an R residue in position P1, and non-acidic amino acid residues in position P1′ and position P2′. A very important residue for its natural substrate fibrinogen is a D residue in P10.
Caspases are a family of cysteine proteases bearing an active site with a conserved amino acid sequence and which cleave peptides specifically following D residues. (Eamshaw W C et al., Mammalian caspases: Structure, activation, substrates, and functions during apoptosis, Annual Review of Biochemistry, 68:383-424 (1999)).
The Arg-C proteinase preferentially cleaves at an R residue in position P1. The cleavage behavior seems to be only moderately affected by residues in position P1′. (Keil, 1992). The Asp-N endopeptidase cleaves specifically bonds with a D residue in position P1′. (Keil, 1992).
Furin is a ubiquitous subtilisin-like proprotein convertase. It is the major processing enzyme of the secretory pathway and intracellularly is localized in the trans-golgi network (van den Ouweland, A. M. W. et al. (1990) Nucl. Acids Res., 18, 664; Steiner, D. F. (1998) Curr. Opin. Chem. Biol., 2, 31-39). The minimal furin cleavage site is Arg-X-X-Arg′. However, the enzyme prefers the site Arg-X-(Lys/Arg)-Arg′. An additional arginine at the P6 position appears to enhance cleavage (Krysan, D. J. et al. (1999) J. Biol. Chem., 274, 23229-23234).
The foregoing is merely exemplary and by no means an exhaustive treatment of knowledge available to the skilled artisan concerning protease binding and/or cleavage sites that the skilled artisan may be interested in eliminating in practicing the invention.
Additional useful embodiments of the toxin peptide, e.g., the OSK1 peptide analog, can result from conservative modifications of the amino acid sequences of the peptides disclosed herein. Conservative modifications will produce peptides having functional, physical, and chemical characteristics similar to those of the parent peptide from which such modifications are made. Such conservatively modified forms of the peptides disclosed herein are also contemplated as being an embodiment of the present invention.
In contrast, substantial modifications in the functional and/or chemical characteristics of the toxin peptides may be accomplished by selecting substitutions in the amino acid sequence that differ significantly in their effect on maintaining (a) the structure of the molecular backbone in the region of the substitution, for example, as an α-helical conformation, (b) the charge or hydrophobicity of the molecule at the target site, or (c) the size of the molecule.
For example, a “conservative amino acid substitution” may involve a substitution of a native amino acid residue with a normative residue such that there is little or no effect on the polarity or charge of the amino acid residue at that position. Furthermore, any native residue in the polypeptide may also be substituted with alanine, as has been previously described for “alanine scanning mutagenesis” (see, for example, MacLennan et al., Acta Physiol. Scand. Suppl., 643:55-67 (1998); Sasaki et al., 1998, Adv. Biophys. 35:1-24 (1998), which discuss alanine scanning mutagenesis).
Desired amino acid substitutions (whether conservative or non-conservative) can be determined by those skilled in the art at the time such substitutions are desired. For example, amino acid substitutions can be used to identify important residues of the peptide sequence, or to increase or decrease the affinity of the peptide or vehicle-conjugated peptide molecules described herein.
Naturally occurring residues may be divided into classes based on common side chain properties:
1) hydrophobic: norleucine (Nor), Met, Ala, Val, Leu, Ile;
2) neutral hydrophilic: Cys, Ser, Thr, Asn, Gln;
3) acidic: Asp, Glu;
4) basic: His, Lys, Arg;
5) residues that influence chain orientation: Gly, Pro; and
6) aromatic: Trp, Tyr, Phe.
Conservative amino acid substitutions may involve exchange of a member of one of these classes with another member of the same class. Conservative amino acid substitutions may encompass non-naturally occurring amino acid residues, which are typically incorporated by chemical peptide synthesis rather than by synthesis in biological systems. These include peptidomimetics and other reversed or inverted forms of amino acid moieties.
Non-conservative substitutions may involve the exchange of a member of one of these classes for a member from another class. Such substituted residues may be introduced into regions of the human antibody that are homologous with non-human antibodies, or into the non-homologous regions of the molecule.
In making such changes, according to certain embodiments, the hydropathic index of amino acids may be considered. Each amino acid has been assigned a hydropathic index on the basis of its hydrophobicity and charge characteristics. They are: isoleucine (+4.5); valine (+4.2); leucine (+3.8); phenylalanine (+2.8); cysteine/cystine (+2.5); methionine (+1.9); alanine (+1.8); glycine (−0.4); threonine (−0.7); serine (−0.8); tryptophan (−0.9); tyrosine (−1.3); proline (−1.6); histidine (−3.2); glutamate (−3.5); glutamine (−3.5); aspartate (−3.5); asparagine (−3.5); lysine (−3.9); and arginine (−4.5).
The importance of the hydropathic amino acid index in conferring interactive biological function on a protein is understood in the art (see, for example, Kyte et al., 1982, J. MOL Biol. 157:105-131). It is known that certain amino acids may be substituted for other amino acids having a similar hydropathic index or score and still retain a similar biological activity. In making changes based upon the hydropathic index, in certain embodiments, the substitution of amino acids whose hydropathic indices are within ±2 is included. In certain embodiments, those that are within ±1 are included, and in certain embodiments, those within ±0.5 are included.
It is also understood in the art that the substitution of like amino acids can be made effectively on the basis of hydrophilicity, particularly where the biologically functional protein or peptide thereby created is intended for use in immunological embodiments, as disclosed herein. In certain embodiments, the greatest local average hydrophilicity of a protein, as governed by the hydrophilicity of its adjacent amino acids, correlates with its immunogenicity and antigenicity, i.e., with a biological property of the protein.
The following hydrophilicity values have been assigned to these amino acid residues: arginine (+3.0); lysine (+3.0); aspartate (+3.0±1); glutamate (+3.0±1); serine (+0.3); asparagine (+0.2); glutamine (+0.2); glycine (0); threonine (−0.4); proline (−0.5±1); alanine (−0.5); histidine (−0.5); cysteine (−1.0); methionine (−1.3); valine (−1.5); leucine (−1.8); isoleucine (−1.8); tyrosine (−2.3); phenylalanine (−2.5) and tryptophan (−3.4). In making changes based upon similar hydrophilicity values, in certain embodiments, the substitution of amino acids whose hydrophilicity values are within ±2 is included, in certain embodiments, those that are within ±1 are included, and in certain embodiments, those within ±0.5 are included. One may also identify epitopes from primary amino acid sequences on the basis of hydrophilicity. These regions are also referred to as “epitopic core regions.”
Examples of conservative substitutions include the substitution of one non-polar (hydrophobic) amino acid residue such as isoleucine, valine, leucine norleucine, alanine, or methionine for another, the substitution of one polar (hydrophilic) amino acid residue for another such as between arginine and lysine, between glutamine and asparagine, between glycine and serine, the substitution of one basic amino acid residue such as lysine, arginine or histidine for another, or the substitution of one acidic residue, such as aspartic acid or glutamic acid for another. The phrase “conservative amino acid substitution” also includes the use of a chemically derivatized residue in place of a non-derivatized residue, provided that such polypeptide displays the requisite biological activity. Other exemplary amino acid substitutions that can be useful in accordance with the present invention are set forth in Table 1A.
In other examples, a toxin peptide amino acid sequence, e.g., an OSK1 peptide analog sequence, modified from a naturally occurring toxin peptide amino acid sequence includes at least one amino acid residue inserted or substituted therein, relative to the amino acid sequence of the native toxin peptide sequence of interest, in which the inserted or substituted amino acid residue has a side chain comprising a nucleophilic or electrophilic reactive functional group by which the peptide is conjugated to a linker or half-life extending moiety. In accordance with the invention, useful examples of such a nucleophilic or electrophilic reactive functional group include, but are not limited to, a thiol, a primary amine, a seleno, a hydrazide, an aldehyde, a carboxylic acid, a ketone, an aminooxy, a masked (protected) aldehyde, or a masked (protected) keto functional group. Examples of amino acid residues having a side chain comprising a nucleophilic reactive functional group include, but are not limited to, a lysine residue, an α,β-diaminopropionic acid residue, an α,γ-diaminobutyric acid residue, an ornithine residue, a cysteine, a homocysteine, a glutamic acid residue, an aspartic acid residue, or a selenocysteine residue. In some embodiments, the toxin peptide amino acid sequence (or “primary sequence”) is modified at one, two, three, four, five or more amino acid residue positions, by having a residue substituted therein different from the native primary sequence (e.g., OSK1 SEQ ID NO:25) or omitted (e.g., an OSK1 peptide analog optionally lacking a residue at positions 36, 37, 36-38, 37-38, or 38).
In further describing toxin peptides herein, a one-letter abbreviation system is frequently applied to designate the identities of the twenty “canonical” amino acid residues generally incorporated into naturally occurring peptides and proteins (Table 1B). Such one-letter abbreviations are entirely interchangeable in meaning with three-letter abbreviations, or non-abbreviated amino acid names. Within the one-letter abbreviation system used herein, an uppercase letter indicates a L-amino acid, and a lower case letter indicates a D-amino acid, unless otherwise noted herein. For example, the abbreviation “R” designates L-arginine and the abbreviation “r” designates D-arginine.
An amino acid substitution in an amino acid sequence is typically designated herein with a one-letter abbreviation for the amino acid residue in a particular position, followed by the numerical amino acid position relative to the native toxin peptide sequence of interest, which is then followed by the one-letter symbol for the amino acid residue substituted in. For example, “T30D” symbolizes a substitution of a threonine residue by an aspartate residue at amino acid position 30, relative to a hypothetical native toxin peptide sequence. By way of further example, “R18hR” or “R18Cit” indicates a substitution of an arginine residue by a homoarginine or a citrulline residue, respectively, at amino acid position 18, relative to the hypothetical native toxin peptide. An amino acid position within the amino acid sequence of any particular toxin peptide (or peptide analog) described herein may differ from its position relative to the native sequence, i.e., as determined in an alignment of the N-terminal or C-terminal end of the peptide's amino acid sequence with the N-terminal or C-terminal end, as appropriate, of the native toxin peptide sequence. For example, amino acid position 1 of the sequence SCIDTIPKSRCTAFQCKHSMKYRLSFCRKTCGTC ShK(2-35); SEQ ID NO:92), a N-terminal truncation of the native ShK sequence, thus aligned with the C-terminal of native ShK(1-35) (SEQ ID NO:5), corresponds to amino acid position 2 relative to the native sequence, and amino acid position 34 of SEQ ID NO:92 corresponds to amino acid position 35 relative to the native sequence (SEQ ID NO:5).
In certain embodiments of the present invention, amino acid substitutions encompass, non-canonical amino acid residues, which include naturally rare (in peptides or proteins) amino acid residues or unnatural amino acid residues. Non-canonical amino acid residues can be incorporated into the peptide by chemical peptide synthesis rather than by synthesis in biological systems, such as recombinantly expressing cells, or alternatively the skilled artisan can employ known techniques of protein engineering that use recombinantly expressing cells. (See, e.g., Link et al., Non-canonical amino acids in protein engineering, Current Opinion in Biotechnology, 14(6):603-609 (2003)). The term “non-canonical amino acid residue” refers to amino acid residues in D- or L-form that are not among the 20 canonical amino acids generally incorporated into naturally occurring proteins, for example, β-amino acids, homoamino acids, cyclic amino acids and amino acids with derivatized side chains. Examples include (in the L-form or D-form; abbreviated as in parentheses): citrulline (Cit), homocitrulline (hCit), Nα-methylcitrulline (NMeCit), Nα-methylhomocitrulline (Nα-MeHoCit), ornithine (Orn), Nα-Methylornithine (Nα-MeOrn or NMeOrn), sarcosine (Sar), homolysine (hLys or hK), homoarginine (hArg or hR), homoglutamine (hQ), Nα-methylarginine (NMeR), Nα-methylleucine (Nα-MeL or NMeL), N-methylhomolysine (NMeHoK), Nα-methylglutamine (NMeQ), norleucine (Nle), norvaline (Nva), 1,2,3,4-tetrahydroisoquinoline (Tic), Octahydroindole-2-carboxylic acid (Oic), 3-(1-naphthyl)alanine (1-Nal), 3-(2-naphthyl)alanine (2-Nal), 1,2,3,4-tetrahydroisoquinoline (Tic), 2-indanylglycine (Igl), para-iodophenylalanine (pI-Phe), para-aminophenylalanine (4AmP or 4-Amino-Phe), 4-guanidino phenylalanine (Guf), glycyllysine (abbreviated herein “K(Nε-glycyl)” or “K(glycyl)” or “K(gly)”), nitrophenylalanine (nitrophe), aminophenylalanine (aminophe or Amino-Phe), benzylphenylalanine (benzylphe), γ-carboxyglutamic acid (γ-carboxyglu), hydroxyproline (hydroxypro), p-carboxyl-phenylalanine (Cpa), α-aminoadipic acid (Aad), Nα-methyl valine (NMeVal), N-α-methyl leucine (NMeLeu), Nα-methylnorleucine (NMeNle), cyclopentylglycine (Cpg), cyclohexylglycine (Chg), acetylarginine (acetylarg), α,β-diaminopropionoic acid (Dpr), α,γ-diaminobutyric acid (Dab), diaminopropionic acid (Dap), cyclohexylalanine (Cha), 4-methyl-phenylalanine (MePhe), β,β-diphenyl-alanine (BiPhA), aminobutyric acid (Abu), 4-phenyl-phenylalanine (or biphenylalanine; 4Bip), α-amino-isobutyric acid (Aib), beta-alanine, beta-aminopropionic acid, piperidinic acid, aminocaproic acid, aminoheptanoic acid, aminopimelic acid, desmosine, diaminopimelic acid, N-ethylglycine, N-ethylaspargine, hydroxylysine, allo-hydroxylysine, isodesmosine, allo-isoleucine, N-methylglycine, N-methylisoleucine, N-methylvaline, 4-hydroxyproline (Hyp), γ-carboxyglutamate, ε-N,N,N-trimethyllysine, ε-N-acetyllysine, O-phosphoserine, N-acetylserine, N-formylmethionine, 3-methylhistidine, 5-hydroxylysine, ω-methylarginine, 4-Amino-O-Phthalic Acid (4APA), and other similar amino acids, and derivatized forms of any of these as described herein. Table 1B contains some exemplary non-canonical amino acid residues that are useful in accordance with the present invention and associated abbreviations as typically used herein, although the skilled practitioner will understand that different abbreviations and nomenclatures may be applicable to the same substance and my appear interchangeably herein.
Table 1B. Useful non-canonical amino acids for amino acid addition, insertion, or substitution into toxin peptide sequences, including OSK1 peptide analog sequences, in accordance with the present invention. In the event an abbreviation listed in Table 1B differs from another abbreviation for the same substance disclosed elsewhere herein, both abbreviations are understood to be applicable.
Nomenclature and Symbolism for Amino Acids and Peptides by the UPAC-IUB Joint Commission on Biochemical Nomenclature (JCBN) have been published in the following documents: Biochem. J., 1984, 219, 345-373; Eur. J. Biochem., 1984, 138, 9-37; 1985, 152, 1; 1993, 213, 2; Internat. J. Pept. Prot. Res., 1984, 24, following p 84; J. Biol. Chem., 1985, 260, 14-42; Pure Appl. Chem., 1984, 56, 595-624; Amino Acids and Peptides, 1985, 16, 387-410; Biochemical Nomenclature and Related Documents, 2nd edition, Portland Press, 1992, pages 39-69].
As stated herein, in accordance with the present invention, peptide portions of the inventive compositions, such as the toxin peptide or a peptide linker, can also be chemically derivatized at one or more amino acid residues. Peptides that contain derivatized amino acid residues can be synthesized by known organic chemistry techniques. “Chemical derivative” or “chemically derivatized” in the context of a peptide refers to a subject peptide having one or more residues chemically derivatized by reaction of a functional side group. Such derivatized molecules include, for example, those molecules in which free amino groups have been derivatized to form amine hydrochlorides, p-toluene sulfonyl groups, carbobenzoxy groups, t-butyloxycarbonyl groups, chloroacetyl groups or formyl groups. Free carboxyl groups may be derivatized to form salts, methyl and ethyl esters or other types of esters or hydrazides. Free hydroxyl groups may be derivatized to form O-acyl or O-alkyl derivatives. The imidazole nitrogen of histidine may be derivatized to form N-im-benzylhistidine. Also included as chemical derivatives are those peptides which contain one or more naturally occurring amino acid derivatives of the twenty canonical amino acids, whether in L- or D-form. For example, 4-hydroxyproline may be substituted for proline; 5-hydroxylysine maybe substituted for lysine; 3-methylhistidine may be substituted for histidine; homoserine may be substituted for serine; and ornithine may be substituted for lysine.
Useful derivatizations include, in some embodiments, those in which the amino terminal of the toxin peptide, such as but not limited to the OSK1 peptide analog, is chemically blocked so that conjugation with the vehicle will be prevented from taking place at an N-terminal free amino group. There may also be other beneficial effects of such a modification, for example a reduction in the toxin peptide's susceptibility to enzymatic proteolysis. The N-terminus of the toxin peptide, e.g., the OSK1 peptide analog, can be acylated or modified to a substituted amine, or derivatized with another functional group, such as an aromatic or aryl moiety (e.g., an indole acid, benzyl (Bzl or Bn), dibenzyl (DiBzl or Bn2), benzoyl, or benzyloxycarbonyl (Cbz or Z)), N,N-dimethylglycine or creatine. For example, in some embodiments, an acyl moiety, such as, but not limited to, a formyl, acetyl (Ac), propanoyl, butanyl, heptanyl, hexanoyl, octanoyl, or nonanoyl, can be covalently linked to the N-terminal end of the peptide, e.g., the OSK1 peptide analog, which can prevent undesired side reactions during conjugation of the vehicle to the peptide. Alternatively, a fatty acid (e.g. butyric, caproic, caprylic, capric, lauric, myristic, palmitic, stearic or the like) or polyethylene glycol moiety can be covalently linked to the N-terminal end of the peptide, e.g., the OSK1 peptide analog. Other exemplary N-terminal derivative groups include —NRR1 (other than —NH2), —NRC(O)R1, —NRC(O)OR1, —NRS(O)2R1, —NHC(O)NHR1, succinimide, or benzyloxycarbonyl-NH-(Cbz-NH—), wherein R and R1 are each independently hydrogen or lower alkyl and wherein the phenyl ring may be substituted with 1 to 3 substituents selected from C1-C4 alkyl, C1-C4 alkoxy, chloro, and bromo.
In some embodiments of the present invention, basic residues (e.g., lysine) of the toxin peptide of interest can be replaced with other residues (nonfunctional residues preferred). Such molecules will be less basic than the molecules from which they are derived and otherwise retain the activity of the molecules from which they are derived, which can result in advantages in stability and immunogenicity; the present invention should not, however, be limited by this theory.
Additionally, physiologically acceptable salts of the inventive compositions are also encompassed, including when the inventive compositions are referred to herein as “molecules” or “compounds.”. By “physiologically acceptable salts” is meant any salts that are known or later discovered to be pharmaceutically acceptable. Some non-limiting examples of pharmaceutically acceptable salts are: acetate; trifluoroacetate; hydrohalides, such as hydrochloride and hydrobromide; sulfate; citrate; maleate; tartrate; glycolate; gluconate; succinate; mesylate; besylate; salts of gallic acid esters (gallic acid is also known as 3, 4, 5 trihydroxybenzoic acid) such as PentaGalloylGlucose (PGG) and epigallocatechin gallate (EGCG), salts of cholesteryl sulfate, pamoate, tannate and oxalate salts.
Structure of Compounds:
In general. Recombinant proteins have been developed as therapeutic agents through, among other means, covalent attachment to half-life extending moieties. Such moieties include the “Fc” domain of an antibody, as is used in Enbrel® (etanercept), as well as biologically suitable polymers (e.g., polyethylene glycol, or “PEG”), as is used in Neulasta® (pegfilgrastim). Feige et al. described the use of such half-life extenders with peptides in U.S. Pat. No. 6,660,843, issued Dec. 9, 2003 (hereby incorporated by reference in its entirety).
The present inventors have determined that molecules of this invention-peptides of about 80 amino acids or less with at least two intrapeptide disulfide bonds-possess therapeutic advantages when covalently attached to half-life extending moieties. Molecules of the present invention can further comprise an additional pharmacologically active, covalently bound peptide, which can be bound to the half-life extending moiety (F1 and/or F2) or to the peptide portion (P). Embodiments of the inventive compositions containing more than one half-life extending moiety (F1 and F2) include those in which F1 and F2 are the same or different half-life extending moieties. Examples (with or without a linker between each domain) include structures as illustrated in
20KPEG—toxin peptide—Fc domain, consistent with the formula [(F1)1—(X2)1—(F2)1];
20KPEG—toxin peptide—Fc CH2 domain, consistent with the formula [(F1)1—(X2)1—(F2)1];
20KPEG—toxin peptide—HSA, consistent with the formula [(F1)1(X2)1—(F2)1];
20KPEG—Fc domain—toxin peptide, consistent with the formula [(F1)1—(F2)1—(X3)1];
20KPEG—Fc CH2 domain—toxin peptide, consistent with the formula [(F1)1—(F2)1—(X3)1]; and
20KPEG—HSA—toxin peptide, consistent with the formula [(F1)1—(F2)1—(X3)1].
Toxin peptides. Any number of toxin peptides (i.e., “P”, or equivalently shown as “P1” in
In some embodiments of the invention, other peptides of interest are especially useful in molecules having additional features over the molecules of structural Formula I. In such molecules, the molecule of Formula I further comprises an additional pharmacologically active, covalently bound peptide, which is an agonistic peptide, an antagonistic peptide, or a targeting peptide; this peptide can be conjugated to F1 or F2 or P. Such agonistic peptides have activity agonistic to the toxin peptide but are not required to exert such activity by the same mechanism as the toxin peptide. Peptide antagonists are also useful in embodiments of the invention, with a preference for those with activity that can be complementary to the activity of the toxin peptide. Targeting peptides are also of interest, such as peptides that direct the molecule to particular cell types, organs, and the like. These classes of peptides can be discovered by methods described in the references cited in this specification and other references. Phage display, in particular, is useful in generating toxin peptides for use in the present invention. Affinity selection from libraries of random peptides can be used to identify peptide ligands for any site of any gene product. Dedman et al. (1993), J. Biol. Chem. 268: 23025-30. Phage display is particularly well suited for identifying peptides that bind to such proteins of interest as cell surface receptors or any proteins having linear epitopes. Wilson et al. (1998), Can. J. Microbiol. 44: 313-29; Kay et al. (1998), Drug Disc. Today 3: 370-8. Such proteins are extensively reviewed in Herz et al. (1997), J. Receptor and Signal Transduction Res. 17(5): 671-776, which is hereby incorporated by reference in its entirety. Such proteins of interest are preferred for use in this invention.
Particularly preferred peptides appear in the following tables. These peptides can be prepared by methods disclosed in the art or as described hereinafter. Single letter amino acid abbreviations are used. Unless otherwise specified, each X is independently a nonfunctional residue.
Many peptides as described in Table 2 can be prepared as described in U.S. Pat. No. 6,077,680 issued Jun. 20, 2000 to Kem et al., which is hereby incorporated by reference in its entirety. Other peptides of Table 2 can be prepared by techniques known in the art. For example, ShK(L5) (SEQ ID NO: 950) can be prepared as described in Beeton et al., Targeting effector memory T cells with a selective peptide inhibitor of Kv1.3 channels for therapy of autoimmune diseases, Molec. Pharmacol. 67(4): 1369-81 (2005), which is hereby incorporated by reference in its entirety. In Table 2 and throughout the specification, Xs15, Xs21, Xs22, Xs23 and Xs27 each independently refer to nonfunctional amino acid residues.
In Table 3 and throughout the specification, Xh6, Xh22, Xh26 are each independently nonfunctional residues.
Many peptides as described in Table 4 can be prepared as described in WO 95/03065, published Feb. 2, 1995, for which the applicant is Merck & Co., Inc. That application corresponds to U.S. Ser. No. 07/096,942, filed 22 Jul. 1993, which is hereby incorporated by reference in its entirety.
Heteromitrus spinnifer (HsTx1) peptide and HsTx1
Peptides as described in Table 5 can be prepared as described in U.S. Pat. No. 6,689,749, issued Feb. 10, 2004 to Lebrun et al., which is hereby incorporated by reference in its entirety.
Orthochirus scrobiculosus (OSK1) peptide and OSK1 peptide analog sequences
GVIINVKCKISAQCLKPCRDAGMRFGKCMNGKCACTPK
GVIINVKCKISAQCLKPCKDAGMRFGKCMNGKCHCTPK
GVIINVKCKISPQCLKPCKDAGIRFGKCINGKCACTPK
GVIINVKCKISRQCLKPCKEAGMRFGKCMNGKCACTPK
GGGGSGVIINVKCKISRQCLEPCKKAGMRFGKCMNGKCHCTPK
GVIINVKCKISRQCLKPCKDAGMRFGKCMNGKCHC
GVIINVKCKISPQCLOPCKEAGMRFGKCMNGKCHCTY[Nle]
GVIINVKCKISPQCLKPCKDAGMRFGKCMNGKCHCTY[Nle]
GVIINVKCKISRQCLKPCKDAGMRFGKCMNGKCHCGGG
AVIINVKCKISRQCLEPCKKAGMRFGKCMNGKCHCTPK
RVIINVKCKISRQCLEPCKKAGMRFGKCMNGKCHCTPK
EVIINVKCKISRQCLEPCKKAGMRFGKCMNGKCHCTPK
[1-Nal]VIINVKCKISRQCLEPCKKAGMRFGKCMNGKCHCTPK
WVIINVKCKISRQCLEPCKKAGMRFGKCMNGKCHC
[1Nal]VIINVKCKISRQCLEPCKKAGMRFGKCMN
[1Nal]VIINVKCKISRQCLEPCKKAGMRFGKCMN
WVIINVKCKISRQCLEPCKKAGMRFCKCMNGKCAC
WVWIWVKCKISRQCLEPCKKAGMRFGKCMNGKCAC
[1Nal]V[1Nal]I[1Nal]VKCKISRQCLEPCKK
SCIINVKCKISRQCLEPCKKAGMRFGKCMNGRCHCTCK
SCIINVKCKISRQCLEPCKKAGMRFGKCMNGKCACTCK
SCVIINVKCKISRQCLEPCKKAGMRFGKCMNGKCHCTCK
Any OSK1 peptide analog that comprises an amino acid sequence selected from SEQ ID NOS: 1391 through 4912, 4916, 4920 through 5006, 5009, 5010, and 5012 through 5015 as set forth in Tables 7, 7A, 7B, 7C, 7D, 7E, 7F, 7G, 7H or 7I, is useful in accordance with the present invention. Any of these can also be derivatized at either its N-terminal or C-terminal, e.g., with a fatty acid having from 4 to 10 carbon atoms and from 0 to 2 carbon-carbon double bonds, or a derivative thereof such as an ω-amino-fatty acid. (E.g., Mouhat et al., WO 2006/002850 A2, which is incorporated by reference in its entirety). Examples of such fatty acids include valeric acid or (for the C-terminal) co-amino-valeric acid.
Among useful OSK1 peptide analog sequences of the present invention are analog sequences that introduce amino acid residues that can form an intramolecular covalent bridge (e.g., a disulfide bridge) or non-covalent interactions (e.g. hydrophobic, ionic, stacking) between the first and last beta strand, which may enhance the stability of the structure of the unconjugated or conjugated (e.g., PEGylated) OSK1 peptide analog molecule. Examples of such sequences include SEQ ID NOS: 4985-4987 and 5012-5015.
In some embodiments of the composition of matter, the C-terminal carboxylic acid moiety of the OSK1 peptide analog is replaced with a moiety selected from:
(A) —COOR, where R is independently (C1-C8)alkyl, haloalkyl, aryl or heteroaryl;
(B) —C(═O)NRR, where R is independently hydrogen, (C1-C8)alkyl, haloalkyl, aryl or heteroaryl; and
(C) —CH2OR where R is hydrogen, (C1-C8) alkyl, aryl or heteroaryl.
“Aryl” is phenyl or phenyl vicinally-fused with a saturated, partially-saturated, or unsaturated 3-, 4-, or 5 membered carbon bridge, the phenyl or bridge being substituted by 0, 1, 2 or 3 substituents selected from C18 alkyl, C14 haloalkyl or halo.
“Heteroaryl” is an unsaturated 5, 6 or 7 membered monocyclic or partially-saturated or unsaturated 6-, 7-, 8-, 9-, 10- or 11 membered bicyclic ring, wherein at least one ring is unsaturated, the monocyclic and the bicyclic rings containing 1, 2, 3 or 4 atoms selected from N, O and S, wherein the ring is substituted by 0, 1, 2 or 3 substituents selected from C18 alkyl, C14 haloalkyl and halo.
In other embodiments of the composition of matter comprising a half-life extending moiety, the OSK1 peptide analog comprises an amino acid sequence of the formula:
wherein:
amino acid residues 1 through 7 are optional (Thus, the OSK1 peptide analog optionally includes residues 1-7 as indicated above in SEQ ID NO:5011, or a N-terminal truncation leaving present residues 2-7, 3-7, 4-7, 5-7, 6-7, or 7, or alternatively, a N-terminal truncation wherein all of residues 1-7 are entirely absent.);
In some other embodiments of the composition of matter comprising a half-life extending moiety, the OSK1 peptide analog comprises an amino acid sequence of the formula:
wherein:
In Table 13 and throughout this specification, Xm19 and Xm34 are each independently nonfunctional residues.
Agelenopsis aperta (Agatoxin) toxin peptides and peptide
In accordance with this invention are molecules in which at least one of the toxin peptide (P) portions of the molecule comprises a Kv1.3 antagonist peptide. Amino acid sequences selected from ShK, HmK, MgTx, AgTx1, AgTx2, Heterometrus spinnifer (HsTx1), OSK1, Anuroctoxin (AnTx), Noxiustoxin (NTX), KTX1, Hongotoxin, ChTx, Titystoxin, BgK, BmKTX, BmTx, AeK, AsKS Tc30, Tc32, Pi1, Pi2, and/or Pi3 toxin peptides and peptide analogs of any of these are preferred. Examples of useful Kv1.3 antagonist peptide sequences include those having any amino acid sequence set forth in Table 1, Table 2, Table 3, Table 4, Table 5, Table 6, Table 7, Table 8, Table 9, Table 10, and/or Table 11 herein above;
Other embodiments of the inventive composition include at least one toxin peptide (P) that is an IKCa1 antagonist peptide. Useful IKCa1 antagonist peptides include Maurotoxin (MTx), ChTx, peptides and peptide analogs of either of these, examples of which include those having any amino acid sequence set forth in Table 12, Table 13, and/or Table 14;
Other embodiments of the inventive composition include at least one toxin peptide (P) that is a SKCa inhibitor peptide. Useful SKCa inhibitor peptides include, Apamin, ScyTx, BmP05, P01, P05, Tamapin, TsK, and peptide analogs of any of these, examples of which include those having any amino acid sequence set forth in Table 15;
Other embodiments of the inventive composition include at least one toxin peptide (P) that is an apamin peptide, and peptide analogs of apamin, examples of which include those having any amino acid sequence set forth in Table 16;
Other embodiments of the inventive composition include at least one toxin peptide (P) that is a Scyllotoxin family peptide, and peptide analogs of any of these, examples of which include those having any amino acid sequence set forth in Table 17;
Other embodiments of the inventive composition include at least one toxin peptide (P) that is a BKCa inhibitor peptide, examples of which include those having any amino acid sequence set forth in Table 18;
Other embodiments of the inventive composition include at least one toxin peptide (P) that is a Slotoxin family peptide, and peptide analogs of any of these, examples of which include those having any amino acid sequence set forth in Table 19;
Other embodiments of the inventive composition include at least one toxin peptide (P) that is a Martentoxin peptide, and peptide analogs thereof, examples of which include those having any amino acid sequence set forth in Table 20;
Other embodiments of the inventive composition include at least one toxin peptide (P) that is a N-type Ca2+ channel inhibitor peptide, examples of which include those having any amino acid sequence set forth in Table 21;
Other embodiments of the inventive composition include at least one toxin peptide (P) that is a ωMVIIA peptide, and peptide analogs thereof, examples of which include those having any amino acid sequence set forth in Table 22;
Other embodiments of the inventive composition include at least one toxin peptide (P) that is a ωGVIA peptide, and peptide analogs thereof, examples of which include those having any amino acid sequence set forth in Table 23;
Other embodiments of the inventive composition include at least one toxin peptide (P) that is a Ptu1 peptide, and peptide analogs thereof, examples of which include those having any amino acid sequence set forth in Table 24;
Other embodiments of the inventive composition include at least one toxin peptide (P) that is a ProTx1 peptide, and peptide analogs thereof, examples of which include those having any amino acid sequence set forth in Table 25;
Other embodiments of the inventive composition include at least one toxin peptide (P) that is a BeKM1 peptide, and peptide analogs thereof, examples of which include those having any amino acid sequence set forth in Table 26;
Other embodiments of the inventive composition include at least one toxin peptide (P) that is a Na+ channel inhibitor peptide, examples of which include those having any amino acid sequence set forth in Table 27;
Other embodiments of the inventive composition include at least one toxin peptide (P) that is a Cl− channel inhibitor peptide, examples of which include those having any amino acid sequence set forth in Table 28;
Other embodiments of the inventive composition include at least one toxin peptide (P) that is a Kv2.1 inhibitor peptide, examples of which include those having any amino acid sequence set forth in Table 29;
Other embodiments of the inventive composition include at least one toxin peptide (P) that is a Kv4.2/Kv4.3 inhibitor peptide, examples of which include those having any amino acid sequence set forth in Table 30;
Other embodiments of the inventive composition include at least one toxin peptide (P) that is a nACHR inhibitor peptide, examples of which include those having any amino acid sequence set forth in Table 31; and
Other embodiments of the inventive composition include at least one toxin peptide (P) that is an Agatoxin peptide, a peptide analog thereof or other calcium channel inhibitor peptide, examples of which include those having any amino acid sequence set forth in Table 32.
Half-life extending moieties. This invention involves the presence of at least one half-life extending moiety (F1 and/or F2 in Formula I) attached to a peptide through the N-terminus, C-terminus or a sidechain of one of the intracalary amino acid residues. Multiple half-life extending moieties can also be used; e.g., Fc's at each terminus or an Fc at a terminus and a PEG group at the other terminus or at a sidechain. In other embodiments the Fc domain can be PEGylated (e.g., in accordance with the formulae F1—F2-(L)f-P; P-(L)g-F1—F2; or P-(L)9-F1—F2-(L)f-P).
The half-life extending moiety can be selected such that the inventive composition achieves a sufficient hydrodynamic size to prevent clearance by renal filtration in vivo. For example, a half-life extending moiety can be selected that is a polymeric macromolecule, which is substantially straight chain, branched-chain, or dendritic in form. Alternatively, a half-life extending moiety can be selected such that, in vivo, the inventive composition of matter will bind to a serum protein to form a complex, such that the complex thus formed avoids substantial renal clearance. The half-life extending moiety can be, for example, a lipid; a cholesterol group (such as a steroid); a carbohydrate or oligosaccharide; or any natural or synthetic protein, polypeptide or peptide that binds to a salvage receptor.
Exemplary half-life extending moieties that can be used, in accordance with the present invention, include an immunoglobulin Fc domain, or a portion thereof, or a biologically suitable polymer or copolymer, for example, a polyalkylene glycol compound, such as a polyethylene glycol or a polypropylene glycol. Other appropriate polyalkylene glycol compounds include, but are not limited to, charged or neutral polymers of the following types: dextran, polylysine, colominic acids or other carbohydrate based polymers, polymers of amino acids, and biotin derivatives. In some monomeric fusion protein embodiments an immunoglobulin (including light and heavy chains) or a portion thereof, can be used as a half-life-extending moiety, preferably an immunoglobulin of human origin, and including any of the immunoglobulins, such as, but not limited to, IgG1, IgG2, IgG3 or IgG4.
Other examples of the half-life extending moiety, in accordance with the invention, include a copolymer of ethylene glycol, a copolymer of propylene glycol, a carboxymethylcellulose, a polyvinyl pyrrolidone, a poly-1,3-dioxolane, a poly-1,3,6-trioxane, an ethylene/maleic anhydride copolymer, a polyaminoacid (e.g., polylysine), a dextran n-vinyl pyrrolidone, a poly n-vinyl pyrrolidone, a propylene glycol homopolymer, a propylene oxide polymer, an ethylene oxide polymer, a polyoxyethylated polyol, a polyvinyl alcohol, a linear or branched glycosylated chain, a polyacetal, a long chain fatty acid, a long chain hydrophobic aliphatic group, an immunoglobulin light chain and heavy chain, an immunoglobulin Fc domain or a portion thereof (see, e.g., Feige et al., Modified peptides as therapeutic agents, U.S. Pat. No. 6,660,843), a CH2 domain of Fc, an albumin (e.g., human serum albumin (HSA)); see, e.g., Rosen et al., Albumin fusion proteins, U.S. Pat. No. 6,926,898 and US 2005/0054051; Bridon et al., Protection of endogenous therapeutic peptides from peptidase activity through conjugation to blood components, U.S. Pat. No. 6,887,470), a transthyretin (TTR; see, e.g., Walker et al., Use of transthyretin peptide/protein fusions to increase the serum half-life of pharmacologically active peptides/proteins, US 2003/0195154 A1; 2003/0191056 A1), or a thyroxine-binding globulin (TBG). Thus, exemplary embodiments of the inventive compositions also include HSA fusion constructs such as but not limited to: HSA fusions with ShK, OSK1, or modified analogs of those toxin peptides. Examples include HSA-L10-ShK(2-35); HSA-L10-OsK1(1-38); HSA-L10-ShK(2-35); and HSA-L10-OsK1(1-38).
Other embodiments of the half-life extending moiety, in accordance with the invention, include peptide ligands or small (organic) molecule ligands that have binding affinity for a long half-life serum protein under physiological conditions of temperature, pH, and ionic strength. Examples include an albumin-binding peptide or small molecule ligand, a transthyretin-binding peptide or small molecule ligand, a thyroxine-binding globulin-binding peptide or small molecule ligand, an antibody-binding peptide or small molecule ligand, or another peptide or small molecule that has an affinity for a long half-life serum protein. (See, e.g., Blaney et al., Method and compositions for increasing the serum half-life of pharmacologically active agents by binding to transthyretin-selective ligands, U.S. Pat. No. 5,714,142; Sato et al., Serum albumin binding moieties, US 2003/0069395 A1; Jones et al., Pharmaceutical active conjugates, U.S. Pat. No. 6,342,225). A “long half-life serum protein” is one of the hundreds of different proteins dissolved in mammalian blood plasma, including so-called “carrier proteins” (such as albumin, transferrin and haptoglobin), fibrinogen and other blood coagulation factors, complement components, immunoglobulins, enzyme inhibitors, precursors of substances such as angiotensin and bradykinin and many other types of proteins. The invention encompasses the use of any single species of pharmaceutically acceptable half-life extending moiety, such as, but not limited to, those described herein, or the use of a combination of two or more different half-life extending moieties, such as PEG and immunoglobulin Fc domain or a CH2 domain of Fc, albumin (e.g., HSA), an albumin-binding protein, transthyretin or TBG, or a combination such as immunoglobulin (light chain+heavy chain) and Fc domain (the combination so-called “hemibody”).
In some embodiments of the invention an Fc domain or portion thereof, such as a CH2 domain of Fc, is used as a half-life extending moiety. The Fc domain can be fused to the N-terminal (e.g., in accordance with the formula F1-(L)f-P) or C-terminal (e.g., in accordance with the formula P-(L)g-F1) of the toxin peptides or at both the N and C termini (e.g., in accordance with the formulae F1-(L)f-P-(L)g-F2 or P-(L)g-F1-(L)f-P). A peptide linker sequence can be optionally included between the Fc domain and the toxin peptide, as described herein. Examples of the formula F1-(L)f-P include: Fc-L10-ShK(K22A)[2-35]; Fc-L10-ShK(R1K/K22A)[1-35]; Fc-L10-ShK(R1H/K22A)[1-35]; Fc-L110-ShK(R1Q/K22A)[1-35]; Fc-L110-ShK(R1Y/K22A)[1-35]; Fc-L10-PP-ShK(K22A) [1-35]; and any other working examples described herein. Examples of the formula P-(L)g-F1 include: ShK(1-35)-L10-Fc; OsK1(1-38)-L10-Fc; Met-ShK(1-35)-L10-Fc; ShK(2-35)-L10-Fc; Gly-ShK(1-35)-L10-Fc; Osk1(1-38)-L10-Fc; and any other working examples described herein.
Fc variants are suitable half-life extending moieties within the scope of this invention. A native Fc can be extensively modified to form an Fc variant in accordance with this invention, provided binding to the salvage receptor is maintained; see, for example WO 97/34631, WO 96/32478, and WO 04/110 472. In such Fc variants, one can remove one or more sites of a native Fc that provide structural features or functional activity not required by the fusion molecules of this invention. One can remove these sites by, for example, substituting or deleting residues, inserting residues into the site, or truncating portions containing the site. The inserted or substituted residues can also be altered amino acids, such as peptidomimetics or D-amino acids. Fc variants can be desirable for a number of reasons, several of which are described below. Exemplary Fc variants include molecules and sequences in which:
Preferred Fc variants include the following. In SEQ ID NO: 2, the leucine at position 15 can be substituted with glutamate; the glutamate at position 99, with alanine; and the lysines at positions 101 and 103, with alanines. In addition, phenyalanine residues can replace one or more tyrosine residues.
An alternative half-life extending moiety would be a protein, polypeptide, peptide, antibody, antibody fragment, or small molecule (e.g., a peptidomimetic compound) capable of binding to a salvage receptor. For example, one could use as a half-life extending moiety a polypeptide as described in U.S. Pat. No. 5,739,277, issued Apr. 14, 1998 to Presta et al. Peptides could also be selected by phage display for binding to the FcRn salvage receptor. Such salvage receptor-binding compounds are also included within the meaning of “half-life extending moiety” and are within the scope of this invention. Such half-life extending moieties should be selected for increased half-life (e.g., by avoiding sequences recognized by proteases) and decreased immunogenicity (e.g., by favoring non-immunogenic sequences, as discovered in antibody humanization).
As noted above, polymer half-life extending moieties can also be used for F1 and F2. Various means for attaching chemical moieties useful as half-life extending moieties are currently available, see, e.g., Patent Cooperation Treaty (“PCT”) International Publication No. WO 96/11953, entitled “N-Terminally Chemically Modified Protein Compositions and Methods,” herein incorporated by reference in its entirety. This PCT publication discloses, among other things, the selective attachment of water-soluble polymers to the N-terminus of proteins.
In some embodiments of the inventive compositions, the polymer half-life extending moiety is polyethylene glycol (PEG), as F1 and/or F2, but it should be understood that the inventive composition of matter, beyond positions F1 and/or F2, can also include one or more PEGs conjugated at other sites in the molecule, such as at one or more sites on the toxin peptide. Accordingly, some embodiments of the inventive composition of matter further include one or more PEG moieties conjugated to a non-PEG half-life extending moiety, which is F1 and/or F2, or to the toxin peptide(s) (P), or to any combination of any of these. For example, an Fc domain or portion thereof (as F1 and/or F2) in the inventive composition can be made mono-PEGylated, di-PEGylated, or otherwise multi-PEGylated, by the process of reductive alkylation.
Covalent conjugation of proteins and peptides with poly(ethylene glycol) (PEG) has been widely recognized as an approach to significantly extend the in vivo circulating half-lives of therapeutic proteins. PEGylation achieves this effect predominately by retarding renal clearance, since the PEG moiety adds considerable hydrodynamic radius to the protein. (Zalipsky, S., et al., Use of functionalized poly(ethylene glycol)s for modification of polypeptides., in poly(ethylene glycol) chemistry: Biotechnical and biomedical applications., J. M. Harris, Ed., Plenum Press: New York., 347-370 (1992)). Additional benefits often conferred by PEGylation of proteins and peptides include increased solubility, resistance to proteolytic degradation, and reduced immunogenicity of the therapeutic polypeptide. The merits of protein PEGylation are evidenced by the commercialization of several PEGylated proteins including PEG-Adenosine deaminase (Adagen™/Enzon Corp.), PEG-L-asparaginase (Oncaspar™/Enzon Corp.), PEG-Interferon α-2b (PEG-Intron™/Schering/Enzon), PEG-Interferon α-2a (PEGASYS™/Roche) and PEG-G-CSF (Neulasta™/Amgen) as well as many others in clinical trials.
Briefly, the PEG groups are generally attached to the peptide portion of the composition of the invention via acylation or reductive alkylation (or reductive amination) through a reactive group on the PEG moiety (e.g., an aldehyde, amino, thiol, or ester group) to a reactive group on the inventive compound (e.g., an aldehyde, amino, or ester group).
A useful strategy for the PEGylation of synthetic peptides consists of combining, through forming a conjugate linkage in solution, a peptide and a PEG moiety, each bearing a special functionality that is mutually reactive toward the other. The peptides can be easily prepared with conventional solid phase synthesis (see, for example,
PEG is a well-known, water soluble polymer that is commercially available or can be prepared by ring-opening polymerization of ethylene glycol according to methods well known in the art (Sandler and Karo, Polymer Synthesis, Academic Press, New York, Vol. 3, pages 138-161). In the present application, the term “PEG” is used broadly to encompass any polyethylene glycol molecule, in mono-, bi-, or poly-functional form, without regard to size or to modification at an end of the PEG, and can be represented by the formula:
X—O(CH2CH2O)n-1CH2CH2OH, (X)
where n is 20 to 2300 and X is H or a terminal modification, e.g., a C1-4 alkyl.
In some useful embodiments, a PEG used in the invention terminates on one end with hydroxy or methoxy, i.e., X is H or CH3 (“methoxy PEG”). It is noted that the other end of the PEG, which is shown in formula (II) terminating in OH, covalently attaches to an activating moiety via an ether oxygen bond, an amine linkage, or amide linkage. When used in a chemical structure, the term “PEG” includes the formula (II) above without the hydrogen of the hydroxyl group shown, leaving the oxygen available to react with a free carbon atom of a linker to form an ether bond. More specifically, in order to conjugate PEG to a peptide, the peptide must be reacted with PEG in an “activated” form. Activated PEG can be represented by the formula:
(PEG)-(A) (XI)
where PEG (defined supra) covalently attaches to a carbon atom of the activation moiety (A) to form an ether bond, an amine linkage, or amide linkage, and (A) contains a reactive group which can react with an amino, azido, alkyne, imino, maleimido, N-succinimidyl, carboxyl, aminooxy, seleno, or thiol group on an amino acid residue of a peptide or a linker moiety covalently attached to the peptide, e.g., the OSK1 peptide analog. Residues baring chemoselective reactive groups can be introduced into the toxin peptide, e.g., an OSK1 peptide analog during assembly of the peptide sequence solid-phase synthesis as protected derivatives. Alternatively, chemoselective reactive groups can be introduced in the toxin peptide after assembly of the peptide sequence by solid-phase synthesis via the use of orthogonal protecting groups at specific sites. Examples of amino acid residues useful for chemoselective reactions include, but are not limited to, (amino-oxyacetyl)-L-diaminopropionic acid, p-azido-phenylalanine, azidohomolalanine, para-propargyloxy-phenylalanine, selenocysteine, para-acetylphenylalanine, (Nε-levulinyl)-Lysine, (Nε-pyruvyl)-Lysine, selenocysteine, and orthogonally protected cysteine and homocysteine.
Accordingly, in some embodiments of the composition of matter, the toxin peptide, e.g., the OSK1 peptide analog, is conjugated to a polyethylene glycol (PEG) at:
(a) 1, 2, 3 or 4 amino functionalized sites in the toxin peptide;
(b) 1, 2, 3 or 4 thiol functionalized sites in the toxin peptide; (c) 1 or 2 ketone functionalized sites in the toxin peptide; (d) 1 or 2 azido functionalized sites of the toxin peptide; (e) 1 or 2 carboxyl functionalized sites in the toxin peptide; (f) 1 or 2 aminooxy functionalized sites in the toxin peptide; or (g) 1 or 2 seleno functionalized sites in the toxin peptide.
In other embodiments of the composition of matter, the toxin peptide, e.g., the OSK1 peptide analog, is conjugated to a polyethylene glycol (PEG) at:
(a) 1, 2, 3 or 4 amino functionalized sites of the PEG;
(b) 1, 2, 3 or 4 thiol functionalized sites of the PEG;
(c) 1, 2, 3 or 4 maleimido functionalized sites of the PEG;
(d) 1, 2, 3 or 4 N-succinimidyl functionalized sites of the PEG;
(e) 1, 2, 3 or 4 carboxyl functionalized sites of the PEG; or
(f) 1, 2, 3 or 4 p-nitrophenyloxycarbonyl functionalized sites of the PEG.
Techniques for the preparation of activated PEG and its conjugation to biologically active peptides are well known in the art. (E.g., see U.S. Pat. Nos. 5,643,575, 5,919,455, 5,932,462, and 5,990,237; Thompson et al., PEGylation of polypeptides, EP 0575545 B1; Petit, Site specific protein modification, U.S. Pat. Nos. 6,451,986, and 6,548,644; S. Herman et al., Poly(ethylene glycol) with reactive endgroups: I. Modification of proteins, J. Bioactive Compatible Polymers, 10:145-187 (1995); Y. Lu et al., Pegylated peptides III: Solid-phase synthesis with PEGylating reagents of varying molecular weight: synthesis of multiply PEGylated peptides, Reactive Polymers, 22:221-229 (1994); A. M. Felix et al., PEGylated Peptides IV: Enhanced biological activity of site-directed PEGylated GRF analogs, Int. J. Peptide Protein Res., 46:253-264 (1995); A. M. Felix, Site-specific poly(ethylene glycol)ylation of peptides, ACS Symposium Series 680(poly(ethylene glycol)): 218-238 (1997); Y. Ikeda et al., Polyethylene glycol derivatives, their modified peptides, methods for producing them and use of the modified peptides, EP 0473084 B1; G. E. Means et al., Selected techniques for the modification of protein side chains, in: Chemical modification of proteins, Holden Day, Inc., 219 (1971)).
Activated PEG, such as PEG-aldehydes or PEG-aldehyde hydrates, can be chemically synthesized by known means or obtained from commercial sources, e.g., Shearwater Polymers, (Huntsville, Ala.) or Enzon, Inc. (Piscataway, N.J.).
An example of a useful activated PEG for purposes of the present invention is a PEG-aldehyde compound (e.g., a methoxy PEG-aldehyde), such as PEG-propionaldehyde, which is commercially available from Shearwater Polymers (Huntsville, Ala.). PEG-propionaldehyde is represented by the formula PEG-CH2CH2CHO. (See, e.g., U.S. Pat. No. 5,252,714). Other examples of useful activated PEG are PEG acetaldehyde hydrate and PEG bis aldehyde hydrate, which latter yields a bifunctionally activated structure. (See., e.g., Bentley et al., Poly(ethylene glycol) aldehyde hydrates and related polymers and applications in modifying amines, U.S. Pat. No. 5,990,237).
Another useful activated PEG for generating the PEG-conjugated peptides of the present invention is a PEG-maleimide compound, such as, but not limited to, a methoxy PEG-maleimide, such as maleimido monomethoxy PEG, are particularly useful for generating the PEG-conjugated peptides of the invention. (E.g., Shen, N-maleimidyl polymer derivatives, U.S. Pat. No. 6,602,498; C. Delgado et al., The uses and properties of PEG-linked proteins., Crit. Rev. Therap. Drug Carrier Systems, 9:249-304 (1992); S. Zalipsky et al., Use of functionalized poly(ethylene glycol)s for modification of polypeptides, in: Poly(ethylene glycol) chemistry: Biotechnical and biomedical applications (J. M. Harris, Editor, Plenum Press: New York, 347-370 (1992); S. Herman et al., Poly(ethylene glycol) with reactive endgroups: I. Modification of proteins, J. Bioactive Compatible Polymers, 10:145-187 (1995); P. J. Shadle et al., Conjugation of polymer to colony stimulating factor-1, U.S. Pat. No. 4,847,325; G. Shaw et al., Cysteine added variants IL-3 and chemical modifications thereof, U.S. Pat. No. 5,166,322 and EP 0469074 B1; G. Shaw et al., Cysteine added variants of EPO and chemical modifications thereof, EP 0668353 A1; G. Shaw et al., Cysteine added variants G-CSF and chemical modifications thereof, EP 0668354 A1; N. V. Katre et al., Interleukin-2 muteins and polymer conjugation thereof, U.S. Pat. No. 5,206,344; R. J. Goodson and N. V. Katre, Site-directed pegylation of recombinant interleukin-2 at its glycosylation site, Biotechnology, 8:343-346 (1990)).
A poly(ethylene glycol) vinyl sulfone is another useful activated PEG for generating the PEG-conjugated peptides of the present invention by conjugation at thiolated amino acid residues, e.g., at C residues. (E.g., M. Morpurgo et al., Preparation and characterization of poly(ethylene glycol) vinyl sulfone, Bioconj. Chem., 7:363-368 (1996); see also Harris, Functionalization of polyethylene glycol for formation of active sulfone-terminated PEG derivatives for binding to proteins and biologically compatible materials, U.S. Pat. Nos. 5,446,090; 5,739,208; 5,900,461; 6,610,281 and 6,894,025; and Harris, Water soluble active sulfones of poly(ethylene glycol), WO 95/13312 A1).
Another activated form of PEG that is useful in accordance with the present invention, is a PEG-N-hydroxysuccinimide ester compound, for example, methoxy PEG-N-hydroxysuccinimidyl (NHS) ester.
Heterobifunctionally activated forms of PEG are also useful. (See, e.g., Thompson et al., PEGylation reagents and biologically active compounds formed therewith, U.S. Pat. No. 6,552,170).
Typically, a toxin peptide or, a fusion protein comprising the toxin peptide, is reacted by known chemical techniques with an activated PEG compound, such as but not limited to, a thiol-activated PEG compound, a diol-activated PEG compound, a PEG-hydrazide compound, a PEG-oxyamine compound, or a PEG-bromoacetyl compound. (See, e.g., S. Herman, Poly(ethylene glycol) with Reactive Endgroups: I. Modification of Proteins, J. Bioactive and Compatible Polymers, 10:145-187 (1995); S. Zalipsky, Chemistry of Polyethylene Glycol Conjugates with Biologically Active Molecules, Advanced Drug Delivery Reviews, 16:157-182 (1995); R. Greenwald et al., Poly(ethylene glycol) conjugated drugs and prodrugs: a comprehensive review, Critical Reviews in Therapeutic Drug Carrier Systems, 17:101-161 (2000)).
Methods for N-terminal PEGylation are exemplified herein in Examples 31-34, 45 and 47-48, but these are in no way limiting of the PEGylation methods that can be employed by one skilled in the art.
Any molecular mass for a PEG can be used as practically desired, e.g., from about 1,000 or 2,000 Daltons (Da) to about 100,000 Da (n is 20 to 2300). Preferably, the combined or total molecular mass of PEG used in a PEG-conjugated peptide of the present invention is from about 3,000 Da or 5,000 Da, to about 50,000 Da or 60,000 Da (total n is from 70 to 1,400), more preferably from about 10,000 Da to about 40,000 Da (total n is about 230 to about 910). The most preferred combined mass for PEG is from about 20,000 Da to about 30,000 Da (total n is about 450 to about 680). The number of repeating units “n” in the PEG is approximated for the molecular mass described in Daltons. It is preferred that the combined molecular mass of PEG on an activated linker is suitable for pharmaceutical use. Thus, the combined molecular mass of the PEG molecule should not exceed about 100,000 Da.
Polysaccharide polymers are another type of water-soluble polymer that can be used for protein modification. Dextrans are polysaccharide polymers comprised of individual subunits of glucose predominantly linked by α1-6 linkages. The dextran itself is available in many molecular weight ranges, and is readily available in molecular weights from about 1 kDa to about 70 kDa. Dextran is a suitable water-soluble polymer for use in the present invention as a half-life extending moiety by itself or in combination with another half-life extending moiety (e.g., Fc). See, for example, WO 96/11953 and WO 96/05309. The use of dextran conjugated to therapeutic or diagnostic immunoglobulins has been reported; see, for example, European Patent Publication No. 0 315 456, which is hereby incorporated by reference in its entirety. Dextran of about 1 kDa to about 20 kDa is preferred when dextran is used as a half-life extending moiety in accordance with the present invention.
Linkers. Any “linker” group or moiety (i.e., “-(L)g-” or “-(L)g-” in Formulae I-IX) is optional. When present, its chemical structure is not critical, since it serves primarily as a spacer. As stated herein above, the linker moiety (-(L)f- and/or -(L)g-), if present, can be independently the same or different from any other linker, or linkers, that may be present in the inventive composition. For example, an “(L)f” can represent the same moiety as, or a different moiety from, any other “(L)f” or any “(L)g” in accordance with the invention. The linker is preferably made up of amino acids linked together by peptide bonds. Some of these amino acids can be glycosylated, as is well understood by those in the art. For example, a useful linker sequence constituting a sialylation site is X1X2NX4X5G (SEQ ID NO: 637), wherein X1, X2, X4 and X5 are each independently any amino acid residue.
As stated above, in some embodiments, a peptidyl linker is present (i.e., made up of amino acids linked together by peptide bonds) that is made in length, preferably, of from 1 up to about 40 amino acid residues, more preferably, of from 1 up to about 20 amino acid residues, and most preferably of from 1 to about 10 amino acid residues. Preferably, but not necessarily, the amino acid residues in the linker are from among the twenty canonical amino acids, more preferably, cysteine, glycine, alanine, proline, asparagine, glutamine, and/or serine. Even more preferably, a peptidyl linker is made up of a majority of amino acids that are sterically unhindered, such as glycine, serine, and alanine linked by a peptide bond. It is also desirable that, if present, a peptidyl linker be selected that avoids rapid proteolytic turnover in circulation in vivo. Thus, preferred linkers include polyglycines (particularly (Gly)4 (SEQ ID NO: 4918), (Gly)5) (SEQ ID NO: 4919), poly(Gly-Ala), and polyalanines. Other preferred linkers are those identified herein as “L5” (GGGGS; SEQ ID NO: 638), “L10” (GGGGSGGGGS; SEQ ID NO:79), “L25” GGGGSGGGGSGGGGSGGGGSGGGGS; SEQ ID NO:84) and any linkers used in the working examples hereinafter. The linkers described herein, however, are exemplary; linkers within the scope of this invention can be much longer and can include other residues.
In some embodiments of the compositions of this invention, which comprise a peptide linker moiety (L), acidic residues, for example, glutamate or aspartate residues, are placed in the amino acid sequence of the linker moiety (L). Examples include the following peptide linker sequences:
In other embodiments, the linker constitutes a phosphorylation site, e.g., X1X2YX3X4G (SEQ ID NO: 654), wherein X1, X2, X3 and X4 are each independently any amino acid residue; X1X2SX3X4G (SEQ ID NO: 655), wherein X1, X2, X3 and X4 are each independently any amino acid residue; or X1X2TX3X4G (SEQ ID NO: 656), wherein X1, X2, X3 and X4 are each independently any amino acid residue.
Non-peptide linkers are also possible. For example, alkyl linkers such as —NH—(CH2)s—C(O)—, wherein s=2-20 could be used. These alkyl linkers can further be substituted by any non-sterically hindering group such as lower alkyl (e.g., C1-C6) lower acyl, halogen (e.g., Cl, Br), CN, NH2, phenyl, etc. An exemplary non-peptide linker is a PEG linker,
wherein n is such that the linker has a molecular weight of 100 to 5000 kDa, preferably 100 to 500 kDa. The peptide linkers can be altered to form derivatives in the same manner as described above.
Useful linker embodiments also include aminoethyloxyethyloxy-acetyl linkers as disclosed by Chandy et al. (Chandy et al., WO 2006/042151 A2, incorporated herein by reference in its entirety).
Derivatives. The inventors also contemplate derivatizing the peptide and/or half-life extending moiety portion of the compounds. Such derivatives can improve the solubility, absorption, biological half-life, and the like of the compounds. The moieties can alternatively eliminate or attenuate any undesirable side-effect of the compounds and the like. Exemplary derivatives include compounds in which:
Lysinyl residues and amino terminal residues can be reacted with succinic or other carboxylic acid anhydrides, which reverse the charge of the lysinyl residues. Other suitable reagents for derivatizing alpha-amino-containing residues include imidoesters such as methyl picolinimidate; pyridoxal phosphate; pyridoxal; chloroborohydride; trinitrobenzenesulfonic acid; O-methylisourea; 2,4 pentanedione; and transaminase-catalyzed reaction with glyoxylate.
Arginyl residues can be modified by reaction with any one or combination of several conventional reagents, including phenylglyoxal, 2,3-butanedione, 1,2-cyclohexanedione, and ninhydrin. Derivatization of arginyl residues requires that the reaction be performed in alkaline conditions because of the high pKa of the guanidine functional group. Furthermore, these reagents can react with the groups of lysine as well as the arginine epsilon-amino group.
Specific modification of tyrosyl residues has been studied extensively, with particular interest in introducing spectral labels into tyrosyl residues by reaction with aromatic diazonium compounds or tetranitromethane. Most commonly, N-acetylimidizole and tetranitromethane are used to form O-acetyl tyrosyl species and 3-nitro derivatives, respectively.
Carboxyl sidechain groups (aspartyl or glutamyl) can be selectively modified by reaction with carbodiimides (R′—N═C═N—R′) such as 1-cyclohexyl-3-(2-morpholinyl-(4-ethyl) carbodiimide or 1-ethyl-3-(4-azonia-4,4-dimethylpentyl) carbodiimide. Furthermore, aspartyl and glutamyl residues can be converted to asparaginyl and glutaminyl residues by reaction with ammonium ions.
Glutaminyl and asparaginyl residues can be deamidated to the corresponding glutamyl and aspartyl residues. Alternatively, these residues are deamidated under mildly acidic conditions. Either form of these residues falls within the scope of this invention.
Cysteinyl residues can be replaced by amino acid residues or other moieties either to eliminate disulfide bonding or, conversely, to stabilize cross-linking. See, e.g., Bhatnagar et al. (1996), J. Med. Chem. 39: 3814-9.
Derivatization with bifunctional agents is useful for cross-linking the peptides or their functional derivatives to a water-insoluble support matrix or to other macromolecular half-life extending moieties. Commonly used cross-linking agents include, e.g., 1,1-bis(diazoacetyl)-2-phenylethane, glutaraldehyde, N-hydroxysuccinimide esters, for example, esters with 4-azidosalicylic acid, homobifunctional imidoesters, including disuccinimidyl esters such as 3,3′-dithiobis(succinimidylpropionate), and bifunctional maleimides such as bis-N-maleimido-1,8-octane. Derivatizing agents such as methyl-3-[(p-azidophenyl)dithio]propioimidate yield photoactivatable intermediates that are capable of forming crosslinks in the presence of light. Alternatively, reactive water-insoluble matrices such as cyanogen bromide-activated carbohydrates and the reactive substrates described in U.S. Pat. Nos. 3,969,287; 3,691,016; 4,195,128; 4,247,642; 4,229,537; and 4,330,440 are employed for protein immobilization.
Carbohydrate (oligosaccharide) groups can conveniently be attached to sites that are known to be glycosylation sites in proteins. Generally, O-linked oligosaccharides are attached to serine (Ser) or threonine (Thr) residues while N-linked oligosaccharides are attached to asparagine (Asn) residues when they are part of the sequence Asn-X-Ser/Thr, where X can be any amino acid except proline. X is preferably one of the 19 naturally occurring amino acids other than proline. The structures of N-linked and O-linked oligosaccharides and the sugar residues found in each type are different. One type of sugar that is commonly found on both is N-acetylneuraminic acid (referred to as sialic acid). Sialic acid is usually the terminal residue of both N-linked and O-linked oligosaccharides and, by virtue of its negative charge, can confer acidic properties to the glycosylated compound. Such site(s) can be incorporated in the linker of the compounds of this invention and are preferably glycosylated by a cell during recombinant production of the polypeptide compounds (e.g., in mammalian cells such as CHO, BHK, COS). However, such sites can further be glycosylated by synthetic or semi-synthetic procedures known in the art.
Other possible modifications include hydroxylation of proline and lysine, phosphorylation of hydroxyl groups of seryl or threonyl residues, oxidation of the sulfur atom in Cys, methylation of the alpha-amino groups of lysine, arginine, and histidine side chains. Creighton, Proteins: Structure and Molecule Properties (W. H. Freeman and Co., San Francisco), pp. 79-86 (1983).
Compounds of the present invention can be changed at the DNA level, as well. The DNA sequence of any portion of the compound can be changed to codons more compatible with the chosen host cell. For E. coli, which is the preferred host cell, optimized codons are known in the art. Codons can be substituted to eliminate restriction sites or to include silent restriction sites, which can aid in processing of the DNA in the selected host cell. The half-life extending moiety, linker and peptide DNA sequences can be modified to include any of the foregoing sequence changes.
A process for preparing conjugation derivatives is also contemplated. Tumor cells, for example, exhibit epitopes not found on their normal counterparts. Such epitopes include, for example, different post-translational modifications resulting from their rapid proliferation. Thus, one aspect of this invention is a process comprising:
Methods of Making
The present invention also relates to nucleic acids, expression vectors and host cells useful in producing the polypeptides of the present invention. Host cells can be eukaryotic cells, with mammalian cells preferred and CHO cells most preferred. Host cells can also be prokaryotic cells, with E. coli cells most preferred.
The compounds of this invention largely can be made in transformed host cells using recombinant DNA techniques. To do so, a recombinant DNA molecule coding for the peptide is prepared. Methods of preparing such DNA molecules are well known in the art. For instance, sequences coding for the peptides could be excised from DNA using suitable restriction enzymes. Alternatively, the DNA molecule could be synthesized using chemical synthesis techniques, such as the phosphoramidate method. Also, a combination of these techniques could be used.
The invention also includes a vector capable of expressing the peptides in an appropriate host. The vector comprises the DNA molecule that codes for the peptides operatively linked to appropriate expression control sequences. Methods of effecting this operative linking, either before or after the DNA molecule is inserted into the vector, are well known. Expression control sequences include promoters, activators, enhancers, operators, ribosomal binding sites, start signals, stop signals, cap signals, polyadenylation signals, and other signals involved with the control of transcription or translation.
The resulting vector having the DNA molecule thereon is used to transform an appropriate host. This transformation can be performed using methods well known in the art.
Any of a large number of available and well-known host cells can be used in the practice of this invention. The selection of a particular host is dependent upon a number of factors recognized by the art. These include, for example, compatibility with the chosen expression vector, toxicity of the peptides encoded by the DNA molecule, rate of transformation, ease of recovery of the peptides, expression characteristics, bio-safety and costs. A balance of these factors must be struck with the understanding that not all hosts can be equally effective for the expression of a particular DNA sequence. Within these general guidelines, useful microbial hosts include bacteria (such as E. coli sp.), yeast (such as Saccharomyces sp.) and other fungi, insects, plants, mammalian (including human) cells in culture, or other hosts known in the art.
Next, the transformed host is cultured and purified. Host cells can be cultured under conventional fermentation conditions so that the desired compounds are expressed. Such fermentation conditions are well known in the art. Finally, the peptides are purified from culture by methods well known in the art.
In some embodiments of the inventive DNA, the DNA encodes a recombinant fusion protein composition of the invention, preferably, but not necessarily, monovalent with respect to the toxin peptide, for expression in a mammalian cell, such as, but not limited to, CHO or HEK293. The encoded fusion protein includes (a)-(c) immediately below, in the N-terminal to C-terminal direction:
(a) an immunoglobulin, which includes the constant and variable regions of the immunoglobulin light and heavy chains, or a portion of an immunoglobulin (e.g., an Fc domain, or the variable regions of the light and heavy chains); if both immunoglobulin light chain and heavy chain components are to be included in the construct, then a peptidyl linker, as further described in (b) immediately below, is also included to separate the immunoglobulin components (See, e.g.,
(b) a peptidyl linker, which is at least 4 (or 5) amino acid residues long and comprises at least one protease cleavage site (e.g., a furin cleavage site, which is particularly useful for intracellular cleavage of the expressed fusion protein); typically, the peptidyl linker sequence can be up to about 35 to 45 amino acid residues long (e.g., a 7×L5 linker modified to include the desired protease cleavage site(s)), but linkers up to about 100 to about 300 amino acid residues long are also useful; and
(c) an immunoglobulin Fc domain or a portion thereof. The Fc domain of (c) can be from the same type of immunoglobulin in (a), or different. In such embodiments, the DNA encodes a toxin peptide covalently linked to the N-terminal or C-terminal end of (a) or (c) above, either directly or indirectly via a peptidyl linker (a linker minus a protease cleavage site). Any toxin peptide or peptide analog thereof as described herein can be encoded by the DNA (e.g., but not limited to, ShK, HmK, MgTx, AgTx1, AgTx2, HsTx1, OSK1, Anuroctoxin, Noxiustoxin, Hongotoxin, HsTx1, ChTx, MTx, Titystoxin, BgK, BmKTX, BmTx, Tc30, Tc32, Pi1, Pi2, Pi3 toxin peptide, or a peptide analog of any of these). For example, an OSK1 peptide analog comprising an amino acid sequence selected from SEQ ID NOS: 25, 294 through 298, 562 through 636, 980 through 1274, 1303, 1308, 1391 through 4912, 4916, 4920 through 5006, 5009, 5010, and 5012 through 5015, as set forth in Tables 7 and Tables 7A-J, can be employed. Alternatively, an ShK peptide analog comprising an amino acid sequence selected from SEQ ID NOS: 5, 88 through 200, 548 through 561, 884 through 950, and 1295 through 1300 as set forth in Table 2, can be employed. Any other toxin peptide sequence described herein that can alternatively be expressed recombinantly using recombinant and protein engineering techniques known in the art can also be used. The immunoglobulin of (a) and (c) above can be in each instance independently selected from any desired type, such as but not limited to, IgG1, IgG2, IgG3, and IgG4. The variable regions can be non-functional in vivo (e.g., CDRs specifically binding KLH), or alternatively, if targeting enhancement function is also desired, the variable regions can be chosen to specifically bind (non-competitively) the ion channel target of the toxin peptide (e.g., Kv1.3) or specifically bind another antigen typically found associated with, or in the vicinity of, the target ion channel. In addition, the inventive DNA optionally further encodes, 5′ to the coding region of (a) above, a signal peptide sequence (e.g., a secretory signal peptide) operably linked to the expressed fusion protein. An example of the inventive DNA encoding a recombinant fusion protein for expression in a mammalian cell, described immediately above, is a DNA that encodes a fusion protein comprising, in the N-terminal to C-terminal direction:
In some embodiments particularly suited for the recombinant expression of monovalent dimeric Fc-toxin peptide fusions or “peptibodies” (see,
DNA constructs similar to those described above are also useful for recombinant expression by mammalian cells of other dimeric Fc fusion proteins (“peptibodies”) or chimeric immunoglobulin (light chain+heavy chain)-Fc heterotrimers (“hemibodies”), conjugated to pharmacologically active peptides (e.g., agonist or antagonist peptides) other than toxin peptides.
Peptide compositions of the present invention can also be made by synthetic methods. Solid phase synthesis is the preferred technique of making individual peptides since it is the most cost-effective method of making small peptides. For example, well known solid phase synthesis techniques include the use of protecting groups, linkers, and solid phase supports, as well as specific protection and deprotection reaction conditions, linker cleavage conditions, use of scavengers, and other aspects of solid phase peptide synthesis. Suitable techniques are well known in the art. (E.g., Merrifield (1973), Chem. Polypeptides, pp. 335-61 (Katsoyannis and Panayotis eds.); Merrifield (1963), J. Am. Chem. Soc. 85: 2149; Davis et al. (1985), Biochem. Intl. 10: 394-414; Stewart and Young (1969), Solid Phase Peptide Synthesis; U.S. Pat. No. 3,941,763; Finn et al. (1976), The Proteins (3rd ed.) 2: 105-253; and Erickson et al. (1976), The Proteins (3rd ed.) 2: 257-527; “Protecting Groups in Organic Synthesis,” 3rd Edition, T. W. Greene and P. G. M. Wuts, Eds., John Wiley & Sons, Inc., 1999; NovaBiochem Catalog, 2000; “Synthetic Peptides, A User's Guide,” G. A. Grant, Ed., W.H. Freeman & Company, New York, N.Y., 1992; “Advanced Chemtech Handbook of Combinatorial & Solid Phase Organic Chemistry,” W. D. Bennet, J. W. Christensen, L. K. Hamaker, M. L. Peterson, M. R. Rhodes, and H. H. Saneii, Eds., Advanced Chemtech, 1998; “Principles of Peptide Synthesis, 2nd ed.,” M. Bodanszky, Ed., Springer-Verlag, 1993; “The Practice of Peptide Synthesis, 2nd ed.,” M. Bodanszky and A. Bodanszky, Eds., Springer-Verlag, 1994; “Protecting Groups,” P. J. Kocienski, Ed., Georg Thieme Verlag, Stuttgart, Germany, 1994; “Fmoc Solid Phase Peptide Synthesis, A Practical Approach,” W. C. Chan and P. D. White, Eds., Oxford Press, 2000, G. B. Fields et al., Synthetic Peptides: A User's Guide, 1990, 77-183).
Whether the compositions of the present invention are prepared by synthetic or recombinant techniques, suitable protein purification techniques can also be involved, when applicable. In some embodiments of the compositions of the invention, the toxin peptide portion and/or the half-life extending portion, or any other portion, can be prepared to include a suitable isotopic label (e.g., 125I, 14C, 13C, 35S, 3H, 2H, 13N, 15N, 15O, 17O, etc.), for ease of quantification or detection.
Compounds that contain derivatized peptides or which contain non-peptide groups can be synthesized by well-known organic chemistry techniques.
Uses of the Compounds
In general. The compounds of this invention have pharmacologic activity resulting from their ability to bind to proteins of interest as agonists, mimetics or antagonists of the native ligands of such proteins of interest. Heritable diseases that have a known linkage to ion channels (“channelopathies”) cover various fields of medicine, some of which include neurology, nephrology, myology and cardiology. A list of inherited disorders attributed to ion channels includes:
In addition to the aforementioned disorders, evidence has also been provided supporting ion channels as targets for treatment of:
Both agonists and antagonists of ion channels can achieve therapeutic benefit. Therapeutic benefits can result, for example, from antagonizing Kv1.3, IKCa1, SKCa, BKCa, N-type or T-type Ca2+ channels and the like. Small molecule and peptide antagonists of these channels have been shown to possess utility in vitro and in vivo. Limitations in production efficiency and pharmacokinetics, however, have largely prevented clinical investigation of inhibitor peptides of ion channels.
Compositions of this invention incorporating peptide antagonists of the voltage-gated potassium channel Kv1.3, in particular OSK1 peptide analogs, whether or not conjugated to a half-life extending moiety, are useful as immunosuppressive agents with therapeutic value for autoimmune diseases. For example, such molecules are useful in treating multiple sclerosis, type 1 diabetes, psoriasis, inflammatory bowel disease, and rheumatoid arthritis. (See, e.g., H. Wulff et al. (2003) J. Clin. Invest. 111, 1703-1713 and H. Rus et al. (2005) PNAS 102, 11094-11099; Beeton et al., Targeting effector memory T cells with a selective inhibitor peptide of Kv1.3 channels for therapy of autoimmune diseases, Molec. Pharmacol. 67(4):1369-81 (2005); 1 Beeton et al. (2006), Kv1.3: therapeutic target for cell-mediated autoimmune disease, electronic preprint at //webfiles.uci.edu/xythoswfs/webui/2670029.1). Inhibitors of the voltage-gated potassium channel Kv1.3 have been examined in a variety of preclinical animal models of inflammation. Small molecule and peptide inhibitors of Kv1.3 have been shown to block delayed type hypersensitivity responses to ovalbumin [C. Beeton et al. (2005) Mol. Pharmacol. 67, 1369] and tetanus toxoid [G. C. Koo et al. (1999) Clin. Immunol. 197, 99]. In addition to suppressing inflammation in the skin, inhibitors also reduced antibody production [G. C. Koo et al. (1997) J. Immunol. 158, 5120]. Kv1.3 antagonists have shown efficacy in a rat adoptive-transfer experimental autoimmune encephalomyelitis (AT-EAE) model of multiple sclerosis (MS). The Kv1.3 channel is overexpressed on myelin-specific T cells from MS patients, lending further support to the utility Kv1.3 inhibitors may provide in treating MS. Inflammatory bone resorption was also suppressed by Kv1.3 inhibitors in a preclinical adoptive-transfer model of periodontal disease [P. Valverde et al. (2004) J. Bone Mineral Res. 19, 155]. In this study, inhibitors additionally blocked antibody production to a bacterial outer membrane protein,—one component of the bacteria used to induce gingival inflammation. Recently in preclinical rat models, efficacy of Kv1.3 inhibitors was shown in treating pristane-induced arthritis and diabetes [C. Beeton et al. (2006) preprint available at //webfiles.uci.edu/xythoswfs/webui/_xy-2670029—1.]. The Kv1.3 channel is expressed on all subsets of T cells and B cells, but effector memory T cells and class-switched memory B cells are particularly dependent on Kv1.3 [H. Wulff et al. (2004) J. Immunol. 173, 776]. Gad5/insulin-specific T cells from patients with new onset type 1 diabetes, myelin-specific T cells from MS patients and T cells from the synovium of rheumatoid arthritis patients all overexpress Kv1.3 [C. Beeton et al. (2006) preprint at //webfiles.uci.edu/xythoswfs/webui/_xy-2670029—1.]. Because mice deficient in Kv1.3 gained less weight when placed on a high fat diet [J. Xu et al. (2003) Human Mol. Genet. 12, 551] and showed altered glucose utilization [J. Xu et al. (2004) Proc. Natl. Acad. Sci. 101, 3112], Kv1.3 is also being investigated for the treatment of obesity and diabetes. Breast cancer specimens [M. Abdul et al. (2003) Anticancer Res. 23, 3347] and prostate cancer cell lines [S. P. Fraser et al. (2003) Pflugers Arch. 446, 559] have also been shown to express Kv1.3, and Kv1.3 blockade may be of utility for treatment of cancer. Disorders that can be treated in accordance with the inventive method of treating an autoimmune disorder, involving Kv1.3 inhibitor toxin peptide(s), include multiple sclerosis, type 1 diabetes, psoriasis, inflammatory bowel disease, contact-mediated dermatitis, rheumatoid arthritis, psoriatic arthritis, asthma, allergy, restinosis, systemic sclerosis, fibrosis, scleroderma, glomerulonephritis, Sjogren syndrome, inflammatory bone resorption, transplant rejection, graft-versus-host disease, and systemic lupus erythematosus (SLE) and other forms of lupus.
Some of the cells that express the calcium-activated potassium of intermediate conductance IKCa1 include T cells, B cells, mast cells and red blood cells (RBCs). T cells and RBCs from mice deficient in IKCa1 show defects in volume regulation [T. Begenisich et al. (2004) J. Biol. Chem. 279, 47681]. Preclinical and clinical studies have demonstrated IKCa1 inhibitors utility in treating sickle cell anemia [J. W. Stocker et al. (2003) Blood 101, 2412; www.icagen.com]. Blockers of the IKCa1 channel have also been shown to block EAE, indicating they may possess utility in treatment of MS [E. P. Reich et al. (2005) Eur. J. Immunol. 35, 1027]. IgE-mediated histamine production from mast cells is also blocked by IKCa1 inhibitors [S. Mark Duffy et al. (2004) J. Allergy Clin. Immunol. 114, 66], therefore they may also be of benefit in treating asthma. The IKCa1 channel is overexpressed on activated T and B lymphocytes [H. Wulff et al. (2004) J. Immunol. 173, 776] and thus may show utility in treatment of a wide variety of immune disorders. Outside of the immune system, IKCa1 inhibitors have also shown efficacy in a rat model of vascular restinosis and thus might represent a new therapeutic strategy to prevent restenosis after angioplasty [R. Kohler et al. (2003) Circulation 108, 1119]. It is also thought that IKCa1 antagonists are of utility in treatment of tumor angiogenesis since inhibitors suppressed endothelial cell proliferation and angionenesis in vivo [I. Grgic et al. (2005) Arterioscler. Thromb. Vasc. Biol. 25, 704]. The IKCa1 channel is upregulated in pancreatic tumors and inhibitors blocked proliferation of pancreatic tumor cell lines [H. Jager et al. (2004) Mol Pharmacol. 65, 630]. IKCa1 antagonists may also represent an approach to attenuate acute brain damage caused by traumatic brain injury [F. Mauler (2004) Eur. J. Neurosci. 20, 1761]. Disorders that can be treated with IKCa1 inhibitors include multiple sclerosis, asthma, psoriasis, contact-mediated dermatitis, rheumatoid & psoriatic arthritis, inflammatory bowel disease, transplant rejection, graft-versus-host disease, Lupus, restinosis, pancreatic cancer, tumor angiogenesis and traumatic brain injury.
Accordingly, molecules of this invention incorporating peptide antagonists of the calcium-activated potassium channel of intermediate conductance, IKCa can be used to treat immune dysfunction, multiple sclerosis, type 1 diabetes, psoriasis, inflammatory bowel disease, contact-mediated dermatitis, rheumatoid arthritis, psoriatic arthritis, asthma, allergy, restinosis, systemic sclerosis, fibrosis, scleroderma, glomerulonephritis, Sjogren syndrome, inflammatory bone resorption, transplant rejection, graft-versus-host disease, and lupus.
Accordingly, the present invention includes a method of treating an autoimmune disorder, which involves administering to a patient who has been diagnosed with an autoimmune disorder, such as multiple sclerosis, type 1 diabetes, psoriasis, inflammatory bowel disease, contact-mediated dermatitis, rheumatoid arthritis, psoriatic arthritis, asthma, allergy, restinosis, systemic sclerosis, fibrosis, scleroderma, glomerulonephritis, Sjogren syndrome, inflammatory bone resorption, transplant rejection, graft-versus-host disease, or lupus, a therapeutically effective amount of the inventive composition of matter, whereby at least one symptom of the disorder is alleviated in the patient. “Alleviated” means to be lessened, lightened, diminished, softened, mitigated (i.e., made more mild or gentle), quieted, assuaged, abated, relieved, nullified, or allayed, regardless of whether the symptom of interest is entirely erased, eradicated, eliminated, or prevented in a particular patient.
The present invention is further directed to a method of preventing or mitigating a relapse of a symptom of multiple sclerosis, which method involves administering to a patient, who has previously experienced at least one symptom of multiple sclerosis, a prophylactically effective amount of the inventive composition of matter, such that the at least one symptom of multiple sclerosis is prevented from recurring or is mitigated.
The inventive compositions of matter preferred for use in practicing the inventive method of treating an autoimmune disorder, e.g., inflammatory bowel disease (IBD, including Crohn's Disease and ulcerative colitis), and the method of preventing or mitigating a relapse of a symptom of multiple sclerosis include as P (conjugated as in Formula I), a Kv1.3 or IKCa1 antagonist peptide, such as a ShK peptide, an OSK1 peptide or an OSK1 peptide analog, a ChTx peptide and/or a Maurotoxin (MTx) peptide, or peptide analogs of any of these.
For example, the conjugated ShK peptide or ShK peptide analog can comprise an amino acid sequence selected from the following:
The conjugated OSK1 peptide, or conjugated or unconjugated OSK1 peptide analog, can comprise an amino acid sequence selected from the following:
Also by way of example, a the conjugated MTX peptide, MTX peptide analog, ChTx peptide or ChTx peptide analog can comprise an amino acid sequence selected from:
Also useful in these methods conjugated, or unconjugated, are a Kv1.3 or IKCa1 inhibitor toxin peptide analog that comprises an amino acid sequence selected from:
In accordance with these inventive methods, a patient who has been diagnosed with an autoimmune disorder, such as, but not limited to multiple sclerosis, type 1 diabetes, psoriasis, inflammatory bowel disease, contact-mediated dermatitis, rheumatoid arthritis, psoratic arthritis, asthma, allergy, restinosis, systemic sclerosis, fibrosis, scleroderma, glomerulonephritis, Sjogren syndrome, inflammatory bone resorption, transplant rejection, graft-versus-host disease, or lupus, or a patient who has previously experienced at least one symptom of multiple sclerosis, are well-recognizable and/or diagnosed by the skilled practitioner, such as a physician, familiar with autoimmune disorders and their symptoms.
By way of further example, symptoms of inflammatory bowel disease can include the following symptoms of Crohn's Disease or ulcerative colitis:
A. Symptoms of Crohn's disease can include:
B. The symptoms of ulcerative colitis may include:
The symptoms of multiple sclerosis and inflammatory bowel disease (including Crohn's Disease and ulcerative colitis) enumerated above, are merely illustrative and are not intended to be an exhaustive description of all possible symptoms experienced by a single patient or by several sufferers in composite, and to which the present invention is directed. Those skilled in the art are aware of various clinical symptoms and constellations of symptoms of autoimmune disorders suffered by individual patients, and to those symptoms are also directed the present inventive methods of treating an autoimmune disorder or of preventing or mitigating a relapse of a symptom of multiple sclerosis.
The therapeutically effective amount, prophylactically effective amount, and dosage regimen involved in the inventive methods of treating an autoimmune disorder or of preventing or mitigating a relapse of a symptom of multiple sclerosis, will be determined by the attending physician, considering various factors which modify the action of therapeutic agents, such as the age, condition, body weight, sex and diet of the patient, the severity of the condition being treated, time of administration, and other clinical factors. Generally, the daily amount or regimen should be in the range of about 1 to about 10,000 micrograms (ag) of the vehicle-conjugated peptide per kilogram (kg) of body mass, preferably about 1 to about 5000 μg per kilogram of body mass, and most preferably about 1 to about 1000 μg per kilogram of body mass.
Molecules of this invention incorporating peptide antagonists of the voltage-gated potassium channel Kv2.1 can be used to treat type II diabetes.
Molecules of this invention incorporating peptide antagonists of the M current (e.g., BeKm-1) can be used to treat Alzheimer's disease and enhance cognition.
Molecules of this invention incorporating peptide antagonists of the voltage-gated potassium channel Kv4.3 can be used to treat Alzheimer's disease.
Molecules of this invention incorporating peptide antagonists of the calcium-activated potassium channel of small conductance, SKCa can be used to treat epilepsy, memory, learning, neuropsychiatric, neurological, neuromuscular, and immunological disorders, schizophrenia, bipolar disorder, sleep apnea, neurodegeneration, and smooth muscle disorders.
Molecules of this invention incorporating N-type calcium channel antagonist peptides are useful in alleviating pain. Peptides with such activity (e.g., Ziconotide™, ω-conotoxin-MVIIA) have been clinically validated.
Molecules of this invention incorporating T-type calcium channel antagonist peptides are useful in alleviating pain. Several lines of evidence have converged to indicate that inhibition of Cav3.2 in dorsal root ganglia may bring relief from chronic pain. T-type calcium channels are found at extremely high levels in the cell bodies of a subset of neurons in the DRG; these are likely mechanoreceptors adapted to detect slowly-moving stimuli (Shin et al., Nature Neuroscience 6:724-730, 2003), and T-type channel activity is likely responsible for burst spiking (Nelson et al., J Neurosci 25:8766-8775, 2005). Inhibition of T-type channels by either mibefradil or ethosuximide reverses mechanical allodynia in animals induced by nerve injury (Dogrul et al., Pain 105:159-168, 2003) or by chemotherapy (Flatters and Bennett, Pain 109:150-161, 2004). Antisense to Cav3.2, but not Cav3.1 or Cav3.3, increases pain thresholds in animals and also reduces expression of Cav3.2 protein in the DRG (Bourinet et al., EMBO J 24:315-324, 2005). Similarly, locally injected reducing agents produce pain and increase Cav3.2 currents, oxidizing agents reduce pain and inhibit Cav3.2 currents, and peripherally administered neurosteroids are analgesic and inhibit T-type currents from DRG (Todorovic et al., Pain 109:328-339, 2004; Pathirathna et al., Pain 114:429-443, 2005). Accordingly, it is thought that inhibition of Cav3.2 in the cell bodies of DRG neurons can inhibit the repetitive spiking of these neurons associated with chronic pain states.
Molecules of this invention incorporating L-type calcium channel antagonist peptides are useful in treating hypertension. Small molecules with such activity (e.g., DHP) have been clinically validated.
Molecules of this invention incorporating peptide antagonists of the NaV1 (TTXs-type) channel can be used to alleviate pain. Local anesthetics and tricyclic antidepressants with such activity have been clinically validated. Such molecules of this invention can in particular be useful as muscle relaxants.
Molecules of this invention incorporating peptide antagonists of the NaV1 (TTXR-type) channel can be used to alleviate pain arising from nerve and or tissue injury.
Molecules of this invention incorporating peptide antagonists of glial & epithelial cell Ca2+-activated chloride channel can be used to treat cancer and diabetes.
Molecules of this invention incorporating peptide antagonists of NMDA receptors can be used to treat pain, epilepsy, brain and spinal cord injury.
Molecules of this invention incorporating peptide antagonists of nicotinic receptors can be used as muscle relaxants. Such molecules can be used to treat pain, gastric motility disorders, urinary incontinence, nicotine addiction, and mood disorders.
Molecules of this invention incorporating peptide antagonists of 5HT3 receptor can be used to treat Nausea, pain, and anxiety.
Molecules of this invention incorporating peptide antagonists of the norepinephrine transporter can be used to treat pain, anti-depressant, learning, memory, and urinary incontinence.
Molecules of this invention incorporating peptide antagonists of the Neurotensin receptor can be used to treat pain.
In addition to therapeutic uses, the compounds of the present invention can be useful in diagnosing diseases characterized by dysfunction of their associated protein of interest. In one embodiment, a method of detecting in a biological sample a protein of interest (e.g., a receptor) that is capable of being activated comprising the steps of: (a) contacting the sample with a compound of this invention; and (b) detecting activation of the protein of interest by the compound. The biological samples include tissue specimens, intact cells, or extracts thereof. The compounds of this invention can be used as part of a diagnostic kit to detect the presence of their associated proteins of interest in a biological sample. Such kits employ the compounds of the invention having an attached label to allow for detection. The compounds are useful for identifying normal or abnormal proteins of interest.
The therapeutic methods, compositions and compounds of the present invention can also be employed, alone or in combination with other molecules in the treatment of disease.
Pharmaceutical Compositions
In General. The present invention also provides pharmaceutical compositions comprising the inventive composition of matter and a pharmaceutically acceptable carrier. Such pharmaceutical compositions can be configured for administration to a patient by a wide variety of delivery routes, e.g., an intravascular delivery route such as by injection or infusion, subcutaneous, intramuscular, intraperitoneal, epidural, or intrathecal delivery routes, or for oral, enteral, pulmonary (e.g., inhalant), intranasal, transmucosal (e.g., sublingual administration), transdermal or other delivery routes and/or forms of administration known in the art. The inventive pharmaceutical compositions may be prepared in liquid form, or may be in dried powder form, such as lyophilized form. For oral or enteral use, the pharmaceutical compositions can be configured, for example, as tablets, troches, lozenges, aqueous or oily suspensions, dispersible powders or granules, emulsions, hard or soft capsules, syrups, elixirs or enteral formulas.
In the practice of this invention the “pharmaceutically acceptable carrier” is any physiologically tolerated substance known to those of ordinary skill in the art useful in formulating pharmaceutical compositions, including, any pharmaceutically acceptable diluents, excipients, dispersants, binders, fillers, glidants, anti-frictional agents, compression aids, tablet-disintegrating agents (disintegrants), suspending agents, lubricants, flavorants, odorants, sweeteners, permeation or penetration enhancers, preservatives, surfactants, solubilizers, emulsifiers, thickeners, adjuvants, dyes, coatings, encapsulating material(s), and/or other additives singly or in combination. Such pharmaceutical compositions can include diluents of various buffer content (e.g., Tris-HCl, acetate, phosphate), pH and ionic strength; additives such as detergents and solubilizing agents (e.g., Tween® 80, Polysorbate 80), anti-oxidants (e.g., ascorbic acid, sodium metabisulfite), preservatives (e.g., Thimersol®, benzyl alcohol) and bulking substances (e.g., lactose, mannitol); incorporation of the material into particulate preparations of polymeric compounds such as polylactic acid, polyglycolic acid, etc. or into liposomes. Hyaluronic acid can also be used, and this can have the effect of promoting sustained duration in the circulation. Such compositions can influence the physical state, stability, rate of in vivo release, and rate of in vivo clearance of the present proteins and derivatives. See, e.g., Remington's Pharmaceutical Sciences, 18th Ed. (1990, Mack Publishing Co., Easton, Pa. 18042) pages 1435-1712, which are herein incorporated by reference in their entirety. The compositions can be prepared in liquid form, or can be in dried powder, such as lyophilized form. Implantable sustained release formulations are also useful, as are transdermal or transmucosal formulations. Additionally (or alternatively), the present invention provides compositions for use in any of the various slow or sustained release formulations or microparticle formulations known to the skilled artisan, for example, sustained release microparticle formulations, which can be administered via pulmonary, intranasal, or subcutaneous delivery routes.
One can dilute the inventive compositions or increase the volume of the pharmaceutical compositions of the invention with an inert material. Such diluents can include carbohydrates, especially, mannitol, α-lactose, anhydrous lactose, cellulose, sucrose, modified dextrans and starch. Certain inorganic salts may also be used as fillers, including calcium triphosphate, magnesium carbonate and sodium chloride. Some commercially available diluents are Fast-Flo, Emdex, STA-Rx 1500, Emcompress and Avicell.
A variety of conventional thickeners are useful in creams, ointments, suppository and gel configurations of the pharmaceutical composition, such as, but not limited to, alginate, xanthan gum, or petrolatum, may also be employed in such configurations of the pharmaceutical composition of the present invention. A permeation or penetration enhancer, such as polyethylene glycol monolaurate, dimethyl sulfoxide, N-vinyl-2-pyrrolidone, N-(2-hydroxyethyl)-pyrrolidone, or 3-hydroxy-N-methyl-2-pyrrolidone can also be employed. Useful techniques for producing hydrogel matrices are known. (E.g., Feijen, Biodegradable hydrogel matrices for the controlled release of pharmacologically active agents, U.S. Pat. No. 4,925,677; Shah et al., Biodegradable pH/thermosensitive hydrogels for sustained delivery of biologically active agents, WO 00/38651 A1). Such biodegradable gel matrices can be formed, for example, by crosslinking a proteinaceous component and a polysaccharide or mucopolysaccharide component, then loading with the inventive composition of matter to be delivered.
Liquid pharmaceutical compositions of the present invention that are sterile solutions or suspensions can be administered to a patient by injection, for example, intramuscularly, intrathecally, epidurally, intravascularly (e.g., intravenously or intraarterially), intraperitoneally or subcutaneously. (See, e.g., Goldenberg et al., Suspensions for the sustained release of proteins, U.S. Pat. No. 6,245,740 and WO 00/38652 A1). Sterile solutions can also be administered by intravenous infusion. The inventive composition can be included in a sterile solid pharmaceutical composition, such as a lyophilized powder, which can be dissolved or suspended at a convenient time before administration to a patient using sterile water, saline, buffered saline or other appropriate sterile injectable medium.
Implantable sustained release formulations are also useful embodiments of the inventive pharmaceutical compositions. For example, the pharmaceutically acceptable carrier, being a biodegradable matrix implanted within the body or under the skin of a human or non-human vertebrate, can be a hydrogel similar to those described above. Alternatively, it may be formed from a poly-alpha-amino acid component. (Sidman, Biodegradable, implantable drug delivery device, and process for preparing and using same, U.S. Pat. No. 4,351,337). Other techniques for making implants for delivery of drugs are also known and useful in accordance with the present invention.
In powder forms, the pharmaceutically acceptable carrier is a finely divided solid, which is in admixture with finely divided active ingredient(s), including the inventive composition. For example, in some embodiments, a powder form is useful when the pharmaceutical composition is configured as an inhalant. (See, e.g., Zeng et al., Method of preparing dry powder inhalation compositions, WO 2004/017918; Trunk et al., Salts of the CGRP antagonist BIBN4096 and inhalable powdered medicaments containing them, U.S. Pat. No. 6,900,317).
One can dilute or increase the volume of the compound of the invention with an inert material. These diluents could include carbohydrates, especially mannitol, α-lactose, anhydrous lactose, cellulose, sucrose, modified dextrans and starch. Certain inorganic salts can also be used as fillers including calcium triphosphate, magnesium carbonate and sodium chloride. Some commercially available diluents are Fast-Flo™, Emdex™, STA-Rx™ 1500, Emcompress™ and Avicell™.
Disintegrants can be included in the formulation of the pharmaceutical composition into a solid dosage form. Materials used as disintegrants include but are not limited to starch including the commercial disintegrant based on starch, Explotab™. Sodium starch glycolate, Amberlite™, sodium carboxymethylcellulose, ultramylopectin, sodium alginate, gelatin, orange peel, acid carboxymethyl cellulose, natural sponge and bentonite can all be used. Insoluble cationic exchange resin is another form of disintegrant. Powdered gums can be used as disintegrants and as binders and these can include powdered gums such as agar, Karaya or tragacanth. Alginic acid and its sodium salt are also useful as disintegrants.
Binders can be used to hold the therapeutic agent together to form a hard tablet and include materials from natural products such as acacia, tragacanth, starch and gelatin. Others include methyl cellulose (MC), ethyl cellulose (EC) and carboxymethyl cellulose (CMC). Polyvinyl pyrrolidone (PVP) and hydroxypropylmethyl cellulose (HPMC) could both be used in alcoholic solutions to granulate the therapeutic.
An antifrictional agent can be included in the formulation of the therapeutic to prevent sticking during the formulation process. Lubricants can be used as a layer between the therapeutic and the die wall, and these can include but are not limited to; stearic acid including its magnesium and calcium salts, polytetrafluoroethylene (PTFE), liquid paraffin, vegetable oils and waxes. Soluble lubricants can also be used such as sodium lauryl sulfate, magnesium lauryl sulfate, polyethylene glycol of various molecular weights, Carbowax 4000 and 6000.
Glidants that might improve the flow properties of the drug during formulation and to aid rearrangement during compression might be added. The glidants can include starch, talc, pyrogenic silica and hydrated silicoaluminate.
To aid dissolution of the compound of this invention into the aqueous environment a surfactant might be added as a wetting agent. Surfactants can include anionic detergents such as sodium lauryl sulfate, dioctyl sodium sulfosuccinate and dioctyl sodium sulfonate. Cationic detergents might be used and could include benzalkonium chloride or benzethonium chloride. The list of potential nonionic detergents that could be included in the formulation as surfactants are lauromacrogol 400, polyoxyl 40 stearate, polyoxyethylene hydrogenated castor oil 10, 50 and 60, glycerol monostearate, polysorbate 40, 60, 65 and 80, sucrose fatty acid ester, methyl cellulose and carboxymethyl cellulose. These surfactants could be present in the formulation of the protein or derivative either alone or as a mixture in different ratios.
Oral dosage forms. Also useful are oral dosage forms of the inventive compositions. If necessary, the composition can be chemically modified so that oral delivery is efficacious. Generally, the chemical modification contemplated is the attachment of at least one moiety to the molecule itself, where said moiety permits (a) inhibition of proteolysis; and (b) uptake into the blood stream from the stomach or intestine. Also desired is the increase in overall stability of the compound and increase in circulation time in the body. Moieties useful as covalently attached half-life extending moieties in this invention can also be used for this purpose. Examples of such moieties include: PEG, copolymers of ethylene glycol and propylene glycol, carboxymethyl cellulose, dextran, polyvinyl alcohol, polyvinyl pyrrolidone and polyproline. See, for example, Abuchowski and Davis (1981), Soluble Polymer-Enzyme Adducts, Enzymes as Drugs (Hocenberg and Roberts, eds.), Wiley-Interscience, New York, N.Y., pp 367-83; Newmark, et al. (1982), J. Appl. Biochem. 4:185-9. Other polymers that could be used are poly-1,3-dioxolane and poly-1,3,6-tioxocane. Preferred for pharmaceutical usage, as indicated above, are PEG moieties.
For oral delivery dosage forms, it is also possible to use a salt of a modified aliphatic amino acid, such as sodium N-(8-[2-hydroxybenzoyl]amino) caprylate (SNAC), as a carrier to enhance absorption of the therapeutic compounds of this invention. The clinical efficacy of a heparin formulation using SNAC has been demonstrated in a Phase II trial conducted by Emisphere Technologies. See U.S. Pat. No. 5,792,451, “Oral drug delivery composition and methods.”
In one embodiment, the pharmaceutically acceptable carrier can be a liquid and the pharmaceutical composition is prepared in the form of a solution, suspension, emulsion, syrup, elixir or pressurized composition. The active ingredient(s) (e.g., the inventive composition of matter) can be dissolved, diluted or suspended in a pharmaceutically acceptable liquid carrier such as water, an organic solvent, a mixture of both, or pharmaceutically acceptable oils or fats. The liquid carrier can contain other suitable pharmaceutical additives such as detergents and/or solubilizers (e.g., Tween 80, Polysorbate 80), emulsifiers, buffers at appropriate pH (e.g., Tris-HCl, acetate, phosphate), adjuvants, anti-oxidants (e.g., ascorbic acid, sodium metabisulfite), preservatives (e.g., Thimersol, benzyl alcohol), sweeteners, flavoring agents, suspending agents, thickening agents, bulking substances (e.g., lactose, mannitol), colors, viscosity regulators, stabilizers, electrolytes, osmolutes or osmo-regulators. Additives can also be included in the formulation to enhance uptake of the inventive composition. Additives potentially having this property are for instance the fatty acids oleic acid, linoleic acid and linolenic acid.
Useful are oral solid dosage forms, which are described generally in Remington's Pharmaceutical Sciences (1990), supra, in Chapter 89, which is hereby incorporated by reference in its entirety. Solid dosage forms include tablets, capsules, pills, troches or lozenges, cachets or pellets. Also, liposomal or proteinoid encapsulation can be used to formulate the present compositions (as, for example, proteinoid microspheres reported in U.S. Pat. No. 4,925,673). Liposomal encapsulation can be used and the liposomes can be derivatized with various polymers (e.g., U.S. Pat. No. 5,013,556). A description of possible solid dosage forms for the therapeutic is given in Marshall, K., Modern Pharmaceutics (1979), edited by G. S. Banker and C. T. Rhodes, in Chapter 10, which is hereby incorporated by reference in its entirety. In general, the formulation will include the inventive compound, and inert ingredients that allow for protection against the stomach environment, and release of the biologically active material in the intestine.
The composition of this invention can be included in the formulation as fine multiparticulates in the form of granules or pellets of particle size about 1 mm. The formulation of the material for capsule administration could also be as a powder, lightly compressed plugs or even as tablets. The therapeutic could be prepared by compression.
Colorants and flavoring agents can all be included. For example, the protein (or derivative) can be formulated (such as by liposome or microsphere encapsulation) and then further contained within an edible product, such as a refrigerated beverage containing colorants and flavoring agents.
In tablet form, the active ingredient(s) are mixed with a pharmaceutically acceptable carrier having the necessary compression properties in suitable proportions and compacted in the shape and size desired.
The powders and tablets preferably contain up to 99% of the active ingredient(s). Suitable solid carriers include, for example, calcium phosphate, magnesium stearate, talc, sugars, lactose, dextrin, starch, gelatin, cellulose, polyvinylpyrrolidine, low melting waxes and ion exchange resins.
Controlled release formulation can be desirable. The composition of this invention could be incorporated into an inert matrix that permits release by either diffusion or leaching mechanisms e.g., gums. Slowly degenerating matrices can also be incorporated into the formulation, e.g., alginates, polysaccharides. Another form of a controlled release of the compositions of this invention is by a method based on the Oros™ therapeutic system (Alza Corp.), i.e., the drug is enclosed in a semipermeable membrane which allows water to enter and push drug out through a single small opening due to osmotic effects. Some enteric coatings also have a delayed release effect.
Other coatings can be used for the formulation. These include a variety of sugars that could be applied in a coating pan. The therapeutic agent could also be given in a film-coated tablet and the materials used in this instance are divided into 2 groups. The first are the nonenteric materials and include methylcellulose, ethyl cellulose, hydroxyethyl cellulose, methylhydroxy-ethyl cellulose, hydroxypropyl cellulose, hydroxypropyl-methyl cellulose, sodium carboxymethyl cellulose, providone and the polyethylene glycols. The second group consists of the enteric materials that are commonly esters of phthalic acid.
A mix of materials might be used to provide the optimum film coating. Film coating can be carried out in a pan coater or in a fluidized bed or by compression coating.
Pulmonarv delivery forms. Pulmonary delivery of the inventive compositions is also useful. The protein (or derivative) is delivered to the lungs of a mammal while inhaling and traverses across the lung epithelial lining to the blood stream. (Other reports of this include Adjei et al., Pharma. Res. (1990) 7: 565-9; Adjei et al. (1990), Internatl. J. Pharmaceutics 63: 135-44 (leuprolide acetate); Braquet et al. (1989), J. Cardiovasc. Pharmacol. 13 (supp1.5): s.143-146 (endothelin-1); Hubbard et al. (1989), Annals Int. Med. 3: 206-12 (α1-antitrypsin); Smith et al. (1989), J. Clin. Invest. 84: 1145-6 (α1-proteinase); Oswein et al. (March 1990), “Aerosolization of Proteins,” Proc. Symp. Resp. Drug Delivery II, Keystone, Colo. (recombinant human growth hormone); Debs et al. (1988), J. Immunol. 140: 3482-8 (interferon-γ and tumor necrosis factor α) and Platz et al., U.S. Pat. No. 5,284,656 (granulocyte colony stimulating factor).
Useful in the practice of this invention are a wide range of mechanical devices designed for pulmonary delivery of therapeutic products, including but not limited to nebulizers, metered dose inhalers, and powder inhalers, all of which are familiar to those skilled in the art. Some specific examples of commercially available devices suitable for the practice of this invention are the Ultravent nebulizer, manufactured by Mallinckrodt, Inc., St. Louis, Mo.; the Acorn II nebulizer, manufactured by Marquest Medical Products, Englewood, Colo.; the Ventolin metered dose inhaler, manufactured by Glaxo Inc., Research Triangle Park, N.C.; and the Spinhaler powder inhaler, manufactured by Fisons Corp., Bedford, Mass. (See, e.g., Helgesson et al., Inhalation device, U.S. Pat. No. 6,892,728; McDerment et al., Dry powder inhaler, WO 02/11801 A1; Ohki et al., Inhalant medicator, U.S. Pat. No. 6,273,086).
All such devices require the use of formulations suitable for the dispensing of the inventive compound. Typically, each formulation is specific to the type of device employed and can involve the use of an appropriate propellant material, in addition to diluents, adjuvants and/or carriers useful in therapy.
The inventive compound should most advantageously be prepared in particulate form with an average particle size of less than 10 μm (or microns), most preferably 0.5 to 5 μm, for most effective delivery to the distal lung.
Pharmaceutically acceptable carriers include carbohydrates such as trehalose, mannitol, xylitol, sucrose, lactose, and sorbitol. Other ingredients for use in formulations can include DPPC, DOPE, DSPC and DOPC. Natural or synthetic surfactants can be used. PEG can be used (even apart from its use in derivatizing the protein or analog). Dextrans, such as cyclodextran, can be used. Bile salts and other related enhancers can be used. Cellulose and cellulose derivatives can be used. Amino acids can be used, such as use in a buffer formulation.
Also, the use of liposomes, microcapsules or microspheres, inclusion complexes, or other types of carriers is contemplated.
Formulations suitable for use with a nebulizer, either jet or ultrasonic, will typically comprise the inventive compound dissolved in water at a concentration of about 0.1 to 25 mg of biologically active protein per mL of solution. The formulation can also include a buffer and a simple sugar (e.g., for protein stabilization and regulation of osmotic pressure). The nebulizer formulation can also contain a surfactant, to reduce or prevent surface induced aggregation of the protein caused by atomization of the solution in forming the aerosol.
Formulations for use with a metered-dose inhaler device will generally comprise a finely divided powder containing the inventive compound suspended in a propellant with the aid of a surfactant. The propellant can be any conventional material employed for this purpose, such as a chlorofluorocarbon, a hydrochlorofluorocarbon, a hydrofluorocarbon, or a hydrocarbon, including trichlorofluoromethane, dichlorodifluoromethane, dichlorotetrafluoroethanol, and 1,1,1,2-tetrafluoroethane, or combinations thereof. Suitable surfactants include sorbitan trioleate and soya lecithin. Oleic acid can also be useful as a surfactant. (See, e.g., Backström et al., Aerosol drug formulations containing hydrofluoroalkanes and alkyl saccharides, U.S. Pat. No. 6,932,962).
Formulations for dispensing from a powder inhaler device will comprise a finely divided dry powder containing the inventive compound and can also include a bulking agent, such as lactose, sorbitol, sucrose, mannitol, trehalose, or xylitol in amounts which facilitate dispersal of the powder from the device, e.g., 50 to 90% by weight of the formulation.
Nasal delivery forms. In accordance with the present invention, intranasal delivery of the inventive composition of matter and/or pharmaceutical compositions is also useful, which allows passage thereof to the blood stream directly after administration to the inside of the nose, without the necessity for deposition of the product in the lung. Formulations suitable for intransal administration include those with dextran or cyclodextran, and intranasal delivery devices are known. (See, e.g, Freezer, Inhaler, U.S. Pat. No. 4,083,368).
Transdermal and transmucosal (e.g., buccal) delivery forms). In some embodiments, the inventive composition is configured as a part of a pharmaceutically acceptable transdermal or transmucosal patch or a troche. Transdermal patch drug delivery systems, for example, matrix type transdermal patches, are known and useful for practicing some embodiments of the present pharmaceutical compositions. (E.g., Chien et al., Transdermal estrogen/progestin dosage unit, system and process, U.S. Pat. Nos. 4,906,169 and 5,023,084; Cleary et al., Diffusion matrix for transdermal drug administration and transdermal drug delivery devices including same, U.S. Pat. No. 4,911,916; Teillaud et al., EVA-based transdermal matrix system for the administration of an estrogen and/or a progestogen, U.S. Pat. No. 5,605,702; Venkateshwaran et al., Transdermal drug delivery matrix for coadministering estradiol and another steroid, U.S. Pat. No. 5,783,208; Ebert et al., Methods for providing testosterone and optionally estrogen replacement therapy to women, U.S. Pat. No. 5,460,820). A variety of pharmaceutically acceptable systems for transmucosal delivery of therapeutic agents are also known in the art and are compatible with the practice of the present invention. (E.g., Heiber et al., Transmucosal delivery of macromolecular drugs, U.S. Pat. Nos. 5,346,701 and 5,516,523; Longenecker et al., Transmembrane formulations for drug administration, U.S. Pat. No. 4,994,439).
Buccal delivery of the inventive compositions is also useful. Buccal delivery formulations are known in the art for use with peptides. For example, known tablet or patch systems configured for drug delivery through the oral mucosa (e.g., sublingual mucosa), include some embodiments that comprise an inner layer containing the drug, a permeation enhancer, such as a bile salt or fusidate, and a hydrophilic polymer, such as hydroxypropyl cellulose, hydroxypropyl methylcellulose, hydroxyethyl cellulose, dextran, pectin, polyvinyl pyrrolidone, starch, gelatin, or any number of other polymers known to be useful for this purpose. This inner layer can have one surface adapted to contact and adhere to the moist mucosal tissue of the oral cavity and can have an opposing surface adhering to an overlying non-adhesive inert layer. Optionally, such a transmucosal delivery system can be in the form of a bilayer tablet, in which the inner layer also contains additional binding agents, flavoring agents, or fillers. Some useful systems employ a non-ionic detergent along with a permeation enhancer. Transmucosal delivery devices may be in free form, such as a cream, gel, or ointment, or may comprise a determinate form such as a tablet, patch or troche. For example, delivery of the inventive composition can be via a transmucosal delivery system comprising a laminated composite of, for example, an adhesive layer, a backing layer, a permeable membrane defining a reservoir containing the inventive composition, a peel seal disc underlying the membrane, one or more heat seals, and a removable release liner. (E.g., Ebert et al., Transdermal delivery system with adhesive overlay and peel seal disc, U.S. Pat. No. 5,662,925; Chang et al., Device for administering an active agent to the skin or mucosa, U.S. Pat. Nos. 4,849,224 and 4,983,395). These examples are merely illustrative of available transmucosal drug delivery technology and are not limiting of the present invention.
Dosages. The dosage regimen involved in a method for treating the above-described conditions will be determined by the attending physician, considering various factors which modify the action of drugs, e.g. the age, condition, body weight, sex and diet of the patient, the severity of any infection, time of administration and other clinical factors. Generally, the daily regimen should be in the range of 0.1-1000 micrograms of the inventive compound per kilogram of body weight, preferably 0.1-150 micrograms per kilogram.
The compositions described above can be prepared as described below. These examples are not to be construed in any way as limiting the scope of the present invention.
Fc-L10-ShK[1-35], also referred to as “Fc-2xL-ShK[1-35]”, an inhibitor of Kv1.3. A DNA sequence coding for the Fc region of human IgG1 fused in-frame to a linker sequence and a monomer of the Kv1.3 inhibitor peptide ShK[1-35] was constructed as described below. Methods for expressing and purifying the peptibody from mammalian cells (HEK 293 and Chinese Hamster Ovary cells) are disclosed herein.
The expression vector pcDNA3.1(+) CMVi (
The Fc-L10-ShK[1-35] expression vector was constructing using PCR stategies to generate the full length ShK gene linked to a four glycine and one serine amino acid linker (lower case letters here indicate linker sequence of L-form amino acid residues) with two stop codons and flanked by BamHI and NotI restriction sites as shown below.
GGATCCGGAGGAGGAGGAAGCCGCAGCTGCATCGACACCATCCCCAAGAGCCGCTGCACCGCCTTCCAG
Two oligos with the sequence as depicted below were used in a PCR reaction with Herculase™ polymerase (Stratagene) at 94° C.-30 sec, 50° C.-30 sec, and 72° C.-1 min for 30 cycles.
The resulting PCR products were resolved as the 150 bp bands on a one percent agarose gel. The 150 bp PCR product was digested with BamHI and NotI (Roche) restriction enzymes and agarose gel purified by Gel Purification Kit (Qiagen). At the same time, the pcDNA3.1 (+) CMVi-hFc-ActivinRIIB vector (
HEK-293 cells used in transient transfection expression of Fc-2xL-ShK[1-35] in pcDNA3.1(+) CMVi protein were cultured in growth medium containing DMEM High Glucose (Gibco), 10% fetal bovine serum (FBS from Gibco) and 1× non-essential amino acid (NEAA from Gibco). 5.6 ug of Fc-2xL-ShK[1-35] in pcDNA3.1(+) CMVi plasmid that had been phenol/chloroform extracted was transfected into HEK-293 cells using Fugene 6 (Roche). The cells recovered for 24 hours, and then placed in DMEM High Glucose and 1×NEAA medium for 48 hours. The conditioned medium was concentrated 50× by running 30 ml through Centriprep YM-10 filter (Amicon) and further concentrated by a Centricon YM-10 (Amicon) filter. Various amounts of concentrated medium were mixed with an in-house 4× Loading Buffer (without B-mercaptoethanol) and electrophoresed on a Novex 4-20% tris-glycine gel using a Novex Xcell II apparatus at 101V/46 mA for 2 hours in a 5× Tank buffer solution (0.123 Tris Base, 0.96M Glycine) along with 10 ul of BenchMark Pre-Stained Protein ladder (Invitrogen). The gel was then soaked in Electroblot buffer (35 mM Tris base, 20% methanol, 192 mM glycine) for 30 minutes. A PVDF membrane from Novex (Cat. No. LC2002, 0.2 um pores size) was soaked in methanol for 30 seconds to activate the PVDF, rinsed with deionized water, and soaked in Electroblot buffer. The pre-soaked gel was blotted to the PVDF membrane using the XCell II Blot module according to the manufacturer instructions (Novex) at 40 mA for 2 hours. Then, the blot was first soaked in a 5% milk (Carnation) in Tris buffered saline solution pH7.5 (TBS) for 1 hour at room temperature and incubated with 1:500 dilution in TBS with 0.1% Tween-20 (TBST Sigma) and 1% milk buffer of the HRP-conjugated murine anti-human Fc antibody (Zymed Laboratores Cat. no. 05-3320) for two hours shaking at room temperature. The blot was then washed three times in TBST for 15 minutes per wash at room temperature. The primary antibody was detected using Amersham Pharmacia Biotech's ECL western blotting detection reagents according to manufacturer's instructions. Upon ECL detection, the western blot analysis displayed the expected size of 66 kDa under non-reducing gel conditions (
AM1 CHOd- (Amgen Proprietary) cells used in the stable expression of Fc-L10-ShK[1-35] protein were cultured in AM1 CHOd- growth medium containing DMEM High Glucose, 10% fetal bovine serum, 1× hypoxantine/thymidine (HT from Gibco) and 1×NEAA. 6.5 ug of pcDNA3.1(+) CMVi-Fc-ShK plasmid was also transfected into AM1 CHOd- cells using Fugene 6. The following day, the transfected cells were plated into twenty 15 cm dishes and selected using DMEM high glucose, 10% FBS, 1×HT, 1×NEAA and Geneticin (800 μg/ml G418 from Gibco) for thirteen days. Forty-eight surviving colonies were picked into two 24-well plates. The plates were allowed to grow up for a week and then replicated for freezing. One set of each plate was transferred to AM1 CHOd- growth medium without 10% FBS for 48 hours and the conditioned media were harvested. Western Blot analysis similar to the transient Western blot analysis with detection by the same anti-human Fc antibody was used to screen 15 ul of conditioned medium for expressing stable CHO clones. Of the 48 stable clones, more than 50% gave ShK expression at the expected size of 66 kDa. The BB6, BD5 and BD6 clones were selected with BD5 and BD6 as a backup to the primary clone BB6 (
The BB6 clone was scaled up into ten roller bottles (Corning) using AM1 CHOd- growth medium and grown to confluency as judged under the microscope. Then, the medium was exchanged with a serum-free medium containing to 50% DMEM high glucose and 50% Ham's F12 (Gibco) with 1×HT and 1×NEAA and let incubate for one week. The conditioned medium was harvested at the one-week incubation time, filtered through 0.45 μm filter (Corning) and frozen. Fresh serum-free medium was added and incubated for an additional week. The conditioned serum-free medium was harvested like the first time and frozen.
Purification of monovalent and bivalent dimeric Fc-L10-ShK(1-35). Approximately 4 L of conditioned medium was thawed in a water bath at room temperature. The medium was concentrated to about 450 ml using a Satorius Sartocon Polysulfon 10 tangential flow ultra-filtration cassette (0.1 m2) at room temperature. The retentate was then filtered through a 0.22 μm cellulose acetate filter with a pre-filter. The retentate was then loaded on to a 5 ml Amersham HiTrap Protein A column at 5 ml/min 7° C., and the column was washed with several column volumes of Dulbecco's phosphate buffered saline without divalent cations (PBS) and sample was eluted with a step to 100 mM glycine pH 3.0. The protein A elution pool (approximately 9 ml) was diluted to 50 ml with water and loaded on to a 5 ml Amersham HiTrap SP-HP column in S-Buffer A (20 mM NaH2PO4, pH 7.0) at 5 ml/min and 7° C. The column was then washed with several column volumes S-Buffer A, and then developed using a linear gradient from 25% to 75% S-Buffer B (20 mM NaH2PO4, 1 M NaCl, pH 7.0) at 5 ml/min followed by a step to 100% S-Buffer B at 7° C. Fractions were then analyzed using a Coomassie brilliant blue stained tris-glycine 4-20% SDS-PAGE, and the fractions containing the desired product were pooled based on these data. The pooled material was then concentrated to about 3.4 ml using a Pall Life Sciences Macrosep 10K Omega centrifugal ultra-filtration device and then filtered though a Costar 0.22 μm cellulose acetate syringe filter.
A spectral scan was then conducted on 10 μl of the filtered material diluted in 700111 PBS using a Hewlett Packard 8453 spectrophotometer (
The purity of the filtered bivalent dimeric Fc-L10-ShK(1-35) product was assessed using a Coomassie brilliant blue stained tris-glycine 4-20% SDS-PAGE (
Purified bivalent dimeric Fc-L10-ShK[1-35] potently blocked human Kv1.3 (
A DNA sequence coding for the Fc region of human IgG1 fused in-frame to a monomer of the Kv1.3 inhibitor peptide ShK[2-35] was constructed using standard PCR technology. The ShK[2-35] and the 5, 10, or 25 amino acid linker portion of the molecule were generated in a PCR reaction using the original Fc-2xL-ShK[1-35] in pcDNA3.1(+) CMVi as a template (Example 1,
with the first amino acid of the wild-type sequence deleted.
The sequences of the primers used to generate Fc-L5-ShK[2-35], also referred to as “Fc-1xL-ShK[2-35]”, are shown below:
The sequences of the primers used to generate Fc-L10-ShK[2-35], also referred to as “Fc-2xL-ShK[2-35]” are shown below:
The sequences of the primers used to generate Fc-L25-ShK[2-35], also referred to as “Fc-5xL-ShK[2-35]”, are shown below:
The PCR products were digested with BamHI and NotI (Roche) restriction enzymes and agarose gel purified by Gel Purification Kit. At the same time, the pcDNA3.1(+) CMVi-hFc-ActivinRIIB vector was digested with BamHI and NotI restriction enzymes and the large fragment was purified by Gel Purification Kit. Each purified PCR product was ligated to the large fragment and transformed into XL-1 blue bacteria. DNAs from transformed bacterial colonies were isolated and subjected to BamHI and NotI restriction enzyme digestions and resolved on a one percent agarose gel. DNAs resulting in an expected pattern were submitted for sequencing. Although, analysis of several sequences of clones yielded a 100% percent match with the above sequence, only one clone was selected for large scaled plasmid purification. The DNA from this clone was resequenced to confirm the Fc and linker regions and the sequence was 100% identical to the expected sequence.
Plasmids containing the Fc-1xL-Shk[2-35], Fc-2xL-Shk[2-35] and Fc-5xL-Shk[2-35] inserts in pcDNA3.1 (+) CMVi vector were digested with Xba1 and Xho1 (Roche) restriction enzymes and gel purified. The inserts were individually ligated into Not1 and SalI (Roche) digested pDSRα-22 (Amgen Proprietary) expression vector. Integrity of the resulting constructs were confirmed by DNA sequencing. The final plasmid DNA expression vector constructs were pDSRα-22-Fc-1xL-Shk[2-35], pDSRα-22-Fc-2xL-Shk[2-35] (
Twenty-four hours prior to transfection, 1.2e7 AM-1/D CHOd- (Amgen Proprietary) cells were plated into a T-175 cm sterile tissue culture flask, to allow 70-80% confluency on the day of transfection. The cells had been maintained in the AM-1/D CHOd- culture medium containing DMEM High Glucose, 5% FBS, 1× Glutamine Pen/Strep (Gibco), 1×HT, 1×NEAA's and 1× sodium pyruvate (Gibco). The following day, eighteen micrograms of each of the linearized pDSRα22:Fc-1xL-ShK[2-35], pDSRα22:Fc-2xL-ShK[2-35] and pDSRα22:Fc-5xL-ShK[2-35] (RDS's #20050037685, 20050053709, 20050073295) plasmids were mixed with 72 μg of linearized Selexis MAR plasmid and pPAGO1 (RDS 20042009896) and diluted into 6 ml of OptiMEM in a 50 ml conical tube and incubate for five minutes. LF2000 (210 μl) was added to 6 ml of OptiMEM and incubated for five minutes. The diluted DNA and LF2000 were mixed together and incubated for 20 minutes at room temperature. In the meantime, the cells were washed one time with PBS and then 30 ml OptiMEM without antibiotics were added to the cells. The OptiMEM was aspirated off, and the cells were incubated with 12 ml of DNA/LF2000 mixture for 6 hours or overnight in the 37° C. incubator with shaking. Twenty-four hours post transfection, the cells were split 1:5 into AM-1/D CHOd- culture medium and at differing dilutions for colony selection. Seventy-two hours post transfection, the cell medium was replaced with DHFR selection medium containing 10% Dialyzed FBS (Gibco) in DMEM High Glucose, plus 1× Glutamine Pen/Strep, 1×NEAA's and 1× Na Pyr to allow expression and secretion of protein into the cell medium. The selection medium was changed two times a week until the colonies are big enough to pick. The pDSRa22 expression vector contains a DHFR expression cassette, which allows transfected cells to grow in the absence of hypoxanthine and thymidine. The five T-175 pools of the resulting colonies were scaled up into roller bottles and cultured under serum free conditions. The conditioned media were harvested and replaced at one-week intervals. The resulting 3 liters of conditioned medium was filtered through a 0.45 μm cellulose acetate filter (Corning, Acton, Mass.) and transferred to Protein Chemistry for purification. As a backup, twelve colonies were selected from the 10 cm plates after 10-14 days on DHFR selection medium and expression levels evaluated by western blot using HRP conjugated anti human IgGFc as a probe. The three best clones expressing the highest level of each of the different linker length Fc-L-ShK[2-35] fusion proteins were expanded and frozen for future use.
Purification of Fc-L10-ShK(2-35). Approximately 1 L of conditioned medium was thawed in a water bath at room temperature. The medium was loaded on to a 5 ml Amersham HiTrap Protein A column at 5 ml/min 7° C., and the column was washed with several column volumes of Dulbecco's phosphate buffered saline without divalent cations (PBS) and sample was eluted with a step to 100 mM glycine pH 3.0. The protein A elution pool (approximately 8.5 ml) combined with 71 μl 3 M sodium acetate and then diluted to 50 ml with water. The diluted material was then loaded on to a 5 ml Amersham HiTrap SP-HP column in S-Buffer A (20 mM NaH2PO4, pH 7.0) at 5 ml/min 7° C. The column was then washed with several column volumes S-Buffer A, and then developed using a linear gradient from 0% to 75% S-Buffer B (20 mM NaH2PO4, 1 M NaCl, pH 7.0) at 5 ml/min followed by a step to 100% S-Buffer B at 7° C. Fractions were then analyzed using a Coomassie brilliant blue stained tris-glycine 4-20% SDS-PAGE, and the fractions containing the desired product were pooled based on these data. The pooled material was then filtered through a 0.22 μm cellulose acetate filter and concentrated to about 3.9 ml using a Pall Life Sciences Macrosep 10K Omega centrifugal ultra-filtration device. The concentrated material was then filtered though a Pall Life Sciences Acrodisc with a 0.22 μm, 25 mm Mustang E membrane at 2 ml/min room temperature. A spectral scan was then conducted on 10 μl of the filtered material diluted in 700 μl PBS using a Hewlett Packard 8453 spectrophotometer (
A spectral scan was then conducted on 10 μl of the combined pool diluted in 700 μl PBS using a Hewlett Packard 8453 spectrophotometer. The concentration of the filtered material was determined to be 3.33 mg/ml using a calculated molecular mass of 30,008 g/mol and extinction coefficient of 36,900 M−1 cm−1. The purity of the filtered material was then assessed using a Coomassie brilliant blue stained tris-glycine 4-20% SDS-PAGE (
Purification of Fc-L5-ShK(2-35). Approximately 1 L of conditioned medium was loaded on to a 5 ml Amersham HiTrap Protein A column at 5 ml/min 7° C., and the column was washed with several column volumes of Dulbecco's phosphate buffered saline without divalent cations (PBS) and sample was eluted with a step to 100 mM glycine pH 3.0. The protein A elution pool (approximately 9 ml) combined with 450 μl 1 M tris HCl pH 8.5 followed by 230 μl 2 M acetic acid then diluted to 50 ml with water. The pH adjusted material was then filtered through a 0.22 μm cellulose acetate filter and loaded on to a 5 ml Amersham HiTrap SP-HP column in S-Buffer A (20 mM NaH2PO4, pH 7.0) at 5 ml/min 7° C. The column was then washed with several column volumes S-Buffer A, and then developed using a linear gradient from 0% to 75% S-Buffer B (20 mM NaH2PO4, 1 M NaCl, pH 7.0) at 5 ml/min followed by a step to 100% S-Buffer B at 7° C. Fractions were then analyzed using a Coomassie brilliant blue stained tris-glycine 4-20% SDS-PAGE, and the fractions containing the desired product were pooled based on these data. The pooled material was then concentrated to about 5.5 ml using a Pall Life Sciences Macrosep 10K Omega centrifugal ultra-filtration device. The concentrated material was then filtered though a Pall Life Sciences Acrodisc with a 0.22 μm, 25 mm Mustang E membrane at 2 ml/min room temperature.
A spectral scan was then conducted on 10 μl of the combined pool diluted in 700111 PBS using a Hewlett Packard 8453 spectrophotometer (
Purification of Fc-L25-ShK(2-35). Approximately 1 L of conditioned medium was loaded on to a 5 ml Amersham HiTrap Protein A column at 5 ml/min 7° C., and the column was washed with several column volumes of Dulbecco's phosphate buffered saline without divalent cations (PBS) and sample was eluted with a step to 100 mM glycine pH 3.0. The protein A elution pool (approximately 9.5 ml) combined with 119 μl 3 M sodium acetate and then diluted to 50 ml with water. The pH adjusted material was then loaded on to a 5 ml Amersham HiTrap SP-HP column in S-Buffer A (20 mM NaH2PO4, pH 7.0) at 5 ml/min 7° C. The column was then washed with several column volumes S-Buffer A, and then developed using a linear gradient from 0% to 75% S-Buffer B (20 mM NaH2PO4, 1 M NaCl, pH 7.0) at 5 ml/min followed by a step to 100% S-Buffer B at 7° C. Fractions containing the main peak from the chromatogram were pooled and filtered through a 0.22 μm cellulose acetate filter.
A spectral scan was then conducted on 20 μl of the combined pool diluted in 700111 PBS using a Hewlett Packard 8453 spectrophotometer
Purified Fc-L25-ShK[2-35] inhibited human Kv1.3 with an IC50 of ˜150 pM by whole cell patch clamp electrophysiology on HEK293/Kv1.3 cells (Example 36).
Description of bacterial peptibody expression vectors and procedures for cloning and expression of peptibodies. The cloning vector used for bacterial expression (Examples 3-30) is based on pAMG21 (originally described in U.S. Patent 2004/0044188). It has been modified in that the kanamycin resistance component has been replaced with ampicillin resistance by excising the DNA between the unique BstBI and NsiI sites of the vector and replacing with an appropriately digested PCR fragment bearing the beta-lactamase gene using PCR primers CCA ACA CAC TTC GAA AGA CGT TGA TCG GCA C (SEQ ID NO: 667) and CAC CCA ACA ATG CAT CCT TAA AAA AAT TAC GCC C (SEQ ID NO: 668) with pUC19 DNA as the template source of the beta-lactamase gene conferring resistance to ampicillin. The new version is called pAMG21ampR.
Description of cloning vector pAMG21ampR-Fc-Pep used in examples 3 to 30, excluding 15 and 16.
A second BsmBI site occurs at nucleotides 6643 through 6648; viz., CGTCTC. DNA cleavage occurs between nucleotides 6650 and 6651 on the upper strand and between 6654 and 6655 on the lower strand.
CGTCTCT
GCAGAGAATTC
Between the two BsmBI sites is a dispensable chloramphenicol resistance cassette constitutively expressing chloramphenicol acetyltransferase (cat gene). The cat protein sequence:
is shown in
Description of the cloning vector pAMG21ampR-Pep-Fc used in examples 15 and 16.
Digestion creates 4 bp cohesive termini as shown. The BsmBI site is underlined.
A second BsmBI site occurs at nucleotides 5607 through 5612; viz., CGTCTC. Cutting occurs between nucleotides 5613 and 5614 on the upper strand and between 5617 and 5618 on the lower strand.
CGTCTCA
GCAGAGTCCAC
Between the BsmBI sites is a dispensable zeocin resistance cassette constitutively expressing the Shigella ble protein. The ble protein sequence:
is shown extending from nucleotides 5217 to 5588 in
Description of the cloning vector DAMG21ampR-Pep-Fc used in Examples 52 and 53.
Digestion creates 4 bp cohesive termini as shown. The BsmBI site is underlined.
A second BsmBI site occurs at nucleotides 5607 through 5612; viz., CGTCTC. Cutting occurs between nucleotides 5613 and 5614 on the upper strand and between 5617 and 5618 on the lower strand.
CGTCTCA GGTGGTGGT
GCAGAGTCCAC CACCA
Between the BsmBI sites is a dispensable zeocin resistance cassette constitutively expressing the Shigella ble protein. The ble protein sequence, as described above, is shown extending from nucleotide positions 5220 to 5591. The peptide encoding duplexes in Examples 52 and 53 herein below bear cohesive ends complementary to those presented by the vector.
For Examples 3 to 30 for which all are for bacterial expression, cloned peptide sequences are all derived from the annealing of oligonucleotides to create a DNA duplex that is directly ligated into the appropriate vector. Two oligos suffice for Example 20, four are required for all other examples. When the duplex is to be inserted at the N-terminus of Fc (see, Examples 15, 16, 52, and 53 herein) the design is as follows with the ordinal numbers matching the listing of oligos in each example:
When the duplex is to be inserted at the C-terminus of Fc (Examples 3, 4, 5, 10, 11, 12, 13, and 30) the design is as follows:
All remaining examples have the duplex inserted at the C-terminus of Fc and utilize the following design.
No kinasing step is required for the phosphorylation of any of the oligos. A successful insertion of a duplex results in the replacement of the dispensable antibiotic resistance cassette (Zeocin resistance for pAMG21ampR-Pep-Fc and chloramphenicol resistance for pAMG21ampR-Fc-Pep). The resulting change in phenotype is useful for discriminating recombinant from nonrecombinant clones.
The following description gives the uniform method for carrying out the cloning of all 30 bacterially expressed recombinant proteins exemplified herein. Only the set of oligonucleotides and the vector are varied. These specifications are given below in each example.
An oligonucleotide duplex containing the coding region for a given peptide was formed by annealing the oligonucleotides listed in each example. Ten picomoles of each oligo was mixed in a final volume of 10 μl containing 1× ligation buffer along with 0.3 μg of appropriate vector that had been previously digested with restriction endonuclease BsmBI. The mix was heated to 80° C. and allowed to cool at 0.1 degree/sec to room temperature. To this was added 10 μl of 1× ligase buffer plus 400 units of T4 DNA ligase. The sample was incubated at 14 C for 20 min. Ligase was inactivated by heating at 65° C. for 10 minutes. Next, 10 units of restriction endonucleases BsmBI were added followed by incubation at 55 C for one hour to cleave any reformed parental vector molecules. Fifty ul of chemically competent E. coli cells were added and held at 2 C for 20 minutes followed by heat shock at 42 C for 5 second. The entire volume was spread onto Luria Agar plates supplemented with carbenicillin at 200 μg/ml and incubated overnight at 37 C. Colonies were tested for the loss of resistance to the replaceable antibiotic resistance marker. A standard PCR test can be used to confirm the expected size of the duplex insert. Plasmid preparations were obtained and the recombinant insert was verified by DNA sequencing. Half liter cultures of a sequence confirmed construct were grown in Terrific Broth, expression of the peptibody was induced by addition of N-(3-oxo-hexanoyl)-homoserine lactone at 50 ng/ml and after 4-6 hours of shaking at 37 C the cells were centrifuged and the cell paste stored at −20 C.
The following gives for each example the cloning vector and the set of oligonucleotides used for constructing each fusion protein. Also shown is a DNA/protein map.
Bacterial expression of Fc-L-ShK[1-35] inhibitor of Kv1.3. The methods to clone and express the peptibody in bacteria are described above. The vector used was pAMG21ampR-Fc-Pep and the oligos listed below were used to generate a duplex (see below) for cloning and expression in bacteria of Fc-L-ShK[1-35].
Oligos used to form the duplex:
The oligo duplex is shown below:
Bacterial expression of the peptibody was as described in Example 3 and paste was stored frozen. Purification of bacterially expressed Fc-L10-ShK(1-35) is further described in Example 38 herein below.
Bacterial expression of Fc-L-ShK[2-35]. The methods to clone and express the peptibody in bacteria are described in Example 3. The vector used was pAMG21ampR-Fc-Pep and the oligos listed below were used to generate a duplex (see below) for cloning and expression in bacteria of Fc-L-ShK[2-35].
Oligos used to form duplex are shown below:
The oligo duplex formed is shown below:
Bacterial expression of the peptibody was as described in Example 3 and paste was stored frozen. Purification of bacterially expressed Fc-L10-ShK(2-35) is further described in Example 39 herein below.
Bacterial expression of Fc-L-HmK. The methods to clone and express the peptibody in bacteria are described in Example 3. The vector used was pAMG21ampR-Fc-Pep and the oligos listed below were used to generate a duplex (see below) for cloning and expression in bacteria of Fc-L-HmK.
Oligos used to form duplex are shown below:
The oligo duplex formed is shown below:
Bacterial expression of the peptibody was as described in Example 3 and paste was stored frozen.
Bacterial expression of Fc-L-KTX1. The methods to clone and express the peptibody in bacteria are described in Example 3. The vector used was pAMG21ampR-Fc-Pep and the oligos listed below were used to generate a duplex (see below) for cloning and expression in bacteria of Fc-L-KTX1.
Oligos used to form duplex are shown below:
The oligo duplex formed is shown below:
Bacterial expression of the peptibody was as described in Example 3 and paste was stored frozen.
Purification and refolding of Fc-L-KTX1 expressed in bacteria. Frozen, E. coli paste (28 g) was combined with 210 ml of room temperature 50 mM tris HCl, 5 mM EDTA, pH 8.0 and was brought to about 0.1 mg/ml hen egg white lysozyme. The suspended paste was passed through a chilled microfluidizer twice at 12,000 PSI. The cell lysate was then centrifuged at 22,000 g for 20 min at 4° C. The pellet was then resuspended in 200 ml 1% deoxycholic acid using a tissue grinder and then centrifuged at 22,000 g for 20 min at 4° C. The pellet was then resuspended in 200 ml water using a tissue grinder and then centrifuged at 22,000 g for 20 min at 4° C. The pellet (4.8 g) was then dissolved in 48 ml 8 M guanidine HCl, 50 mM tris HCl, pH 8.0. The dissolved pellet was then reduced by adding 30 μl 1 M dithiothreitol to 3 ml of the solution and incubating at 37° C. for 30 minutes. The reduced pellet solution was then centrifuged at 14,000 g for 5 min at room temperature, and then 2.5 ml of the supernatant was transferred to 250 ml of the refolding buffer (2 M urea, 50 mM tris, 160 mM arginine HCl, 5 mM EDTA, 1 mM cystamine HCl, 4 mM cysteine, pH 8.5) at 4° C. with vigorous stirring. The stirring rate was then slowed and the incubation was continued for 2 days at 4° C. The refolding solution was then filtered through a 0.22 μm cellulose acetate filter and stored at 4° C. for 3 days.
The stored refold was then diluted with 1 L of water and the pH was adjusted to 7.5 using 1 M H3PO4. The pH adjusted material was then loaded on to a 10 ml Amersham SP-HP HiTrap column at 10 ml/min in S-Buffer A (20 mM NaH2PO4, pH 7.3) at 7° C. The column was then washed with several column volumes of S-Buffer A, followed by elution with a linear gradient from 0% to 60% S-Buffer B (20 mM NaH2PO4, 1 M NaCl, pH 7.3) followed by a step to 100% S-Buffer B at 5 ml/min 7° C. Fractions were then analyzed using a Coomassie brilliant blue stained tris-glycine 4-20% SDS-PAGE, and the fractions containing the desired product were pooled based on these data (45 ml). The pool was then loaded on to a 1 ml Amersham rProtein A HiTrap column in PBS at 2 ml/min 7° C. Then column was then washed with several column volumes of PBS and eluted with 100 mM glycine pH 3.0. To the elution peak (2.5 ml), 62.5 μl 2 M tris base was added, and then the pH adjusted material was filtered though a Pall Life Sciences Acrodisc with a 0.22 μm, 25 mm Mustang E membrane at 2 ml/min room temperature.
A spectral scan was then conducted on 20 μl of the combined pool diluted in 700 μl PBS using a Hewlett Packard 8453 spectrophotometer (
Purified Fc-L-KTX1 blocked the human Kv1.3 current in a dose-dependent fashion (
Bacterial expression of Fc-L-HsT1. The methods to clone and express the peptibody in bacteria are described in Example 3. The vector used was pAMG21ampR-Fc-Pep and the oligos listed below were used to generate a duplex (see below) for cloning and expression in bacteria of Fc-L-HsTx1.
Oligos used to form duplex are shown below:
The duplex formed by the oligos above is shown below:
Bacterial expression of the peptibody was as described in Example 3 and paste was stored frozen.
Bacterial expression of Fc-L-MgTx. The methods to clone and express the peptibody in bacteria are described in Example 3. The vector used was pAMG21ampR-Fc-Pep and the oligos listed below were used to generate a duplex (see below) for cloning and expression in bacteria of Fc-L-MgTx.
Oligos used to form duplex are shown below:
The oligos above were used to form the duplex shown below:
Bacterial expression of the peptibody was as described in Example 3 and paste was stored frozen.
Bacterial expression of Fc-L-AgTx2. The methods to clone and express the peptibody in bacteria are described in Example 3. The vector used was pAMG21ampR-Fc-Pep and the oligos listed below were used to generate a duplex (see below) for cloning and expression in bacteria of Fc-L-AgTx2.
Oligos used to form duplex are shown below:
The oligos listed above were used to form the duplex shown below:
Bacterial expression of the peptibody was as described in Example 3 and paste was stored frozen.
Refolding and purification of Fc-L-AgTx2 expressed in bacteria. Frozen, E. coli paste (15 g) was combined with 120 ml of room temperature 50 mM tris HCl, 5 mM EDTA, pH 8.0 and was brought to about 0.1 mg/ml hen egg white lysozyme. The suspended paste was passed through a chilled microfluidizer twice at 12,000 PSI. The cell lysate was then centrifuged at 22,000 g for 20 min at 4° C. The pellet was then resuspended in 200 ml 1% deoxycholic acid using a tissue grinder and then centrifuged at 22,000 g for 20 min at 4° C. The pellet was then resuspended in 200 ml water using a tissue grinder and then centrifuged at 22,000 g for 20 min at 4° C. The pellet (4.6 g) was then dissolved in 46 ml 8 M guanidine HCl, 50 mM tris HCl, pH 8.0. The dissolved pellet was then reduced by adding 30 μl 1 M dithiothreitol to 3 ml of the solution and incubating at 37° C. for 30 minutes. The reduced pellet solution was then centrifuged at 14,000 g for 5 min at room temperature, and then 2.5 ml of the supernatant was transferred to 250 ml of the refolding buffer (2 M urea, 50 mM tris, 160 mM arginine HCl, 5 mM EDTA, 1 mM cystamine HCl, 4 mM cysteine, pH 9.5) at 4° C. with vigorous stirring. The stirring rate was then slowed and the incubation was continued for 2 days at 4° C. The refolding solution was then filtered through a 0.22 μm cellulose acetate filter and stored at −70° C.
The stored refold was defrosted and then diluted with 1 L of water and the pH was adjusted to 7.5 using 1 M H3PO4. The pH adjusted material was then filtered through a 0.22 μm cellulose acetate filter and loaded on to a 10 ml Amersham SP-HP HiTrap column at 10 ml/min in S-Buffer A (20 mM NaH2PO4, pH 7.3) at 7° C. The column was then washed with several column volumes of S-Buffer A, followed by elution with a linear gradient from 0% to 60% S-Buffer B (20 mM NaH2PO4, 1 M NaCl, pH 7.3) followed by a step to 100% S-Buffer B at 5 ml/min 7° C. Fractions were then analyzed using a Coomassie brilliant blue stained tris-glycine 4-20% SDS-PAGE, and the fractions containing the desired product were pooled based on these data (15 ml). The pool was then loaded on to a 1 ml Amersham rProtein A HiTrap column in PBS at 2 ml/min 7° C. Then column was then washed with several column volumes of 20 mM NaH2PO4 pH 6.5, 1 M NaCl and eluted with 100 mM glycine pH 3.0. To the elution peak (1.5 ml), 70 μl 1 M tris HCl pH 8.5 was added, and then the pH-adjusted material was filtered though a 0.22 μm cellulose acetate filter.
A spectral scan was then conducted on 20 μl of the combined pool diluted in 700 μl PBS using a Hewlett Packard 8453 spectrophotometer (
Bacterial expression of Fc-L-OSK1. The methods used to clone and express the peptibody in bacteria were as described in Example 3. The vector used was pAMG21ampR-Fc-Pep and the oligos listed below were used to generate a duplex (see below) for cloning and expression in bacteria of Fc-L-OSK1.
Oligos used to form duplex are shown below:
The oligos shown above were used to form the duplex below:
Bacterial expression of the peptibody was as described in Example 3 and paste was stored frozen for later use. Purification of Fc-L10-OSK1 from E. coli paste is described in Example 40 herein below.
Bacterial expression of Fc-L-OSK1(E16K, K20D). The methods to clone and express the peptibody in bacteria are described in Example 3. The vector used was pAMG21ampR-Fc-Pep the oligos listed below were used to generate a duplex (see below) for cloning and expression in bacteria of Fc-L-OSK1(E16K,K20D).
Oligos used to form duplex are shown below:
The oligos shown above were used to form the duplex below:
Bacterial expression of the peptibody was as described in Example 3 and paste was stored frozen for later use.
Bacterial expression of Fc-L-Anuroctoxin. The methods to clone and express the peptibody in bacteria are described in Example 3. The vector used was pAMG21ampR-Fc-Pep and the oligos listed below were used to generate a duplex (see below) for cloning and expression in bacteria of Fc-L-Anuroctoxin.
Oligos used to form duplex are shown below:
The oligos shown above were used to form the duplex below:
Bacterial expression of the peptibody was as described in Example 3 and paste was stored frozen.
Bacterial expression of Fc-L-Noxiustoxin or Fc-L-NTX. The methods to clone and express the peptibody in bacteria are described in Example 3. The vector used was pAMG21ampR-Fc-Pep and the oligos listed below were used to generate a duplex (see below) for cloning and expression in bacteria of Fc-L-NTX.
Oligos used to form duplex are shown below:
The oligos shown above were used to form the duplex below:
Bacterial expression of the peptibody was as described in Example 3 and paste was stored frozen.
Bacterial expression of Fc-L-Pi2. The methods to clone and express the peptibody in bacteria are described in Example 3. The vector used was pAMG21ampR-Fc-Pep and the oligos listed below were used to generate a duplex (see below) for cloning and expression in bacteria of Fc-L-Pi2.
Oligos used to form duplex are shown below:
The oligos above were used to form the duplex below:
Bacterial expression of the peptibody was as described in Example 3 and paste was stored frozen.
Bacterial expression of ShK[1-35]-L-Fc. The methods to clone and express the peptibody in bacteria are described in Example 3. The vector used was pAMG21ampR-Pep-Fc and the oligos listed below were used to generate a duplex (see below) for cloning and expression in bacteria of ShK[1-35]-L-Fc.
Oligos used to form duplex are shown below:
The oligos shown above were used to form the duplex shown below:
Bacterial expression of the peptibody was as described in Example 3 and paste was stored frozen. Purification of met-ShK[1-35]-Fc was as described in Example 51 herein below.
Bacterial expression of ShK[2-35]-L-Fc. The methods to clone and express the peptibody in bacteria are described in Example 3. The vector used was pAMG21ampR-Pep-Fc and the oligos listed below were used to generate a duplex (see below) for cloning and expression in bacteria of ShK[2-35]-L-Fc.
Oligos used to form duplex are shown below:
The oligos above were used to form the duplex shown below:
Bacterial expression of the peptibody was as described in Example 3 and paste was stored frozen. Purification of the ShK[2-35]-Fc was as described in Example 50 herein below.
Bacterial expression of Fc-L-ChTx. The methods to clone and express the peptibody in bacteria are described in Example 3. The vector used was pAMG21ampR-Fc-Pep and the oligos listed below were used to generate a duplex (see below) for cloning and expression in bacteria of Fc-L-ChTx.
Oligos used to form duplex are shown below:
Bacterial expression of the peptibody was as described in Example 3 and paste was stored frozen.
Bacterial expression of Fc-L-MTX. The methods to clone and express the peptibody in bacteria are described in Example 3. The vector used was pAMG21ampR-Fc-Pep and the oligos listed below were used to generate a duplex (see below) for cloning and expression in bacteria of Fc-L-MTX.
Oligos used to form duplex are shown below:
The oligos above were used to form the duplex shown below:
Bacterial expression of the peptibody was as described in Example 3 and paste was stored frozen.
Bacterial expression of Fc-L-ChTx (K32E). The methods to clone and express the peptibody in bacteria are described in Example 3. The vector used was pAMG21ampR-Fc-Pep and the oligos listed below were used to generate a duplex (see below) for cloning and expression in bacteria of Fc-L-ChTx (K32E).
Oligos used to form duplex are shown below:
The oligos shown above were used to form the duplex below:
Bacterial expression of the peptibody was as described in Example 3 and paste was stored frozen.
Bacterial expression of Fc-L-Apamin. The methods to clone and express the peptibody in bacteria are described in Example 3. The vector used was pAMG21ampR-Fc-Pep and the oligos listed below were used to generate a duplex (see below) for cloning and expression in bacteria of Fc-L-Apamin.
Oligos used to form duplex are shown below:
The oligos above were used to form the duplex shown below:
Bacterial expression of the peptibody was as described in Example 3 and paste was stored frozen.
Bacterial expression of Fc-L-Scyllatoxin or Fc-L-ScyTx. The methods to clone and express the peptibody in bacteria are described in Example 3. The vector used was pAMG21ampR-Fc-Pep and the oligos listed below were used to generate a duplex (see below) for cloning and expression in bacteria of Fc-L-ScyTx.
Oligos used to form duplex are shown below:
The oligos above were used to form the duplex below:
Bacterial expression of the peptibody was as described in Example 3 and paste was stored frozen.
Bacterial expression of Fc-L-lbTx. The methods to clone and express the peptibody in bacteria are described in Example 3. The vector used was pAMG21ampR-Fc-Pep and the oligos listed below were used to generate a duplex (see below) for cloning and expression in bacteria of Fc-L-lbTx.
Oligos used to form duplex are shown below:
The oligos above were used to form the duplex below:
Bacterial expression of the peptibody was as described in Example 3 and paste was stored frozen.
Bacterial expression of Fc-L-HaTx1. The methods to clone and express the peptibody in bacteria are described in Example 3. The vector used was pAMG21ampR-Fc-Pep and the oligos listed below were used to generate a duplex (see below) for cloning and expression in bacteria of Fc-L-HaTx1.
Oligos used to form duplex are shown below:
The oligos above were used to form the duplex below:
Bacterial expression of the peptibody was as described in Example 3 and paste was stored frozen.
Refolding and purification of Fc-L-HaTx1 expressed in bacteria. Frozen, E. coli paste (13 g) was combined with 100 ml of room temperature 50 mM tris HCl, 5 mM EDTA, pH 8.0 and was brought to about 0.1 mg/ml hen egg white lysozyme. The suspended paste was passed through a chilled microfluidizer twice at 12,000 PSI. The cell lysate was then centrifuged at 22,000 g for 20 min at 4° C. The pellet was then resuspended in 200 ml 1% deoxycholic acid using a tissue grinder and then centrifuged at 22,000 g for 20 min at 4° C. The pellet was then resuspended in 200 ml water using a tissue grinder and then centrifuged at 22,000 g for 20 min at 4° C. The pellet (2.6 g) was then dissolved in 26 ml 8 M guanidine HCl, 50 mM tris HCl, pH 8.0. The dissolved pellet was then reduced by adding 30 μl 1 M dithiothreitol to 3 ml of the solution and incubating at 37° C. for 30 minutes. The reduced pellet solution was then centrifuged at 14,000 g for 5 min at room temperature, and then 2.5 ml of the supernatant was transferred to 250 ml of the refolding buffer (2 M urea, 50 mM tris, 160 mM arginine HCl, 5 mM EDTA, 1 mM cystamine HCl, 4 mM cysteine, pH 8.5) at 4° C. with vigorous stirring. The stirring rate was then slowed and the incubation was continued for 2 days at 4° C. The refolding solution was then filtered through a 0.22 μm cellulose acetate filter and stored at −70° C.
The stored refold was defrosted and then diluted with 1 L of water and the pH was adjusted to 7.5 using 1 M H3PO4. The pH adjusted material was then filtered through a 0.22 μm cellulose acetate filter and loaded on to a 10 ml Amersham SP-HP HiTrap column at 10 ml/min in S-Buffer A (20 mM NaH2PO4, pH 7.3) at 7° C. The column was then washed with several column volumes of S-Buffer A, followed by elution with a linear gradient from 0% to 60% S-Buffer B (20 mM NaH2PO4, 1 M NaCl, pH 7.3) followed by a step to 100% S-Buffer B at 5 ml/min 7° C. Fractions were then analyzed using a Coomassie brilliant blue stained tris-glycine 4-20% SDS-PAGE, and the fractions containing the desired product were pooled based on these data (15 ml). The pool was then loaded on to a 1 ml Amersham rProtein A HiTrap column in PBS at 2 ml/min 7° C. Then column was then washed with several column volumes of 20 mM NaH2PO4 pH 6.5, 1 M NaCl and eluted with 100 mM glycine pH 3.0. To the elution peak (1.4 ml), 70 μl 1 M tris HCl pH 8.5 was added, and then the pH adjusted material was filtered though a 0.22 μm cellulose acetate filter.
A spectral scan was then conducted on 20 μl of the combined pool diluted in 700 μl PBS using a Hewlett Packard 8453 spectrophotometer (
Bacterial expression of Fc-L-PaTx2. The methods to clone and express the peptibody in bacteria are described in Example 3. The vector used was pAMG21ampR-Fc-Pep and the oligos listed below were used to generate a duplex (see below) for cloning and expression in bacteria of Fc-L-PaTx2.
Oligos used to form duplex are shown below:
The oligos above were used to form the duplex below:
Bacterial expression of the peptibody was as described in Example 3 and paste was stored frozen.
Bacterial expression of Fc-L-wGVIA. The methods to clone and express the peptibody in bacteria are described in Example 3. The vector used was pAMG21ampR-Fc-Pep and the oligos listed below were used to generate a duplex (see below) for cloning and expression in bacteria of Fc-L-wGVIA.
Oligos used to form duplex are shown below:
The oligos above were used to form the duplex below:
Bacterial expression of the peptibody was as described in Example 3 and paste was stored frozen.
Bacterial expression of Fc-L-ωMVIIA. The methods to clone and express the peptibody in bacteria are described in Example 3. The vector used was pAMG21ampR-Fc-Pep and the oligos listed below were used to generate a duplex (see below) for cloning and expression in bacteria of Fc-L-ωMVIIA.
Oligos used to form duplex are shown below:
The oligos above were used to form the duplex below:
Bacterial expression of the peptibody was as described in Example 3 and paste was stored frozen.
Bacterial expression of Fc-L-Ptu1. The methods to clone and express the peptibody in bacteria are described in Example 3. The vector used was pAMG21ampR-Fc-Pep and the oligos listed below were used to generate a duplex (see below) for cloning and expression in bacteria of Fc-L-Ptu1.
Oligos used to form duplex are shown below:
The oligos above were used to form the duplex below:
Bacterial expression of the peptibody was as described in Example 3 and paste was stored frozen.
Bacterial expression of Fc-L-ProTx1. The methods to clone and express the peptibody in bacteria are described in Example 3. The vector used was pAMG21ampR-Fc-Pep and the oligos listed below were used to generate a duplex (see below) for cloning and expression in bacteria of Fc-L-ProTx1.
Oligos used to form duplex are shown below:
The oligos above were used to form the duplex below:
Bacterial expression of the peptibody was as described in Example 3 and paste was stored frozen.
Bacterial expression of Fc-L-BeKM1. The methods to clone and express the peptibody in bacteria are described in Example 3. The vector used was pAMG21ampR-Fc-Pep and the oligos listed below were used to generate a duplex (see below) for cloning and expression in bacteria of Fc-L-BeKM1.
Oligos used to form duplex are shown below:
The oligos above were used to form the duplex below:
Bacterial expression of the peptibody was as described in Example 3 and paste was stored frozen.
Bacterial expression of Fc-L-CTX. The methods to clone and express the peptibody in bacteria are described in Example 3. The vector used was pAMG21ampR-Fc-Pep and the oligos listed below were used to generate a duplex (see below) for cloning and expression in bacteria of Fc-L-CTX.
Oligos used to form duplex are shown below:
The oligos above were used to form the duplex below:
Bacterial expression of the peptibody was as described in Example 3 and paste was stored frozen.
Peptide Synthesis of reduced Des-Arq1-ShK. Des-Arg1-ShK, having the sequence
was synthesized in a stepwise manner on a Symphony™ multi-peptide synthesizer by solid-phase peptide synthesis (SPPS) using 2-(1H-benzotriazole-1-yl)-1,1,3,3-tetramethyluronium hexafluorophosphate (HBTU)/N-methyl morpholine (NMM)/N,N-dimethyl-formamide (DMF) coupling chemistry at 0.1 mmol equivalent resin scale on Tentagel™-S PHB Fmoc-Cys(Trt)-resin. N-alpha-(9-fluorenylmethyloxycarbonyl)- and side-chain protected amino acids were purchased from Midwest Biotech Incorporated. Fmoc-Cys(Trt)-Tentagel™ resin was purchased from Fluka. The following side-chain protection strategy was employed: Asp(OtBu), Arg(Pbf), Cys(Trt), Gln(Trt), His(Trt), Lys(Nε-Boc), Ser(OtBu), Thr(OtBu) and Tyr(OtBu). Two Oxazolidine dipeptides, Fmoc-Gly-Thr(ψMe,MePro)-OH and Fmoc-Leu-Ser(ψMe,MePro)-OH, were used in the chain assembly and were obtained from NovaBiochem and used in the synthesis of the sequence. The protected amino acid derivatives (20 mmol) were dissolved in 100 ml 20% dimethyl sulfoxide (DMSO) in DMF (v/v). Protected amino acids were activated with 20 mM HBTU, 400 mM NMM in 20% DMSO in DMF, and coupling were carried out using two treatments with 0.5 mmol protected amino acid, 0.5 mmol HBTU, 1 mmol NMM in 20% DMF/DMSO for 25 minutes and then 40 minutes. Fmoc deprotection reactions were carried out with two treatments using a 20% piperidine in DMF (v/v) solution for 10 minutes and then 15 minutes. Following synthesis, the resin was then drained, and washed with DCM, DMF, DCM, and then dried in vacuo. The peptide-resin was deprotected and released from the resin by treatment with a TFA/EDT/TIS/H2O (92.5:2.5:2.5:2.5 (v/v)) solution at room temperature for 1 hour. The volatiles were then removed with a stream of nitrogen gas, the crude peptide precipitated twice with cold diethyl ether and collected by centrifugation. The crude peptide was then analyzed on a Waters 2795 analytical RP-HPLC system using a linear gradient (0-60% buffer B in 12 minutes, A: 0.1% TFA in water, B: 0.1% TFA in acetonitrile) on a Jupiter 4 μm Proteo™ 90 Å column. A PE-Sciex™ API Electro-spray mass spectrometer was used to confirm correct peptide product mass. Crude peptide was obtained in 143 mg yield at approximately 70% pure based as estimated by analytical RP-HPLC analysis. Reduced Des-Arg1-ShK (Peptide 1) Retention time (Rt)=5.31 minutes, calculated molecular weight=3904.6917 Da (average); Experimental observed molecular weight 3907.0 Da.
Folding of Des-Arq1-ShK (Disulphide bond formation). Following TFA cleavage and peptide precipitation, reduced Des-Arg1-ShK was then air-oxidized to give the folded peptide. The crude cleaved peptide was extracted using 20% AcOH in water (v/v) and then diluted with water to a concentration of approximately 0.15 mg reduced Des-Arg1-ShK per mL, the pH adjusted to about 8.0 using NH4OH (28-30%), and gently stirred at room temperature for 36 hours. Folding process was monitored by LC-MS analysis. Following this, folded Des-Arg1-ShK peptide was purified using reversed phase HPLC using a 1 Luna 5 μm C18 100 Å Proteo™ column with a linear gradient 0-40% buffer B in 120 min (A=0.1% TFA in water, B=0.1% TFA in acetonitrile). Folded Des-Arg1-ShK crude peptide eluted earlier (when compared to the elution time in its reduced form) at approximately 25% buffer B. Folded Des-Arg1-ShK (Peptide 2) was obtained in 23.2 mg yield in >97% purity as estimated by analytical RP-HPLC analysis (
N-terminal PEGylation of Folded Des-Arq1-ShK. Folded Des-Arg1-ShK, (Peptide 2) was dissolved in water at 1 mg/ml concentration. A 2 M MeO-PEG-Aldehyde, CH3O—[CH2CH2O]n-CH2CH2CHO (average molecular weight 20 kDa), solution in 50 mM NaOAc, pH 4.5, and a separate 1 M solution of NaCNBH3 were freshly prepared. The peptide solution was then added to the MeO-PEG-Aldehyde containing solution and was followed by the addition of the NaCNBH3 solution. The reaction stoichiometry was peptide:PEG:NaCNBH3 (1:2:0.02), respectively. The reaction was left for 48 hours, and was analyzed on an Agilent 1100 RP-HPLC system using Zorbax™ 300SB-C8 5 μm column at 40° C. with a linear gradient (6-60% B in 16 minutes, A: 0.1% TFA in water, B: 0.1% TFA/90% ACN in water). Mono-pegylated folded Des-Arg1-ShK constituted approximately 58% of the crude product by analytical RP-HPLC. Mono Pegylated Des-Arg1-ShK was then isolated using a HiTrap™ 5 ml SP HP cation exchange column on AKTA FPLC system at 4° C. at 1 mL/min using a gradient of 0-50% B in 25 column volumes (Buffers: A=20 mM sodium acetate pH 4.0, B=1 M NaCl, 20 mM sodium acetate, pH 4.0). The fractions were analyzed using a 4-20 tris-Gly SDS-PAGE gel and RP-HPLC (as described for the crude). SDS-PAGE gels were run for 1.5 hours at 125 V, 35 mA, 5 W. Pooled product was then dialyzed at 4° C. in 3 changes of 1 L of A4S buffer (10 mM NaOAc, 5% sorbitol, pH 4.0). The dialyzed product was then concentrated in 10 K microcentrifuge filter to 2 mL volume and sterile-filtered using 0.2 μM syringe filter to give the final product. N-Terminally PEGylated-Des-Arg1-ShK (Peptide 3) was isolated in 1.7 mg yield with 85% purity as estimated by analytical RP-HPLC analysis (
The N-Terminally PEGylated-Des-Arg1-ShK, also referred to as “PEG-ShK[2-35]”, was active in blocking human Kv1.3 (
The experimental procedures of this working example correspond to the results shown in
Peptide Synthesis of reduced ShK. ShK, having the amino acid sequence
was synthesized in a stepwise manner on a Symphony™ multi-peptide synthesizer by solid-phase peptide synthesis (SPPS) using 2-(1H-benzotriazole-1-yl)-1,1,3,3-tetramethyluronium hexafluorophosphate (HBTU)/N-methyl morpholine (NMM)/N,N-dimethyl-formamide (DMF) coupling chemistry at 0.1 mmol equivalent resin scale on Tentagel™-S PHB Fmoc-Cys(Trt)-resin. N-alpha-9-fluorenylmethyloxycarbonyl) and side-chain protected amino acids were purchased from Midwest Biotech Incorporated. Fmoc-Cys(Trt)-Tentagel™ resin was purchased from Fluka. The following side-chain protection strategy was employed: Asp(OtBu), Arg(Pbf), Cys(Trt), Gln(Trt), His(Trt), Lys(Nε-Boc), Ser(OtBu), Thr(OtBu) and Tyr(OtBu). Two Oxazolidine dipeptides, Fmoc-Gly-Thr(ψMe,MePro)-OH and Fmoc-Leu-Ser(ψMe,MePro)-OH, were used in the chain assembly and were obtained from NovaBiochem and used in the synthesis of the sequence. The protected amino acid derivatives (20 mmol) were dissolved in 100 ml 20% dimethyl sulfoxide (DMSO) in DMF (v/v). Protected amino acids were activated with 200 mM HBTU, 400 mM NMM in 20% DMSO in DMF, and coupling were carried out using two treatments with 0.5 mmol protected amino acid, 0.5 mmol HBTU, 1 mmol NMM in 20% DMF/DMSO for 25 minutes and then 40 minutes. Fmoc deprotections were carried out with two treatments using a 20% piperidine in DMF (v/v) solution for 10 minutes and then 15 minutes. Following synthesis, the resin was then drained, and washed with DCM, DMF, DCM, and then dried in vacuo. The peptide-resin was deprotected and released from the resin by treatment with a TFA/EDT/TIS/H2O (92.5:2.5:2.5:2.5 (v/v)) solution at room temperature for 1 hour. The volatiles were then removed with a stream of nitrogen gas, the crude peptide precipitated twice with cold diethyl ether and collected by centrifugation. The crude peptide was then analyzed on a Waters 2795 analytical RP-HPLC system using a linear gradient (0-60% buffer B in 12 minutes, A: 0.1% TFA in water, B: 0.1% TFA in acetonitrile) on a Jupiter 4 μm Proteo™ 90 Å column. A PE-Sciex API Electro-spray mass spectrometer was used to confirm correct peptide product mass. Crude peptide was approximately was obtained 170 mg yield at about 45% purity as estimated by analytical RP-HPLC analysis. Reduced ShK (Peptide 4) Retention time (Rt)=5.054 minutes, calculated molecular weight=4060.8793 Da (average); experimental observed molecular weight=4063.0 Da.
Folding of ShK (Disulphide bond formation). Following TFA cleavage and peptide precipitation, reduced ShK was then air oxidized to give the folded peptide. The crude cleaved peptide was extracted using 20% AcOH in water (v/v) and then diluted with water to a concentration of approximately 0.15 mg reduced ShK per mL, the pH adjusted to about 8.0 using NH4OH (28-30%), and gently stirred at room temperature for 36 hours. Folding process was monitored by LC-MS analysis. Following this, folded ShK peptide was purified by reversed phase HPLC using a 1″ Luna 5 μm C18 100 Å Proteo™ column with a linear gradient 0-40% buffer B in 120 min (A=0.1% TFA in water, B=0.1% TFA in acetonitrile). Folded ShK crude peptide eluted earlier (when compared to the elution time in its reduced form) at approximately 25% buffer B. Folded ShK (Peptide 5) was obtained in 25.5 mg yield in >97% purity as estimated by analytical RP-HPLC analysis. See
N-terminal PEGylation of Folded ShK. Folded ShK, having the amino acid sequence
can be dissolved in water at 1 mg/ml concentration. A 2 M MeO-PEG-Aldehyde, CH3O—CH2CH2O]n-CH2CH2CHO (average molecular weight 20 kDa), solution in 50 mM NaOAc, pH 4.5 and a separate 1 M solution of NaCNBH3 can be freshly prepared. The peptide solution can be then added to the MeO-PEG-Aldehyde containing solution and can be followed by the addition of the NaCNBH3 solution. The reaction stoichiometry can be peptide:PEG:NaCNBH3 (1:2:0.02), respectively. The reaction can be left for 48 hours, and can be analyzed on an Agilent™ 1100 RP-HPLC system using Zorbax™ 300SB-C8 5 μm column at 40° C. with a linear gradient (6-60% B in 16 minutes, A: 0.1% TFA in water, B: 0.1% TFA/90% ACN in water). Mono-pegylated Shk (Peptide 6) can be then isolated using a HiTrap™ 5 mL SP HP cation exchange column on AKTA FPLC system at 4° C. at 1 mL/min using a gradient of 0-50% B in 25 column volumes (Buffers: A=20 mM sodium acetate pH 4.0, B=1 M NaCl, 20 mM sodium acetate, pH 4.0). The fractions can be analyzed using a 4-20 tris-Gly SDS-PAGE gel and RP-HPLC. SDS-PAGE gels can be run for 1.5 hours at 125 V, 35 mA, 5 W. Pooled product can be then dialyzed at 4° C. in 3 changes of 1 L of A4S buffer (10 mM sodium acetate, 5% sorbitol, pH 4.0). The dialyzed product can be then concentrated in 10 K microcentrifuge filter to 2 mL volume and sterile-filtered using 0.2 μM syringe filter to give the final product.
Peptide Synthesis of reduced ShK. ShK, having the sequence
can be synthesized in a stepwise manner on a Symphony™ multi-peptide synthesizer by solid-phase peptide synthesis (SPPS) using 2-(1H-benzotriazole-1-yl)-1,1,3,3-tetramethyluronium hexafluorophosphate (HBTU)/N-methyl morpholine (NMM)/N,N-dimethyl-formamide (DMF) coupling chemistry at 0.1 mmol equivalent resin scale on Tentagel™-S PHB Fmoc-Cys(Trt)-resin. N-alpha-(9-fluorenylmethyloxycarbonyl)- and side-chain protected amino acids can be purchased from Midwest Biotech Incorporated. Fmoc-Cys(Trt)-Tentagel™ resin can be purchased from Fluka. The following side-chain protection strategy can be employed: Asp(OtBu), Arg(Pbf), Cys(Trt), Gln(Trt), His(Trt), Lys(Nε-Boc), Ser(OtBu), Thr(OtBu) and Tyr(OtBu). Two Oxazolidine dipeptides, Fmoc-Gly-Thr(ΨMe,MePro)-OH and Fmoc-Leu-Ser(ψMe,MePro)-OH, can be used in the chain assembly and can be obtained from NovaBiochem and used in the synthesis of the sequence. The protected amino acid derivatives (20 mmol) can be dissolved in 100 ml 20% dimethyl sulfoxide (DMSO) in DMF (v/v). Protected amino acids can be activated with 200 mM HBTU, 400 mM NMM in 20% DMSO in DMF, and coupling can be carried out using two treatments with 0.5 mmol protected amino acid, 0.5 mmol HBTU, 1 mmol NMM in 20% DMF/DMSO for 25 minutes and then 40 minutes. Fmoc deprotection reactions can be carried out with two treatments using a 20% piperidine in DMF (v/v) solution for 10 minutes and then 15 minutes. Following the chain-assembly of the Shk peptide, Boc-amionooxyacetic acid (1.2 equiv) can be coupled at the N-terminus using 0.5 M HBTU in DMF with 4 equiv collidine for 5 minutes. Following synthesis, the resin can be then drained, and washed with DCM, DMF, DCM, and then dried in vacuo. The peptide-resin can be deprotected and released from the resin by treatment with a TFA/amionooxyacetic acid/TIS/EDT/H2O (90:2.5:2.5:2.5:2.5) solution at room temperature for 1 hour. The volatiles can be then removed with a stream of nitrogen gas, the crude peptide precipitated twice with cold diethyl ether and collected by centrifugation. The aminooxy-Shk peptide (Peptide 7) can be then analyzed on a Waters 2795 analytical RP-HPLC system using a linear gradient (0-60% buffer B in 12 minutes, A: 0.1% TFA in water also containing 0.1% aminooxyacetic acid, B: 0.1% TFA in acetonitrile) on a Jupiter 4 μm Proteo™ 90 Å column.
Reversed-Phase HPLC Purification. Preparative Reversed-phase high-performance liquid chromatography can be performed on C18, 5 μm, 2.2 cm×25 cm) column. Chromatographic separations can be achieved using linear gradients of buffer B in A (A=0.1% aqueous TFA; B=90% aq. ACN containing 0.09% TFA and 0.1% aminooxyacetic acid), typically 5-95% over 90 minutes at 15 mL/min. Preparative HPLC fractions can be characterized by ESMS and photodiode array (PDA) HPLC, combined and lyophilized.
N-Terminal PEGylation of Shk by Oxime Formation. Lyophilized aminooxy-Shk (Peptide 7) can be dissolved in 50% HPLC buffer A/B (5 mg/mL) and added to a two-fold molar excess of MeO-PEG-Aldehyde, CH3O—[CH2CH2O]n—CH2CH2CHO (average molecular weight 20 kDa). The reaction can be left for 24 hours, and can be analyzed on an Agilent™ 1100 RP-HPLC system using Zorbax™ 300SB-C8 5 μm column at 40° C. with a linear gradient (6-60% B in 16 minutes, A: 0.1% TFA in water, B: 0.1% TFA/90% ACN in water). Mono-pegylated reduced Shk constituted approximately 58% of the crude product by analytical RP-HPLC. Mono PEGylated (oximated) Shk (Peptide 8) can be then isolated using a HiTrap™ 5 mL SP HP cation exchange column on AKTA FPLC system at 4° C. at 1 mL/min using a gradient of 0-50% B in 25 column volumes (Buffers: A 20 mM sodium acetate pH 4.0, B=1 M NaCl, 20 mM sodium acetate, pH 4.0). The fractions can be analyzed using a 4-20 tris-Gly SDS-PAGE gel and RP-HPLC. SDS-PAGE gels can be run for 1.5 hours at 125 V, 35 mA, 5 W. Pooled product can be then dialyzed at 4° C. in 3 changes of 1 L of A4S buffer (10 mM NaOAc, 5% sorbitol, pH 4.0). The dialyzed product can be then concentrated in 10 K microcentrifuge filter to 2 mL volume and sterile-filtered using 0.2 μM syringe filter to give the final product.
Folding of ShK (Disulphide bond formation). The mono-PEGylated (oximated) Shk can be dissolved in 20% AcOH in water (v/v) and can be then diluted with water to a concentration of approximately 0.15 mg peptide mL, the pH adjusted to about 8.0 using NH4OH (28-30%), and gently stirred at room temperature for 36 hours. Folding process can be monitored by LC-MS analysis. Following this, folded mono-PEGylated (oximated) Shk (Peptide 9) can be purified using by reversed phase HPLC using a 1′ Luna 5 μm C18 100 Å Proteo™ column with a linear gradient 0-40% buffer B in 120 min (A=0.1% TFA in water, B=0.1% TFA in acetonitrile). Mono-PEGylated (oximated) ShK disulfide connectivity can be C1-C6, C2-C4, and C3-C5.
The experimental procedures of this working example correspond to the results shown in
N-Terminal PEGylation of Shk by Amide Formation. A 10 mg/mL solution of folded Shk (Peptide 5), in 100 mM Bicine pH 8.0, can be added to solid succinimidyl ester of 20 kDa PEG propionic acid (mPEG-SPA; CH3O—[CH2CH2O]n-CH2CH2CO—NHS) at room temperature using a 1.5 molar excess of the mPEG-SPA to Shk. After one hour with gentle stirring, the mixture can be diluted to 2 mg/mL with water, and the pH can be adjusted to 4.0 with dilute HCl. The extent of mono-pegylated Shk (Peptide 10), some di-PEGylated Shk or tri-PEGylated Shk, unmodified Shk and succinimidyl ester hydrolysis can be determined by SEC HPLC using a Superdex™ 75 HR 10/30 column (Amersham) eluted with 0.05 M NaH2PO4, 0.05 M Na2HPO4, 0.15 M NaCl, 0.01 M NaN3, pH 6.8, at 1 mL/min. The fractions can be analyzed using a 4-20 tris-Gly SDS-PAGE gel and RP-HPLC. SDS-PAGE gels can be run for 1.5 hours at 125 V, 35 mA, 5 W. Pooled product can be then dialyzed at 4° C. in 3 changes of 1 L of A4S buffer (10 mM NaOAc, 5% sorbitol, pH 4.0). The dialyzed N-terminally PEGylated (amidated) ShK (Peptide 10) can be then concentrated in 10 K microcentrifuge filter to 2 mL volume and sterile-filtered using 0.2 μM syringe filter to give the final product.
Fc-SmIIIA expression vector. A 104 bp BamHI-NotI fragment containing partial linker sequence and SmIIIA peptide encoded with human high frequency codons was assembled by PCR with overlapping primers 3654-50 and 3654-51 and cloned into to the 7.1 kb NotI-BamHI back bone to generate pcDNA3.1(+) CMVi-hFc-SmIIIA as described in Example 1.
The sequences of the BamHI to NotI fragments in the final constructs were verified by sequencing.
Transient expression of Fc-L-SmIIIa. 7.5 ug of the toxin peptide Fc fusion construct pcDNA3.1(+) CMVi-hFc-SmIIIA were transfected into 293-T cells in 10 cm tissue culture plate with FuGENE 6 as transfection reagent. Culture medium was replaced with serum-free medium at 24 hours post-transfection and the conditioned medium was harvested at day 5 post-transfection. Transient expression of Fc-SmIIIA from 293-T cells was analyzed by Western blot probed with anti-hFc antibody (
Cell Culture. Stable cell line expressing human Kv1.3 channel was licensed from Biofocus. Cells were kept at 37° C. in 5% CO2 environment. Culture medium contains DMEM with GlutaMax™ (Invitrogen), 1× non-essential amino acid, 10% fetal bovine serum and 500 μg/mL geneticin. Cells were plated and grown at low confluence on 35 mm culture dishes for at least 24 hours prior to electrophysiology experiments.
Electrophysiology Recording by Patch Clamping. Whole-cell currents were recorded from single cells by using tight seal configuration of the patch-clamp technique. A 35 mm culture dish was transferred to the recording stage after rinsing and replacing the culture medium with recording buffer containing 135 mM NaCl, 5 mM KCl, 1.8 mM CaCl2, 10 mM HEPES, and 5 mM Glucose. pH was adjusted to 7.4 with NaOH and the osmolarity was set at 300 mOsm. Cells were perfused continuously with the recording buffer via one of the glass capillaries arranged in parallel and attached to a motorized rod, which places the glass capillary directly on top of the cell being recorded. Recording pipette solution contained 90 mM K-gluconate, 20 mM KF, 10 mM NaCl, 1 mM MgCl2-6H2O, 10 mM EGTA, 5 mM K2-ATP, and 10 mM HEPES. The pH for the internal solution was adjusted to 7.4 with KOH and the osmolarity was set at 280 mOsm. Experiments were performed at room temperature (20-22° C.) and recorded using Multiclamp™ 700 Å amplifier (Molecular Devices Inc.). Pipette resistances were typically 2-3 MΩ.
Protein toxin potency determination on Kv1.3 current: HEK293 cells stably expressing human Kv1.3 channel were voltage clamped at −80 mV holding potential. Outward Kv1.3 currents were activated by giving 200 msec long depolarizing steps to +30 mV from the holding potential of −80 mV and filtered at 3 kHz. Each depolarizing step was separated from the subsequent one with a 10 s interval. Analogue signals were digitized by Digidata™ 1322A digitizer (Molecular Devices) subsequently stored on computer disk for offline analyses using Clampfit™ 9 (Molecular Devices Inc.). In all studies, stable baseline Kv1.3 current amplitudes were established for 4 minutes before starting the perfusion of the protein toxin at incremental concentrations. A steady state block was always achieved before starting the perfusion of the subsequent concentration of the protein toxin.
Data analysis. Percent of control (POC) is calculated based on the following equation: (Kv1.3 current after protein toxin addition/Kv1.3 current in control)*100. At least 5 concentrations of the protein toxin (e.g. 0.003, 0.01, 0.03, 0.1, 0.3, 100 nM) were used to calculate the IC50 value. IC50 values and curve fits were estimated using the four parameter logistic fit of XLfit software (Microsoft Corp.). IC50 values are presented as mean value±s.e.m. (standard error of the mean).
Drug preparations. Protein toxins (typically 10-100 μM) were dissolved in distilled water and kept frozen at −80° C. Serial dilutions of the stock protein toxins were mixed into the recording buffer containing 0.1% bovine serum albumin (BSA) and subsequently transferred to glass perfusion reservoirs. Electronic pinch valves controlled the flow of the protein toxin from the reservoirs onto the cell being recorded.
Inhibition of T cell cytokine Production following PMA and anti-CD3 antibody stimulation of PBMCs. PBMC's were previously isolated from normal human donor Leukophoresis packs, purified by density gradient centrifugation (Ficoll Hypaque), cryopreserved in CPZ Cryopreservation Medium Complete (INCELL, MCPZF-100 plus 10% DMSO final). PBMC's were thawed (95% viability), washed, and seeded at 2×105 cells per well in culture medium (RPMI medium 1640; GIBCO) supplemented with 10% fetal calf serum, 100 U/ml penicillin, 100 mg/ml streptomycin 2 mM L-glutamine, 100 uM non-essential amino acids, and 20 uM 2-ME) in 96-well flat-bottom tissue culture plates. Cells were pre-incubated with serially diluted (100 nM-0.001 nM final) ShK[1-35], Fc-L10-ShK[1-35] or fc control for 90 min before stimulating for 48 hr with PMA/anti-CD3 (1 ng/ml and 50 ng/ml, respectively) in a final assay volume of 200 ul. Analysis of the assay samples was performed using the Meso Scale Discovery (MSD) SECTOR™ Imager 6000 (Meso Scale Discovery, Gaithersbury, Md.) to measure the IL-2 and IFNg protein levels by utilizing electrochemiluminescence (ECL). The conditioned medium (50 ul) was added to the MSD Multi-spot 96-well plates (each well containing three capture antibodies; IL-2, TNF, IFNγ). The plates were sealed, wrapped in tin foil, and incubated at room temperature on a plate shaker for 2 hr. The wells were washed 1× with 200 ul PBST (BIOTEK, Elx405 Auto Plate Washer). For each well, 20 ul of Ruthenium-labeled detection antibodies (1 μg/ml final in Antibody Dilution Buffer; IL-1, TNF, IFNγ) and 130 ul of 2×MSD Read Buffer added, final volume 150 ul. The plates were sealed, wrapped in tin foil, and incubated at room temperature on a plate shaker for 1 hr. The plates were then read on the SECTOR™ Imager 6000.
Inhibition of T cell cytokine production following anti-CD3 and anti-CD28 antibody stimulation of PBMCs. PBMCs were previously isolated from normal human donor Leukopheresis packs, purified by density gradient centrifugation (Ficoll Hypaque), and cryopreserved using INCELL Freezing Medium. PBMCs were thawed (95% viability), washed, and seeded (in RPMI complete medium containing serum replacement, PSG) at 2×105 cells per well into 96-well flat bottom plates. Cells were pre-incubated with serially diluted (100 nM-0.003 nM final) ShK[1-35], Fc-L10-ShK[1-35], or Fc control for 1 hour before the addition of aCD3 and aCD28 (2.5 ng/mL and 100 ng/mL respectively) in a final assay volume of 200 mL. Supernatants were collected after 48 hours, and analyzed using the Meso Scale Discovery (MSD) SECTOR™ Imager 6000 (Meso Scale Discovery, Gaithersbury, Md.) to measure the IL-2 and IFNg protein levels by utilizing electrochemiluminescence (ECL). 20 mL of supernatant was added to the MSD multi-spot 96-well plates (each well containing IL-2, TNFa, and IFNg capture antibodies). The plates were sealed and incubated at room temperature on a plate shaker for 1 hour. Then 20 mL of Ruthenium-labeled detection antibodies (1 μg/ml final of IL-2, TNFα, and IFNγ in Antibody Dilution Buffer) and 110 mL of 2×MSD Read Buffer were added. The plates were sealed, covered with tin foil, and incubated at room temperature on a plate shaker for 1 hour. The plates were then read on the SECTOR™ Imager 6000.
Inhibition of T cell proliferation following anti-CD3 and anti-CD28 antibody stimulation of PBMCs. PBMC's were previously isolated from normal human donor Leukophoresis packs, purified by density gradient centrifugation (Ficoll Hypaque), cryopreserved in CPZ Cryopreservation Medium Complete (INCELL, MCPZF-100 plus 10% DMSO final). PBMC's were thawed (95% viability), washed, and seeded at 2×105 cells per well in culture medium (RPMI medium 1640; GIBCO) supplemented with 10% fetal calf serum, 100 U/ml penicillin, 100 mg/ml streptomycin, 2 mM L-glutamine, 100 μM non-essential amino acids, and 20 μM 2-ME) in 96-well flat-bottom tissue culture plates. Cells were pre-incubated with either anti-human CD32 (FcyRII) blocking antibody (per manufacturers instructions EASY SEP Human Biotin Selection Kit #18553, StemCell Technologies Vancouver, BC) or Fc-L10-ShK (100 nM-0.001 nM final) for 45 min. Fc-L10-ShK (100 nM-0.001 nM final) was then added to the cells containing anti-human CD32 blocking antibody while medium was added to the cells containing Fc-L10-ShK. Both sets were incubated for an additional 45 min before stimulating for 48 hr with aCD3/aCD28 (0.2 ng/ml and 100 ng/ml, respectively). Final assay volume was 200 ul. [3H]TdR (1 uCi per well) was added and the plates were incubated for an additional 16 hrs. Cells were then harvested onto glass fiber filters and radioactivity was measured in a B-scintillation counter.
Immunohistochemistry analysis of Fc-L10-ShK[1-35] binding to HEK 293 cells overexpressing human Kv1.3. HEK 293 cells overexpressing human Kv1.3 (HEK Kv1.3) were obtained from BioFocus plc (Cambridge, UK) and maintained per manufacturer's recommendation. The parental HEK 293 cell line was used as a control. Cells were plated on Poly-D-Lysine 24 well plates (#35-4414; Becton-Dickinson, Bedford, Mass.) and allowed to grow to approximately 70% confluence. HEK KV1.3 were plated at 0.5×10e5 cells/well in 1 ml/well of medium. HEK 293 cells were plated at a density of 1.5×10e5 cells/well in 1 ml/well of medium. Before staining, cells were fixed with formalin (Sigma HT50-1-1 Formalin solution, diluted 1:1 with PBS/0.5% BSA before use) by removing cell growth medium, adding 0.2 ml/well formalin solution and incubating at room temperature for ten minutes. Cells were stained by incubating with 0.2 ml/well of 5 μg/ml Fc-L10-ShK[1-35] in PBS/BSA for 30′ at room temperature. Fc-L10-ShK[1-35] was aspirated and then the cells were washed one time with PBS/0.5% BSA. Detection antibody (Goat F(ab)2 anti-human IgG-phycoerythrin; Southern Biotech Associates, Birmingham, Ala.) was added to the wells at 5 μg/ml in PBS/0.5% BSA and incubated for 30′ at room temperature. Wash cells once with PBS/0.5% BSA and examine using confocal microscopy (LSM 510 Meta Confocal Microscope; Carl Zeiss AG, Germany).
An ELISA assay demonstrating Fc-L10-ShK[1-35] binding to fixed HEK 293 cells overexpressing Kv1.3.
Expression of Fc-L10-ShK[1-35] was as described in Example 3 herein above. Frozen, E. coli paste (18 g) was combined with 200 ml of room temperature 50 mM tris HCl, 5 mM EDTA, pH 8.0 and was brought to about 0.1 mg/ml hen egg white lysozyme. The suspended paste was passed through a chilled microfluidizer twice at 12,000 PSI. The cell lysate was then centrifuged at 22,000 g for 15 min at 4° C. The pellet was then resuspended in 200 ml 1% deoxycholic acid using a tissue grinder and then centrifuged at 22,000 g for 15 min at 4° C. The pellet was then resuspended in 200 ml water using a tissue grinder and then centrifuged at 22,000 g for 15 min at 4° C. The pellet (3.2 g) was then dissolved in 32 ml 8 M guanidine HCl, 50 mM tris HCl, pH 8.0. The pellet solution was then centrifuged at 27,000 g for 15 min at room temperature, and then 5 ml of the supernatant was transferred to 500 ml of the refolding buffer (3 M urea, 20% glycerol, 50 mM tris, 160 mM arginine HCl, 5 mM EDTA, 1 mM cystamine HCl, 4 mM cysteine, pH 9.5) at 4° C. with vigorous stirring. The stirring rate was then slowed and the incubation was continued for 2 days at 4° C. The refolding solution was then stored at −70° C.
The stored refold was defrosted and then diluted with 2 L of water and the pH was adjusted to 7.3 using 1 M H3PO4. The pH adjusted material was then filtered through a 0.22 μm cellulose acetate filter and loaded on to a 60 ml Amersham SP-FF (2.6 cm I.D.) column at 20 ml/min in S-Buffer A (20 mM NaH2PO4, pH 7.3) at 7° C. The column was then washed with several column volumes of S-Buffer A, followed by elution with a linear gradient from 0% to 60% S-Buffer B (20 mM NaH2PO4, 1 M NaCl, pH 7.3) followed by a step to 100% S-Buffer B at 10 ml/min 7° C. Fractions were then analyzed using a Coomassie brilliant blue stained tris-glycine 4-20% SDS-PAGE, and the fractions containing the desired product were pooled based on these data. The pool was then loaded on to a 1 ml Amersham rProtein A HiTrap column in PBS at 1 ml/min 7° C. Then column was then washed with several column volumes of 20 mM NaH2PO4 pH 6.5, 1 M NaCl and eluted with 100 mM glycine pH 3.0. To the elution peak, 0.0125 volumes (25 ml) of 3 M sodium acetate was added.
A spectral scan was then conducted on 50 μl of the combined pool diluted in 700 μl water using a Hewlett Packard 8453 spectrophotometer (
The IC50 for blockade of human Kv1.3 by purified E. coli-derived Fc-L10-ShK[1-35], also referred to as “Fc-L-ShK[1-35]”, is shown in Table 35 (in Example 50 herein below).
Expression of Fc-L10-ShK[2-35] was as described in Example 4 herein above. Frozen, E. coli paste (16.5 g) was combined with 200 ml of room temperature 50 mM tris HCl, 5 mM EDTA, pH 8.0 and was brought to about 0.1 mg/ml hen egg white lysozyme. The suspended paste was passed through a chilled microfluidizer twice at 12,000 PSI. The cell lysate was then centrifuged at 22,000 g for 15 min at 4° C. The pellet was then resuspended in 200 ml 1% deoxycholic acid using a tissue grinder and then centrifuged at 22,000 g for 15 min at 4° C. The pellet was then resuspended in 200 ml water using a tissue grinder and then centrifuged at 22,000 g for 15 min at 4° C. The pellet (3.9 g) was then dissolved in 39 ml 8 M guanidine HCl, 50 mM tris HCl, pH 8.0. The pellet solution was then centrifuged at 27,000 g for 15 min at room temperature, and then 5 ml of the supernatant was transferred to 500 ml of the refolding buffer (3 M urea, 20% glycerol, 50 mM tris, 160 mM arginine HCl, 5 mM EDTA, 1 mM cystamine HCl, 4 mM cysteine, pH 9.5) at 4° C. with vigorous stirring. The stirring rate was then slowed and the incubation was continued for 2 days at 4° C. The refolding solution was then stored at −70° C.
The stored refold was defrosted and then diluted with 2 L of water and the pH was adjusted to 7.3 using 1 M H3PO4. The pH adjusted material was then filtered through a 0.22 μm cellulose acetate filter and loaded on to a 60 ml Amersham SP-FF (2.6 cm I.D.) column at 20 ml/min in S-Buffer A (20 mM NaH2PO4, pH 7.3) at 7° C. The column was then washed with several column volumes of S-Buffer A, followed by elution with a linear gradient from 0% to 60% S-Buffer B (20 mM NaH2PO4, 1 M NaCl, pH 7.3) followed by a step to 100% S-Buffer B at 10 ml/min 7° C. The fractions containing the desired product were pooled and filtered through a 0.22 μm cellulose acetate filter. The pool was then loaded on to a 1 ml Amersham rProtein A HiTrap column in PBS at 2 ml/min 7° C. Then column was then washed with several column volumes of 20 mM NaH2PO4 pH 6.5, 1 M NaCl and eluted with 100 mM glycine pH 3.0. To the elution peak, 0.0125 volumes (18 ml) of 3 M sodium acetate was added, and the sample was filtered through a 0.22 μm cellulose acetate filter.
A spectral scan was then conducted on 20 μl of the combined pool diluted in 700 μl water using a Hewlett Packard 8453 spectrophotometer (
The IC50 for blockade of human Kv1.3 by purified E. coli-derived Fc-L10-ShK[2-35], also referred to as “Fc-L-ShK[2-35]”, is shown in Table 35 (in Example 50 herein below).
Frozen, E. coli paste (129 g; see Example 10) was combined with 1290 ml of room temperature 50 mM tris HCl, 5 mM EDTA, pH 7.8 and was brought to about 0.1 mg/ml hen egg white lysozyme. The suspended paste was passed through a chilled microfluidizer twice at 12,000 PSI. The cell lysate was then centrifuged at 17,700 g for 15 min at 4° C. The pellet was then resuspended in 1290 ml 1% deoxycholic acid using a tissue grinder and then centrifuged at 17,700 g for 15 min at 4° C. The pellet was then resuspended in 1290 ml water using a tissue grinder and then centrifuged at 17,700 g for 15 min at 4° C. 8 g of the pellet (16.3 g total) was then dissolved in 160 ml 8 M guanidine HCl, 50 mM tris HCl, pH 8.0. 100 ml of the pellet solution was then incubated with 1 ml of 1 M DTT for 60 min at 37° C. The reduced material was transferred to 5000 ml of the refolding buffer (1 M urea, 50 mM tris, 160 mM arginine HCl, 2.5 mM EDTA, 1.2 mM cystamine HCl, 4 mM cysteine, pH 10.5) at 2 ml/min, 4° C. with vigorous stirring. The stirring rate was then slowed and the incubation was continued for 3 days at 4° C.
The pH of the refold was adjusted to 8.0 using acetic acid. The pH adjusted material was then filtered through a 0.22 μm cellulose acetate filter and loaded on to a 50 ml Amersham Q Sepharose-FF (2.6 cm I.D.) column at 10 ml/min in Q-Buffer A (20 mM Tris, pH 8.5) at 8° C. with an inline 50 Amersham Protein A column (2.6 cm I.D.). After loading, the Q Sepharose column was removed from the circuit, and the remaining chromatography was carried out on the protein A column. The column was washed with several column volumes of Q-Buffer A, followed by elution using a step to 100 mM glycine pH 3.0. The fractions containing the desired product were pooled and immediately loaded on to a 50 ml Amersham SP-Sepharose HP column (2.6 cm I.D.) at 20 ml/min in S-Buffer A (20 mM NaH2PO4, pH 7.0) at 8° C. The column was then washed with several column volumes of S-Buffer A followed by a linear gradient from 5% to 60% S-Buffer B (20 mM NaH2PO4, 1 M NaCl, pH 7.0) followed by a step to 100% S-Buffer B. Fractions were then analyzed using a Coomassie brilliant blue stained tris-glycine 4-20% SDS-PAGE. The fractions containing the bulk of the desired product were pooled and then applied to a 75 ml MEP Hypercel column (2.6 cm I.D.) at 5 ml/min in MEP Buffer A (20 mM tris, 200 mM NaCl, pH 8.0) at 8° C. Column was eluted with a linear gradient from 5% to 50% MEP Buffer B (50 mM sodium citrate pH 4.0) followed by a step to 100% MEP Buffer B. Fractions were then analyzed using a Coomassie brilliant blue stained tris-glycine 4-20% SDS-PAGE, and the fractions containing the bulk of the desired product were pooled.
The MEP pool was then concentrated to about 20 ml using a Pall Jumbo-Sep with a 10 kDa membrane followed by buffer exchange with Formulation Buffer (20 mM NaH2PO4, 200 mM NaCl, pH 7.0) using the same membrane. A spectral scan was then conducted on 50 μl of the combined pool diluted in 700 μl Formulation Buffer using a Hewlett Packard 8453 spectrophotometer (
The yield for the E. coli-expressed Fc-L10-OSK1 prep was 81 mg from 40 g of cell paste (129 g×(8 g/16.3 g)×(100 ml/160 ml)=39.6 g which was rounded to 40 g), the purity was greater than 80% judging by SDS-PAGE, it is running as the expected dimer judging by SEC-HPLC, and the mass was within the expected molecular weight range judging by MS.
The IC50 for blockade of human Kv1.3 by purified E. coli-derived Fc-L10-OSK1, also referred to as “Fc-L-OSK1”, is shown in Table 35 (in Example 50 herein below).
Fc-L10-OSK1, Fc-L10-OSK1[K7S], Fc-L10-OSK1[E16K,K20D], and Fc-L10-OSK1 [K7S,E16K,K20D], inhibitors of Kv1.3, were expressed in mammalian cells. A DNA sequence coding for the Fc region of human IgG1 fused in-frame to a linker sequence and a monomer of the Kv1.3 inhibitor peptide OSK1, OSK1[K7S], OSK1[E16K,K20D], or OSK1[K7S,E16K,K20D] was constructed as described below. Methods for expressing and purifying the peptibody from mammalian cells (HEK 293 and Chinese Hamster Ovary cells) are disclosed herein.
For construction of Fc-L10-OSK1, Fc-L10-OSK1[K7S], Fc-L10-OSK1[E16K,K20D], and Fc-L10-OSK1[K7S,E16K,K20D] expression vectors, a PCR strategy was employed to generate the full length genes, OSK1, OSK1[K7S], OSK1[E16K,K20D], and OSK1[K7S,E16K,K20D], each linked to a four glycine and one serine amino acid linker with two stop codons and flanked by BamHI and NotI restriction sites as shown below.
Two oligos for each of OSK1, OSK1[K7S], OSK1[E16K,K20D], and [K7S,E16K,K20D]OSK1 with the sequence as depicted below were used in a PCR reaction with PfuTurbo HotStart DNA polymerase (Stratagene) at 95° C.-30 sec, 55° C.-30 sec, 75° C.-45 sec for 35 cycles; BamHI (ggatcc) and NotI (gcggccgc) restriction sites are underlined.
The resulting PCR products were resolved as the 155 bp bands on a four percent agarose gel. The 155 bp PCR product was purified using PCR Purification Kit (Qiagen), then digested with BamHI and NotI (Roche) restriction enzymes, and agarose gel was purified by Gel Extraction Kit (Qiagen). At the same time, the pcDNA3.1(+) CMVi-hFc-Shk[2-35] vector was digested with BamHI and NotI restriction enzymes and the large fragment was purified by Gel Extraction Kit. The gel purified PCR fragment was ligated to the purified large fragment and transformed into One Shot® Top10F′ (Invitrogen). DNAs from transformed bacterial colonies were isolated and digested with BamHI and NotI restriction enzymes and resolved on a two percent agarose gel. DNAs resulting in an expected pattern were submitted for sequencing. Although, analysis of several sequences of clones yielded a 100% percent match with the above sequences, only one clone from each gene was selected for large scaled plasmid purification. The DNA of Fc-L10-OSK1, Fc-L10-OSK1[K7S], Fc-L10-OSK1[E16K,K20D], and Fc-L10-OSK1[K7S,E16K,K20D] in pCMVi vector was resequenced to confirm the Fc and linker regions and the sequence was 100% identical to the above sequences. The sequences and pictorial representations of Fc-L10-OSK1, Fc-L10-OSK1[K7S], Fc-L10-OSK1[E16K,K20D], and Fc-L10-OSK1[K7S,E16K,K20D] are depicted in
HEK-293 cells used in transient transfection expression of Fc-L110-OSK1, Fc-L10-OSK1[K7S], Fc-L10-OSK1[E16K,K20D], and Fc-L10-OSK1[K7S,E16K,K20D] in pCMVi protein were cultured in growth medium containing DMEM High Glucose (Gibco), 10% fetal bovine serum (FBS from Gibco), 1× non-essential amino acid (NEAA from Gibco) and 1× Penicillin/Streptomycine/Glutamine (Pen/Strep/Glu from Gibco). 5.6 μg each of Fc-L10-OSK1, Fc-L10-OSK1[K7S], Fc-L10-OSK1[E16K,K20D], and Fc-L10-OSK1[K7S,E16K,K20D] in pCMVi plasmid that had been phenol/chloroform extracted was transfected into HEK-293 cells using FuGENE 6 (Roche). The cells were recovered for 24 hours, and then placed in DMEM High Glucose, 1×NEAA and 1× Pen/Strep/Glu medium for 48 hours. Fc-L10-OSK1[K7S], Fc-L10-OSK1[E16K,K20D], and Fc-L10-OSK1[K7S,E16K,K20D] were purified from medium conditioned by these transfected HEK-293 cells using a protocol described in Example 50 herein below.
Fifteen μl of conditioned medium was mixed with an in-house 4× Loading Buffer (without β-mercaptoethanol) and electrophoresed on a Novex 4-20% tris-glycine gel using a Novex Xcell II apparatus at 101V/46 mA for 2 hours in a 1× Gel Running solution (25 mM Tris Base, 192 mM Glycine, 3.5 mM SDS) along with 20 μl of BenchMark Pre-Stained Protein ladder (Invitrogen). The gel was then soaked in Electroblot buffer (25 mM Tris base, 192 mM glycine, 20% methanol,) for 5 minutes. -A nitrocellulose membrane from Invitrogen (Cat. No. LC200, 0.2 μm pores size) was soaked in Electroblot buffer. The pre-soaked gel was blotted to the nitrocellulose membrane using the Mini Trans-Blot Cell module according to the manufacturer instructions (Bio-Rad Laboratories) at 300 mA for 2 hours. The blot was rinsed in Tris buffered saline solution pH7.5 with 0.1% Tween20 (TBST). Then, the blot was first soaked in a 5% milk (Camation) in TBST for 1 hour at room temperature, followed by washing three times in TBST for 10 minutes per wash. Then, incubated with 1:1000 dilution of the HRP-conjugated Goat anti-human IgG, (Fcγ) antibody (Pierece Biotechnology Cat. no. 31413) in TBST with 5% milk buffer for 1 hour with shaking at room temperature. The blot was then washed three times in TBST for 15 minutes per wash at room temperature. The primary antibody was detected using Amersham Pharmacia Biotech's ECL western blotting detection reagents according to manufacturers instructions. Upon ECL detection, the western blot analysis displayed the expected size of 66 kDa under non-reducing gel conditions (
Plasmids containing the Fc-L10-OSK1, Fc-L10-OSK1[K7S], Fc-L10-OSK1[E16K,K20D], and Fc-L10-OSK1[K7S,E16K,K20D] inserts in pCMVi vector were digested with XbaI and NotI (Roche) restriction enzymes and gel purified. The inserts were individually ligated into SpeI and NotI (Roche) digested pDSRα24 (Amgen Proprietary) expression vector. Integrity of the resulting constructs were confirmed by DNA sequencing. Although, analysis of several sequences of clones yielded a 100% percent match with the above sequence, only one clone was selected for large scaled plasmid purification.
AM1 CHOd- (Amgen Proprietary) cells used in the stable expression of Fc-L10-OSK1 protein were cultured in AM1 CHOd- growth medium containing DMEM High Glucose, 10% fetal bovine serum, 1× hypoxantine/thymidine (HT from Gibco), 1×NEAA and 1× Pen/Strep/Glu. 5.6 μg of pDSRα-24-Fc-L10-OSK1 plasmid was transfected into AM1 CHOd- cells using FuGene 6. Twenty-four hours post transfection, the cells were split 1:11 into DHFR selection medium (DMEM High Glucose plus 10% Dialyzed Fetal Bovine Serum (dFBS), 1×NEAA and 1× Pen/Strep/Glu) at 1:50 dilution for colony selection. The cells were selected in DHFR selection medium for thirteen days. The ten 10-cm2 pools of the resulting colonies were expanded to ten T-175 flasks, then were scaled up ten roller bottles and cultured under AM1 CHOd- production medium (DMEM/F12 (1:1), 1×NEAA, 1× Sodium Pyruvate (Na Pyruvate), 1× Pen/Strep/Glu and 1.5% DMSO). The conditioned medium was harvested and replaced at one-week intervals. The resulting six liters of conditioned medium were filtered through a 0.45 μm cellulose acetate filter (Corning, Acton, Mass.), and characterized by SDS-PAGE analysis as shown in
Twelve colonies were selected after 13 days on DHFR selection medium and picked into one 24-well plate. The plate was allowed to grow up for one week, and then was transferred to AM1 CHOd- production medium for 48-72 hours and the conditioned medium was harvested. The expression levels were evaluated by Western blotting similar to the transient Western blot analysis with detection by the same HRP-conjugated Goat anti-human IgG, (Fcγ) antibody to screen 5 μl of conditioned medium. All 12 stable clones exhibited expression at the expected size of 66 kDa. Two clones, A3 and C2 were selected and expanded to T175 flask for freezing with A3 as a backup to the primary clone C2 (
The C2 clone was scaled up into fifty roller bottles (Corning) using selection medium and grown to confluency. Then, the medium was exchanged with a production medium, and let incubate for one week. The conditioned medium was harvested and replaced at the one-week interval. The resulting fifty liters of conditioned medium were filtered through a 0.45 μm cellulose acetate filter (Corning, Acton, Mass.), and characterized by SDS-PAGE analysis (data not shown). Further purification was accomplished as described in Example 42 herein below.
Purification of Fc-L10-OSK1. Approximately 6 L of CHO (AM1 CHOd-) cell-conditioned medium (see, Example 41 above) was loaded on to a 35 ml MAb Select column (GE Healthcare) at 10 ml/min 7° C., and the column was washed with several column volumes of Dulbecco's phosphate buffered saline without divalent cations (PBS) and sample was eluted with a step to 100 mM glycine pH 3.0. The MAb Select elution was directly loaded on to an inline 65 ml SP-HP column (GE Healthcare) in S-Buffer A (20 mM NaH2PO4, pH 7.0) at 10 ml/min 7° C. After disconnecting the MAb select column, the SP-HP column was then washed with several column volumes S-Buffer A, and then developed using a linear gradient from 5% to 60% S-Buffer B (20 mM NaH2PO4, 1 M NaCl, pH 7.0) at 10 ml/min followed by a step to 100% S-Buffer B at 7° C. Fractions were then analyzed using a Coomassie brilliant blue stained tris-glycine 4-20% SDS-PAGE, and the fractions containing the desired product were pooled based on these data. The pooled material was then concentrated to about 20 ml using a Pall Life Sciences Jumbosep 10K Omega centrifugal ultra-filtration device. The concentrated material was then buffer exchanged by diluting with 20 ml of 20 mM NaH2PO4, pH 7.0 and reconcentrated to 20 ml using the Jumbosep 10K Omega filter. The material was then diluted with 20 ml 20 mM NaH2PO4, 200 mM NaCl, pH 7.0 and then reconcentrated to 22 ml. The buffer exchanged material was then filtered though a Pall Life Sciences Acrodisc with a 0.22 μm, 25 mm Mustang E membrane at 1 ml/min room temperature. A spectral scan was then conducted on 50 μl of the filtered material diluted in 700 μl PBS using a Hewlett Packard 8453 spectrophotometer (
The yield for the mammalian Fc-L10-OSK1 prep was 115 mg from 6 L, the purity was >90% judging by SDS-PAGE; Fc-L10-OSK1 ran as the expected dimer judging by SEC-HPLC, and the mass is with the expected range judging by MS.
The activity of purified Fc-L10-OSK1 in blocking human Kv1.3 and human Kv1.1 is described in Example 43 herein below.
Purification of Fc-L10-OSK1(K7S). Fc-L10-OSK1(E16K,K20D), and Fc-L10-OSK1(K7S,E16K,K20D). Approximately 500 mL of medium conditioned by transfected HEK-293 (see, Example 41 above) was combined with a 65% slurry of MAb Select resin (1.5 ml) (GE Healthcare) and 500 μl 20% NaN3. The slurry was then gently agitated for 3 days at 4° C. followed by centrifugation at 1000 g for 5 minutes at 4° C. using no brake. The majority of the supernatant was then aspirated and the remaining slurry in the pellet was transferred to a 14 ml conical tube and combined with 12 ml of Dulbecco's phosphate buffered saline without divalent cations (PBS). The slurry was centrifuged at 2000 g for 1 minute at 4° C. using a low brake and the supernatant was aspirated. The PBS wash cycle was repeated an additional 3 times. The bound protein was then eluted by adding 1 ml of 100 mM glycine pH 3.0 and gently agitating for 5 min at room temperature. The slurry was then centrifuged at 2000 g for 1 minute at 4° C. using a low brake and the supernatant was aspirated as the first elution. The elution cycle was repeated 2 more times, and all 3 supernatants were combined into a single pool. Sodium acetate (37.5 μl of a 3 M solution) was added to the elution pool to raise the pH, which was then dialyzed against 10 mM acetic acid, 5% sorbitol, pH 5.0 for 2 hours at room temperature using a 10 kDa SlideAlyzer (Pierce). The dialysis buffer was changed, and the dialysis continued over night at 4° C. The dialyzed material was then filtered through a 0.22 μm cellulose acetate filter syringe filter. Then concentration of the filtered material was determined to be 1.27 mg/ml using a calculated molecular mass of 30,330 and extinction coefficient of 35,410 M−1 cm−1 (
The activity of purified Fc-L10-OSK1[K7S], Fc-L10-OSK1[E16K, K20D] and Fc-L10-OSK1[K7S, E16K, K20D] in blocking human Kv1.3 and human Kv1.1 is described in Example 43 herein below.
A 38-residue peptide toxin of the Asian scorpion Orthochirus scrobiculosus venom (OSK1) was synthesized (see, Examples 41) to evaluate its impact on the human Kv1.1 and Kv1.3 channels, subtypes of the potassium channel family. The potency and selectivity of synthetic OSK1 in inhibiting the human Kv1.1 and Kv1.3 channels was evaluated by the use of HEK293 cell expression system and electrophysiology (
Fusion of OSK1 peptide toxin to antibody to generate OSK1 peptibody. To improve plasma half-life and prevent OSK1 peptide toxin from penetrating the CNS, the OSK1 peptide toxin was fused to the Fc-fragment of a human antibody IgG1 via a linker chain length of 10 amino acid residues (Fc-L10-OSK1), as described in Example 41 herein. This fusion resulted in a decrease in the potency of Kv1.3 by 5-fold when compared to the synthetic OSK1 peptide. However, it significantly improved the selectivity of OSK1 against Kv1.1 by 210-fold when compared to that of the synthetic peptide alone (4-fold; Table 33 and
Modification of OSK1-peptibody (Fc-L10-OSK1). OSK1 shares 60 to 80% sequence homology to other members of scorpion toxins, which are collectively termed α-KTx3. Sequence alignment of OSK1 and other members of α-KTx3 family revealed 4 distinct structural differences at positions 12, 16, 20, and 36. These structural differences of OSK1 have been postulated to play an important role in its wide range of activities against other potassium channels, which is not observed with other members of α-KTx3 family. Hence, two amino acid residues at position 16 and 20 were restored to the more conserved amino acid residues within the OSK1 sequence in order to evaluate their impact on selectivity against other potassium channels such as Kv1.1, which is predominantly found in the CNS as a heterotetromer with Kv1.2. By substituting for glutamic acid at position 16, and for lysine at position 20, the conserved lysine and aspartic acid residues, respectively (i.e., Fc-L10-OSK1[E16K, K20D]), we did not observe a significant change in potency when compared to that of Fc-L10-OSK1 (1.3-fold difference;
As demonstrated by the results in Table 33, we dramatically improved selectivity against Kv1.1 by fusing the OSK1 peptide toxin to the Fc-fragment of the human antibody IgG1, but reduced target potency against Kv1.3. The selectivity against Kv1.1 was further improved when 2 residues at two key positions were restored to the conserved residues found in other members of the α-KTx3 family.
Table 33 shows a summary of IC50 values for OSK1 and OSK1 analogs against hKv1.3 and hKv1.1 channels. All analogues are ranked based on their potency against hKv1.3. Also shown in the table is the selectivity ratio of hKv1.1/hKv1.3 for all OSK1 analogs.
The intravenous (IV) pharmacokinetic profile was determined of a about 24-kDa 20K PEG-ShK[1-35] molecule and the about 4-kDa small native ShK peptide was determined in Spraque Dawley rats. The IV dose for the native ShK peptide and our novel 20K PEG-ShK[1-35] molecule was 1 mg/kg. This dose represented equal molar amounts of these two molecules. The average weight of the rats was about 0.3 kg and two rats were used for each dose & molecule. At various times following IV injection, blood was drawn and about 0.1 ml of serum was collected. Serum samples were stored frozen at −80° C. until analysis.
Assay Plate preparation for electrophysiology. Rat serum samples containing the 20K PEG-ShK[1-35] molecule or the native ShK peptide from pharmacokinetic studies were received frozen. Before experiments, each sample was thawed at room temperature and an aliquot (70 to 80 μl) was transferred to a well in a 96-well polypropylene plate. In order to prepare the Assay Plate, several dilutions were made from the pharmacokinetic serum samples to give rise to Test Solutions. Dilutions of serum samples from the pharmacokinetic study were into 10% Phosphate Buffered Saline (PBS, with Ca2, and Mg2+). For determination of the amount of our novel 20K PEG-ShK[1-35] molecule in serum samples from the pharmacokinetic study, the final serum concentrations in the Test Solutions were 90%, 30%, 10%, 3.3% and 1.1%. Purified 20K PEG-Shk[1-35] Standard inhibition curves were also prepared in the Assay Plate. To do this, 8-point serial dilutions of the purified 20K PEG-ShK[1-35] molecule (Standard) were prepared in either 90%, 30%, 10%, 3.3% or 1.1% rat serum and the final concentration of standard was 50, 16.7, 5.5, 1.85, 0.62, 0.21, 0.068 and 0.023 nM.
Cell preparation for electrophysiology. CHO cells stably expressing the voltage-activated K+ channel, KV1.3 were plated in T-175 tissue culture flasks (at a density of 5×106) 2 days before experimentation and allowed to grow to around 95% confluence. Immediately prior to the experiment, the cells were washed with PBS and then detached with a 2 ml mixture (1:1 volume ratio) of trypsin (0.25%) and versene (1:5000) at 37° C. (for 3 minutes). Subsequently, the cells were re-suspended in the flask in 10 ml of tissue culture medium (HAM's F-12 with Glutamax, Invitrogen, Cat#31765) with 10% FBS, 1×NEAA and 750 μg/ml of G418) and centrifuged at about 1000 rpm for 1½ minutes. The resultant cell pellet was re-suspended in PBS at 3-5×106 cells/ml.
IonWorks electrophysiology and data analysis. The ability of Test solutions or Standards in serum to inhibit K+ currents in the CHO-Kv1.3 cells was investigated using the automated electrophysiology system, IonWorks Quattro. Re-suspended cells, the Assay Plate, a Population Patch Clamp (PPC) PatchPlate as well as appropriate intracellular (90 mMK-Gluconate, 20 mMKF, 2 mM NaCl, 1 mM MgCl2, 10 mM EGTA, 10 mM HEPES, pH 7.35) and extracellular (PBS, with Ca2+ and Mg2+) buffers were positioned on IonWorks Quattro. Electrophysiology recordings were made from the CHO-Kv1.3 cells using an amphotericin-based perforated patch-clamp method. Using the voltage-clamp circuitry of the IonWorks Quattro, cells were held at a membrane potential of −80 mV and voltage-activated K+ currents were evoked by stepping the membrane potential to +30 mV for 400 ms. K+ currents were evoked under control conditions i.e., in the absence of inhibitor at the beginning of the experiment and after 10-minute incubation in the presence of the Test Solution or Standard. The mean K+ current amplitude was measured between 430 and 440 ms and the data were exported to a Microsoft Excel spreadsheet. The amplitude of the K+ current in the presence of each concentration of the Test Solution or Standard was expressed as a percentage of the K+ current in control conditions in the same well.
Standard inhibition curves were generated for each standard in various levels of rat serum and expressed as current percent of control (POC) versus log of nM concentration. Percent of control (POC) is inversely related to inhibition, where 100 POC is no inhibition and 0 POC is 100% inhibition. Linear regression over a selected region of the curve was used to derive an equation to enable calculation of drug concentrations within Test solutions. Only current values within the linear portion of the Standard curve were used to calculate the concentration of drug in Test solutions. The corresponding Standard curve in a given level of serum, was always compared to the same level of serum of Test solution when calculating drug level. The Standard curves for ShK and 20K PEG-ShK[1-35] are shown in
The pharmacokinetic profile of our novel 20K PEG ShK[1-35] molecule after IV injection is shown in
The 20KPEG-ShK inhibitor of Kv1.3 shows improved efficacy in suppressing severe autoimmune encephalomyelitis in rats. Using an adoptive transfer experimental autoimmune encephalomyelitis (AT-EAE) model of multiple sclerosis described earlier [C. Beeton et al. (2001) J. Immunol. 166, 936], we examined the activity in vivo of our novel 20KPEG-ShK molecule and compared its efficacy to that of the ShK toxin peptide alone. The study design is illustrated in
The 35-amino acid toxin peptide ShK (Stichodactyla helianthus neurotoxin) was purchased from Bachem Bioscience Inc and confirmed by electrophysiology to potently block Kv1.3 (see Example 36 herein). The synthesis, PEGylation and purification of the 20KPEG ShK molecule was as described herein above. The encephalomyelogenic CD4+ rat T cell line, PAS, specific for myelin-basic protein (MBP) originated from Dr. Evelyne Beraud. The maintenance of these cells in vitro and their use in the AT-EAE model has been described earlier [C. Beeton et al. (2001) PNAS 98, 13942]. PAS T cells were maintained in vitro by alternating rounds of antigen stimulation or activation with MBP and irradiated thymocytes (2 days), and propagation with T cell growth factors (5 days). Activation of PAS T cells (3×105/ml) involved incubating the cells for 2 days with 10 μg/ml MBP and 15×106/ml syngeneic irradiated (3500 rad) thymocytes. On day 2 after in vitro activation, 10-15×106 viable PAS T cells were injected into 6-12 week old female Lewis rats (Charles River Laboratories) by tail IV. Daily subcutaneous injections of vehicle (2% Lewis rat serum in PBS), 20KPEG-ShK or ShK were given from days −1 to 3 (
Treatment of rats with the Kv1.3 blocker PEG-ShK prior to the onset of EAE caused a lag in the onset of disease, inhibited the progression of disease, and prevented death in a dose-dependent manner (
Ex vivo assay to examine impact of Kv1.3 inhibitors on secretion of IL-2 and IFN-g. Human whole blood was obtained from healthy, non-medicated donors in a heparin vacutainer. DMEM complete media was Iscoves DMEM (with L-glutamine and 25 mM Hepes buffer) containing 0.1% human albumin (Bayer #68471), 55 μM 2-mercaptoethanol (Gibco), and 1× Pen-Strep-Gln (PSG, Gibco, Cat#10378-016). Thapsigargin was obtained from Alomone Labs (Israel). A 10 mM stock solution of thapsigargin in 100% DMSO was diluted with DMEM complete media to a 40 μM, 4× solution to provide the 4× thapsigargin stimulus for calcium mobilization. The Kv1.3 inhibitor peptide ShK (Stichodacytla helianthus toxin, Cat# H2358) and the BKCa1 inhibitor peptide IbTx (Iberiotoxin, Cat# H9940) were purchased from Bachem Biosciences, whereas the Kv1.1 inhibitor peptide DTX-k (Dendrotoxin-K) was from Alomone Labs (Israel). The CHO-derived Fc-L10-ShK[2-35] peptibody inhibitor of Kv1.3 was obtained as described herein at Example 4 and Example 39. The calcineurin inhibitor cyclosporin A was obtained from the Amgen sample bank, but is also available commercially from a variety of vendors. Ten 3-fold serial dilutions of inhibitors were prepared in DMEM complete media at 4× final concentration and 50 μl of each were added to wells of a 96-well Falcon 3075 flat-bottom microtiter plate. Whereas columns 1-5 and 7-11 of the microtiter plate contained inhibitors (each row with a separate inhibitor dilution series), 50 μl of DMEM complete media alone was added to the 8 wells in column 6 and 100 μl of DMEM complete media alone was added to the 8 wells in column 12. To initiate the experiment, 100 μl of whole blood was added to each well of the microtiter plate. The plate was then incubated at 37° C., 5% CO2 for one hour. After one hour, the plate was removed and 50 μl of the 4× thapsigargin stimulus (40 μM) was added to all wells of the plate, except the 8 wells in column 12. The plates were placed back at 37° C., 5% CO2 for 48 hours. To determine the amount of IL-2 and IFN-g secreted in whole blood, 100 μl of the supernatant (conditioned media) from each well of the 96-well plate was transferred to a storage plate. For MSD electrochemilluminesence analysis of cytokine production, 20 μl of the supernatants (conditioned media) were added to MSD Multi-Spot Custom Coated plates (www.meso-scale.com). The working electrodes on these plates were coated with four Capture Antibodies (hIL-5, hIL-2, hlFNg and hIL-4) in advance. After addition of 20 μl of conditioned media to the MSD plate, 150 μl of a cocktail of Detection Antibodies and P4 Buffer were added to each well. The 150 μl cocktail contained 20 ul of four Detection Antibodies (hIL-5, hIL-2, hIFNg and hIL-4) at 1 μg/ml each and 130 ul of 2×P4 Buffer. The plates were covered and placed on a shaking platform overnight (in the dark). The next morning the plates were read on the MSD Sector Imager. Since the 8 wells in column 6 of each plate received only the thapsigargin stimulus and no inhibitor, the average MSD response here was used to calculate the “High” value for a plate. The calculate “Low” value for the plate was derived from the average MSD response from the 8 wells in column 12 which contained no thapsigargin stimulus and no inhibitor. Percent of control (POC) is a measure of the response relative to the unstimulated versus stimulated controls, where 100 POC is equivalent to the average response of thapsigargin stimulus alone or the “High” value. Therefore, 100 POC represents 0% inhibition of the response. In contrast, 0 POC represents 100% inhibition of the response and would be equivalent to the response where no stimulus is given or the “Low” value. To calculate percent of control (POC), the following formula is used: [(MSD response of well)−(“Low”)]/[(“High”)−(“Low”)]×100. The potency of the molecules in whole blood was calculated after curve fitting from the inhibition curve (IC) and IC50 was derived using standard curve fitting software. Although we describe here measurement of cytokine production using a high throughput MSD electrochemillumenescence assay, one of skill in the art can readily envision lower throughput ELISA assays are equally applicable for measuring cytokine production.
Ex vivo assay demonstrating Kv1.3 inhibitors block cell surface activation of CD40L & IL-2R. Human whole blood was obtained from healthy, non-medicated donors in a heparin vacutainer. DMEM complete media was Iscoves DMEM (with L-glutamine and 25 mM Hepes buffer) containing 0.1% human albumin (Bayer #68471), 55 μM 2-mercaptoethanol (Gibco), and 1× Pen-Strep-Gln (PSG, Gibco, Cat#10378-016). Thapsigargin was obtained from Alomone Labs (Israel). A 10 mM stock solution of thapsigargin in 100% DMSO was diluted with DMEM complete media to a 40 μM, 4× solution to provide the 4× thapsigargin stimulus for calcium mobilization. The Kv1.3 inhibitor peptide ShK (Stichodacytla helianthus toxin, Cat# H2358) and the BKCa1 inhibitor peptide IbTx (Iberiotoxin, Cat# H9940) were purchased from Bachem Biosciences, whereas the Kv1.1 inhibitor peptide DTX-k (Dendrotoxin-K) was from Alomone Labs (Israel). The CHO-derived Fc-L110-ShK[2-35] peptibody inhibitor of Kv1.3 was obtained as described in Example 4 and Example 39. The calcineurin inhibitor cyclosporin A was obtained from the Amgen sample bank, but is also available commercially from a variety of vendors. The ion channel inhibitors ShK, IbTx or DTK-k were diluted into DMEM complete media to 4× of the final concentration desired (final=50 or 100 nM). The calcineurin inhibitor cyclosporin A was also diluted into DMEM complete media to 4× final concentration (final=10 μM). To appropriate wells of a 96-well Falcon 3075 flat-bottom microtiter plate, 50 μl of either DMEM complete media or the 4× inhibitor solutions were added. Then, 100 μl of human whole blood was added and the plate was incubated for 1 hour at 37° C., 5% CO2. After one hour, the plate was removed and 50 μl of the 4× thapsigargin stimulus (40 μM) was added to all wells of the plate containing inhibitor. To some wells containing no inhibitor but just DMEM complete media, thapsigargin was also added whereas others wells with just DMEM complete media had an additional 50 μl of DMEM complete media added. The wells with no inhibitor and no thapsigargin stimulus represented the untreated “Low” control. The wells with no inhibitor but which received thapsigargin stimulus represented the control for maximum stimulation or “High” control. Plates were placed back at 37° C., 5% CO2 for 24 hours. After 24 hours, plates were removed and wells were process for FACS analysis. Cells were removed from the wells and washed in staining buffer (phosphate buffered saline containing 2% heat-inactivated fetal calf serum). Red blood cells were lysed using BD FACS Lysing Solution containing 1.5% formaldehyde (BD Biosciences) as directed by the manufacturer. Cells were distributed at a concentration of 1 million cells per 100 microliters of staining buffer per tube. Cells were first stained with 1 microliter of biotin-labeled anti-human CD4, washed, then stained simultaneously 1 microliter each of streptavidin-APC, FITC-labeled anti-human CD45RA, and phycoerythrin (PE)-labeled anti-human CD25 (IL-2Ra) or PE-labeled anti-human CD40L. Cells were washed with staining buffer between antibody addition steps. All antibodies were obtained from BD Biosciences (San Diego, Calif.). Twenty to fifty thousand live events were collected for each sample on a Becton Dickinson FACSCaliber (Mountain View, Calif.) flow cytometer and analyzed using FlowJo software (Tree Star Inc., San Carlos, Calif.). Dead cells, monocytes, and granulocytes were excluded from the analysis on the basis of forward and side scatter properties.
By way of example, PEGylated peptibodies of the present invention were made by the following method. CHO-expressed FcL10-OsK1 (19.2 mg; MW 30,371 Da, 0.63 micromole) in 19.2 ml A5S, 20 mM NaBH3CN, pH 5, was treated with 38 mg PEG aldehyde (MW 20 kDa; 3×, Lot 104086). The sealed reaction mixture was stirred in a cold room overnight. The extent of the protein modification during the course of the reaction was monitored by SEC HPLC using a Superose 6 HR 10/30 column (Amersham Pharmacia Biotech) eluted with a 0.05 M phosphate buffer, 0.5 M NaCl, pH 7.0 at 0.4 ml/min. The reaction mixture was dialyzed with A5S, pH 5 overnight. The dialyzed material was then loaded onto an SP HP FPLC column (16/10) in A5S pH 5 and eluted with a 1 M NaCl gradient. The collected fractions were analyzed by SEC HPLC, pooled into 3 pools, exchanged into DPBS, concentrated and submitted for functional testing (Table 34).
In another example, FcL10-ShK1 (16.5 mg; MW 30,065 Da, 0.55 micro mole) in 16.5 ml A5S, 20 mM NaBH3CN, pH 5 was treated with 44 mg PEG aldehyde (MW 20 kDa; 4×, Lot 104086). The sealed reaction mixture was stirred in a cold room overnight. The extent of the protein modification during the course of the reaction was monitored by SEC HPLC using a Superose 6 HR 10/30 column (Amersham Pharmacia Biotech) eluted with a 0.05 M phosphate buffer, 0.5 M NaCl, pH 7.0 at 0.4 ml/min. The reaction mixture was dialyzed with A5S, pH 5 overnight. The dialyzed material was loaded onto an SP HP FPLC column (16/10) in A5S pH 5 and was eluted with a 1 M NaCl gradient. The collected fractions were analyzed by SEC HPLC, pooled into 3 pools, exchanged into DPBS, concentrated and submitted for functional testing (Table 34).
The data in Table 34 demonstrate potency of the PEGylated peptibody molecules as Kv1.3 inhibitors.
Table 34 shows determinations of IC50 made by whole cell patch clamp electrophysiology with HEK 293 as described in Example 36 herein above. The sustained IC50 was derived from the current 400 msecs after voltage ramp from −80 mV to +30 mV. Pool #2 samples comprised di-PEGylated peptibodies and Pool #3 samples comprised mono-PEGylated peptibodies.
Shk and Osk-1 PEGylation, purification and analysis. Synthetic Shk or OSK1-1 toxin peptides were selectively PEGylated by reductive alkylation at their N-termini. Conjugation was achieved, with either Shk or OSK-1 toxin peptides, at 2 mg/ml in 50 mM NaH2PO4, pH 4.5 reaction buffer containing 20 mM sodium cyanoborohydride and a 2 molar excess of 20 kDa monomethoxy-PEG-aldehyde (Nektar Therapeutics, Huntsville, Ala.). Conjugation reactions were stirred overnight at room temperature, and their progress was monitored by RP-HPLC. Completed reactions were quenched by 4-fold dilution with 20 mM NaOAc, pH 4, adjusted to pH 3.5 and chilled to 4° C. The PEG-peptides were then purified chromatographically at 4° C.; using SP Sepharose HP columns (GE Healthcare, Piscataway, N.J.) eluted with linear 0-1M NaCl gradients in 20 mM NaOAc, pH 4.0. (
Electrophysiology performed by patch clamp on whole cells (see, Example 36) yielded a peak IC50 of 1.285 nM for PEG-OSK1 and 0.169 nM for PEG-ShK[1-35] (
PEG conjugates of OSK1 peptide analogs were also generated and tested for activity in blocking T cell inflammation in the human whole blood assay (Example 46). As shown in Table 43, OSK1[Ala12], OSK1[Ala29], OSK1[Nal34] and OSK1[Ala29, 1Nal34] analogs containing an N-terminal 20K PEG conjugate, all provided potent blockade of the whole blood cytokine response in this assay. The 20K PEG-ShK was also highly active (Table 43).
As exemplified in
The peptide insertion for these examples was between Fc residues Leu139 and Thr140 and included 2-4 Gly residues as linkers flanking either side of the inserted peptide. However, alternate insertion sites for the human IgG1 Fc sequence, or different linkers, are also useful in the practice of the present invention, as is known in the art, e.g., as described in Example 13 of Gegg et al., Modified Fc molecules, WO 2006/036834 A2 [PCT/US2005/034273]).
Purified FcLoop OSK1 and FcLoop ShK1 molecules were tested in the whole blood assay of inflammation (see, Example 46). FcLoop-L2-OsK1-L2, FcLoop-L4-OsK1-L4 and FcLoop-L2-ShK-L2 toxin conjugates all provided potent blockade of the whole blood cytokine response in this assay, with IC50 values in the pM range (Table 43).
Frozen, E. coli paste (117 g), obtained as described in Example 16 herein above, was combined with 1200 ml of room temperature 50 mM tris HCl, 5 mM EDTA, pH 7.5 and was brought to about 0.1 mg/ml hen egg white lysozyme. The suspended paste was passed through a chilled microfluidizer twice at 12,000 PSI. The cell lysate was then centrifuged at 17,700 g for 30 min at 4° C. The pellet was then resuspended in 1200 ml 1% deoxycholic acid using a tissue grinder and then centrifuged at 17,700 g for 30 min at 4° C. The pellet was then resuspended in 1200 ml water using a tissue grinder and then centrifuged at 17,700 g for 30 min at 4° C. 6.4 g of the pellet (total 14.2 g) was then dissolved in 128 ml 8 M guanidine HCl, 50 mM tris HCl, pH 8.0. 120 ml of the pellet solution was then incubated with 0.67 ml of 1 M DTT for 60 min at 37° C. The reduced material was transferred to 5500 ml of the refolding buffer (3 M urea, 50 mM tris, 160 mM arginine HCl, 2.5 mM EDTA, 2.5 mM cystamine HCl, 4 mM cysteine, pH 9.5) at 2 ml/min, 4° C. with vigorous stirring. The stirring rate was then slowed and the incubation was continued for 3 days at 4° C.
The refold was diluted with 5.5 L of water, and the pH was adjusted to 8.0 using acetic acid, then the solution was filtered through a 0.22 μm cellulose acetate filter and loaded on to a 35 ml Amersham Q Sepharose-FF (2.6 cm I.D.) column at 10 ml/min in Q-Buffer A (20 mM Tris, pH 8.5) at 8° C. with an inline 35 ml Amersham Mab Select column (2.6 cm I.D.). After loading, the Q Sepharose column was removed from the circuit, and the remaining chromatography was carried out on the Mab Select column. The column was washed with several column volumes of Q-Buffer A, followed by elution using a step to 100 mM glycine pH 3.0. The fractions containing the desired product immediately loaded on to a 5.0 ml Amersham SP-Sepharose HP column at 5.0 ml/min in S-Buffer A (10 mM NaH2PO4, pH 7.0) at 8° C. The column was then washed with several column volumes of S-Buffer A followed by a linear gradient from 5% to 60% S-Buffer B (10 mM NaH2PO4, 1 M NaCl, pH 7.0) followed by a step to 100% S-Buffer B. Fractions were then analyzed using a Coomassie brilliant blue stained tris-glycine 4-20% SDS-PAGE. The fractions containing the bulk of the desired product were pooled and then applied to a 50 ml MEP Hypercel column (2.6 cm I.D.) at 10 ml/min in MEP Buffer A (20 mM tris, 200 mM NaCl, pH 8.0) at 8° C. Column was eluted with a linear gradient from 5% to 50% MEP Buffer B (50 mM sodium citrate pH 4.0) followed by a step to 100% MEP Buffer B. Fractions were then analyzed using a Coomassie brilliant blue stained tris-glycine 4-20% SDS-PAGE, and the fractions containing the bulk of the desired product were pooled.
The MEP-pool was then concentrated to about 10 ml using a Pall Jumbo-Sep with a 10 kDa membrane. A spectral scan was then conducted on 50 μl of the combined pool diluted in 700 μl PBS using a Hewlett Packard 8453 spectrophotometer (
In Table 35, IC50 data for the purified E. coli-derived ShK[2-35]-L-Fc are compared to some other embodiments of the inventive composition of matter.
Table 35. E. coli-derived recombinant Fc-L-ShK[1-35], Fc-L-ShK[2-35], Fc-L-OSK1, Shk[1-35]-L-Fc and ShK[2-35]-L-Fc peptibodies containing Fc at either the N-terminus or C-terminus show potent blockade of human Kv1.3. The activity of the CHO-derived Fc-L10-ShK[1-35] R1Q mutant is also shown. Whole cell patch clamp electrophysiology (WCVC), by methods described in Example 36, was performed using HEK293/Kv1.3 cells and the IC50 shown is the average from dose-response curves from 3 or more cells. IonWorks™ (IWQ) planar patch clamp electrophysiology by methods described in Example 44 was on CHO/Kv1.3 cells and the average IC50 is shown. The inventive molecules were obtained by methods as described in the indicated Example: E. coli-derived Fc-L-ShK[1-35] (Example 3 and Example 38), E. coli-derived Fc-L-ShK[2-35] (Example 4 and Example 39), E. coli Fc-L-OSK1 (Example 10 and Example 40), ShK[1-35]-L-Fc (Example 15 and Example 51), and ShK[2-35]-L-Fc (Example 16 and this Example 50). CHO-derived Fc-L10-ShK[1-35] R1Q molecule was generated using methods similar to those described for CHO-derived Fc-L10-ShK[1-35].
E. coli-derived Fc-L-ShK[1-35]
E. coli-derived Fc-L-ShK[2-35]
E. coli-derived Fc-L-OSK1
E. coli-derived Shk[1-35]-L-Fc
E. coli-derived ShK[2-35]-L-Fc
Frozen, E. coli paste (65 g), obtained as described in Example 15 herein above was combined with 660 ml of room temperature 50 mM tris HCl, 5 mM EDTA, pH 7.5 and was brought to about 0.1 mg/ml hen egg white lysozyme. The suspended paste was passed through a chilled microfluidizer twice at 12,000 PSI. The cell lysate was then centrifuged at 17,700 g for 30 min at 4° C. The pellet was then resuspended in 660 ml 1% deoxycholic acid using a tissue grinder and then centrifuged at 17,700 g for 30 min at 4° C. The pellet was then resuspended in 660 ml water using a tissue grinder and then centrifuged at 17,700 g for 30 min at 4° C. 13 g of the pellet was then dissolved in 130 ml 8 M guanidine HCl, 50 mM tris HCl, pH 8.0. 10 ml of the pellet solution was then incubated with 0.1 ml of 1 M DTT for 60 min at 37° C. The reduced material was transferred to 1000 ml of the refolding buffer (2 M urea, 50 mM tris, 160 mM arginine HCl, 2.5 mM EDTA, 1.2 mM cystamine HCl, 4 mM cysteine, pH 8.5) at 2 ml/min, 4° C. with vigorous stirring. The stirring rate was then slowed and the incubation was continued for 3 days at 4° C.
The refold was diluted with 1 L of water, and filtered through a 0.22 μm cellulose acetate filter then loaded on to a 35 ml Amersham Q Sepharose-FF (2.6 cm I.D.) column at 10 ml/min in Q-Buffer A (20 mM Tris, pH 8.5) at 8° C. with an inline 35 ml Amersham Mab Select column (2.6 cm I.D.). After loading, the Q Sepharose column was removed from the circuit, and the remaining chromatography was carried out on the Mab Select column. The column was washed with several column volumes of Q-Buffer A, followed by elution using a step to 100 mM glycine pH 3.0. The fractions containing the desired product immediately loaded on to a 5.0 ml Amersham SP-Sepharose HP column at 5.0 ml/min in S-Buffer A (20 mM NaH2PO4, pH 7.0) at 8° C. The column was then washed with several column volumes of S-Buffer A followed by a linear gradient from 5% to 60% S-Buffer B (20 mM NaH2PO4, 1 M NaCl, pH 7.0) followed by a step to 100% S-Buffer B. Fractions were then analyzed using a Coomassie brilliant blue stained tris-glycine 4-20% SDS-PAGE. The fractions containing the bulk of the desired product were pooled.
The S-pool was then concentrated to about 10 ml using a Pall Jumbo-Sep with a 10 kDa membrane. A spectral scan was then conducted on 20 μl of the combined pool diluted in 700 μl PBS using a Hewlett Packard 8453 spectrophotometer (
An aliquot of the sample was spotted with the MALDI matrix sinapinic acid on sample plate. A Voyager DE-RP time-of-flight mass spectrometer equipped with a nitrogen laser (337 nm, 3 ns pulse) was used to collect spectra. The positive ion/linear mode was used, with an accelerating voltage of 25 kV. Each spectrum was produced by accumulating data from ˜200 laser shots (
The IC50 for blockade of human Kv1.3 by purified E. coli-derived Met-ShK(1-35)-Fc, also referred to as “ShK[1-35]-L-Fc”, is shown in Table 35 herein above.
The methods to clone and express the peptibody in bacteria were as described in Example 3. The vector used was pAMG21amgR-pep-Fc and the oligos listed below were used to generate a duplex (see below) for cloning and expression in bacteria of OsK1-L-Fc. Oligos used to form duplex are shown below:
The oligos shown above were used to form the duplex shown below:
Bacterial expression of the peptibody was as described in Example 3 and paste was stored frozen.
The methods to clone and express the peptibody in bacteria were as described in Example 3. The vector used was pAMG21amgR-pep-Fc and the oligos listed below were used to generate a duplex (see below) for cloning and expression in bacteria of Gly-ShK(1-35)-L-Fc. Oligos used to form duplex are shown below:
The oligos shown above were used to form the duplex shown below:
Bacterial expression of the peptibody was as described in Example 3 and paste was stored frozen.
The methods to clone and express the fusion of a CH2 domain of an Fc with OSK1 in bacteria were generally as described in Example 3. The vector used was pAMG21.G2.H6.G3.CH2.(G4S)2.OSK. Briefly, the pAMG21 vector was modified to remove the multi-cloning site's BamHI. This allowed the BamHI in front of the OSK as a site to swap out different sequences for fusion with the OSK. The sequence upstream of the OSK1 coding sequence was ligated between the NdeI and BamHI sites.
The sequence of the entire vector, including the insert was the following:
The insert DNA sequence was the following:
The amino acid sequence of the CH2-OSK1 fusion protein product was the following:
SEQ ID NO:4917 includes the OSK1 sequence
Purification and refolding of CH2-OSK1 expressed in bacteria. Frozen, E. coli paste (13.8 g) was combined with 180 ml of room temperature 50 mM tris HCl, 5 mM EDTA, pH 8.0 and was brought to about 0.1 mg/ml hen egg white lysozyme. The suspended paste was passed through a chilled microfluidizer twice at 12,000 PSI. The cell lysate was then centrifuged at 17,700 g for 50 min at 4° C. The pellet was then resuspended in 90 ml 1% deoxycholate using a tissue grinder and then centrifuged at 15,300 g for 40 min at 4° C. The pellet was then resuspended in 90 ml water using a tissue grinder and then centrifuged at 15,300 g for 40 min at 4° C. The pellet (3.2 g) was then dissolved in 64 ml 8 M guanidine HCl, 50 mM tris HCl, pH 8.0. The suspension was then incubated at room temperature (about 23° C.) for 30 min with gentle agitation followed by centrifugation at 15,300 g for 30 min at 4° C. The supernatant (22 ml) was then reduced by adding 220 μl 1 M dithiothreitol and incubating at 37° C. for 30 minutes. The reduced suspension (20 ml) was transferred to 2000 ml of the refolding buffer (1 M urea, 50 mM ethanolamine, 160 mM arginine HCl, 0.02% NaN3, 1.2 mM cystamine HCl, 4 mM cysteine, pH 9.8) at 4° C. with vigorous stirring. The stirring rate was then slowed and the incubation was continued for approximately 2.5 days at 4° C.
Ten milliliters of 500 mM imidazole was added to the refolding solution and the pH was adjusted to pH to 8.0 with 5 M acetic acid. The refold was then filtered through a 0.45 μm cellulose acetate filter with two pre-filters. This material was then loaded on to a 50 ml Qiagen Ni-NTA Superflow column (2.6 cm ID) in Ni-Buffer A (50 mM NaH2PO4, 300 mM NaCl, pH 7.5) at 15 ml/min 13° C. The column was then washed with 10 column volumes of Ni-Buffer A followed by 8% Ni-Buffer B (250 mM imidazole, 50 mM NaH2PO4, 300 mM NaCl, pH 7.5) at 25 ml/min. The column was then eluted with 60% Ni-Buffer B followed by 100% Ni-Buffer B at 10 ml/min. The peak fractions were collected and dialyzed against S-Buffer A (10 mM NaH2PO4, pH 7.1)
The dialyzed sample was then loaded on to a 5 ml Amersham SP-HP HiTrap column at 5 ml/min in S-Buffer A at 13° C. The column was then washed with several column volumes of S-Buffer A, followed by elution with a linear gradient from 0% to 60% S-Buffer B (10 mM NaH2PO4, 1 M NaCl, pH 7.1) followed by a step to 100% S-Buffer B at 1.5 ml/min 13° C. Fractions were then analyzed using a Coomassie brilliant blue stained tris-glycine 4-20% SDS-PAGE, and the fractions containing the desired product were pooled based on these data. The pool was then concentrated to about 1.6 ml using a Pall Macrosep with a 10 kDa membrane at 4° C. The concentrated sample was then filtered through a 0.22 μm cellulose acetate centrifugal filter.
A spectral scan was then conducted on 10 μl of the combined pool diluted in 150 μl water using a Hewlett Packard 8453 spectrophotometer (
PEGylation of CH2-OSK1. The CH2-OSK1 fusion protein was diluted to 2 mg/ml in 50 mM sodium acetate, 10 mM sodium cyanoborohydride, pH 4.8 with a 4-fold molar excess of 20 kD methoxy-PEG-aldehyde (Nektar Therapeutics, Huntsville, Ala.). The reaction was allowed to proceed overnight (˜18 hrs) at 4° C. Upon completion, reaction was quenched with 4 volumes of 10 mM sodium acetate, 50 mM NaCl, pH 5, then loaded at 0.7 mg protein/ml resin to an SP Sepharose HP column (GE Healthcare, Piscataway, N.J.) equilibrated in 10 mM sodium acetate, 50 mM NaCl, pH 5. The mono-PEGylated CH2-Osk fusion was eluted with a linear 50 mM-1 M NaCl gradient (
As shown in Table 43, the purified CH2-OSK1 (“L2-6H-L3-CH2-L10-OsK1(1-38)”) and PEGylated CH2-OSK1 (“20 k PEG-L2-6H-L3-CH2-L10-OSK1(1-38)”) molecules were active in blocking inflammation in the human whole blood assay (See, Example 46).
The activity of OSK1 peptide analogs in blocking human Kv1.3 versus human Kv1.1 current is shown in
The novel OSK1 peptide analogs described in this application which inhibit Kv1.3 are useful in the treatment of autoimmune disease and inflammation. Kv1.3 is expressed on T cells and Kv1.3 inhibitors suppress inflammation by these cells. As one measure of inflammation mediated by T cells, we examined the impact of OSK1 analogs on IL-2 and IFN-g production in human whole blood following addition of a pro-inflammatory stimulus (Tables 36-40 and Table 42). “WB/IL-2” in these tables refers to the assay measuring IL-2 response of whole blood (see, Example 46), whereas “WB/IFNg” refers to the assay measuring IFNg response of whole blood (see, Example 46). The IC50 values listed in Tables 36-40 and 42, represent the average IC50 value determined from experiments done with two or more blood donors. The whole blood assay (see Example 46) allows for a combined measurement of the potency of the analogs in blocking inflammation and Kv1.3, as well as an assessment of the stability of the molecules in a complex biological fluid. Using this assay, several OSK1 analogs were examined and found to potently suppress inflammation (
The solution NMR structure of OSK1 has been solved and is provided as pdb accession number “1SCO” in Entrez's Molecular Modeling Database (MMDB) [J. Chen et al. (2003) Nucleic Acids Res. 31, 474-7].
OSK1 analogs containing multiple amino acid changes were generated and their activity in the human whole blood assay of inflammation is provided in Table 42. Several analogs retain high potency in this assay despite as many as 12 amino acid changes. Based on the improved Kv1.3 selectivity of analogs with single amino acid changes, anologs with multiple amino acid changes may result in additional improvements in selectivity. It is also envisioned that analogs with multiple amino acid changes may have improved activity or stability in vivo, alone or in the context of a peptide conjugate to a half-life prolonging moiety.
Kv1.3 peptide toxins conjugated to half-life prolonging moieties are provided within this application. The bioactivity of several toxin conjugates is described in Table 43. OSK1 analogs with a N-terminal half-life prolonging 20K PEG moiety (see Example 48) were found to provide potent suppression of the whole blood IL-2 (“WB/IL-2”) and IFNg (“WB/IFNg”) response (Table 43). The 20K PEG-ShK conjugate, shown earlier to have prolonged half-life in vivo (see Examples 44 and 48), was also highly active in this whole blood assay. The FcLoop-OSK1 conjugates (see Example 49) were highly active in blocking inflammation (Table 43), and the CH2-OSK1 or PEG-CH2-OSK1 conjugates (see Example 54) provided modest blockade of the whole blood cytokine response (Table 43). The IL-2 and IFNg cytokine response measured in this whole blood assay results from T cell activation. Since this cytokine response is Kv1.3 dependent and potently blocked by the Kv1.3 peptide and peptide-conjugate inhibitors described herein, these whole blood studies illustrate the therapeutic utility of these molecules in treatment of immune disorders.
There may be pharmacokinetic or other reasons, in some cases, to prefer a monovalent dimeric Fc-toxin peptide fusion (as represented schematically in
A number of other exemplary ways that a monovalent dimeric Fc-toxin peptide fusion can be produced with greater efficiency are provided here, including for the production of monovalent dimeric Fc-OSK1 peptide analog fusions:
(1) Co-expressing equal amounts of Fc and Fc-toxin peptide in the same cells (e.g. mammalian cells). With the appropriate design, a mixture of bivalent dimeric Fc-toxin peptide fusion, monovalent dimeric Fc-toxin peptide fusion and dimeric Fc will be produced and released into the conditioned media. The monovalent dimeric Fc-toxin peptide can be purified from the mixture using conventional purification methods, for example, methods described in Examples 1, 2, and 41 herein.
(2) Engineering and recombinantly expressing in mammalian cells a single polypeptide construct represented by the following schematic:
Signal peptide-Fc-furin cleavage site-linker-furin cleavage site-Fc-toxin peptide
Furin cleavage occurs as the molecule travels through the endoplasmic reticulum and the intra-molecular Fc pairing (resulting in monovalent dimeric Fc-toxin peptide fusion) can occur preferentially to intermolecular Fc pairing (resulting in dimeric Fc-toxin peptide being expressed into conditioned medium;
By way of example of method (2) above, a DNA construct was produced for recombinant expression in mammalian cells of the following schematic polypeptide construct:
Signal peptide-Fc-furin cleavage site-linker-furin cleavage site-Fc-ShK(2-35)
The DNA construct had the following nucleotide coding sequence:
The resulting expressed polypeptide (from vector pTT5-Fc-Fc-L10-Shk(2-35)) had the following amino acid sequence before furin cleavage (the first 19 residues are a signal peptide sequence; furin cleavage sites are underlined):
(3) Similar to (2) above, a Fc-toxin peptide fusion monomer can be conjugated with an immunoglobulin light chain and heavy chain resulting in a monovalent chimeric immunoglobulin-Fc-toxin peptide molecule. We have termed an immunoglobulin (light chain+heavy chain)-Fc construct a “hemibody”; such “hemibodies” containing a dimeric Fc portion can provide the long half-life typical of a dimeric antibody. The schematic representation in
If the antibody chosen is a target specific antibody (e.g., an anti-Kv1.3 or anti-IKCa1 antibody), the chimeric molecule may also enhance the targeting efficiency of the toxin peptide.
[Dp(AOA)-PEG)4]Osk1 Peptide Synthesis of reduced [Dpr(AOA)4]Osk1. [Dpr(AOA)4]Osk1, having the sequence:
can be synthesized in a stepwise manner on a Symphony™ multi-peptide synthesizer by solid-phase peptide synthesis (SPPS) using 2-(1H-benzotriazole-1-yl)-1,1,3,3-tetramethyluronium hexafluorophosphate (HBTU)/N-methyl morpholine (NMM)/N,N-dimethyl-formamide (DMF) coupling chemistry at 0.1 mmol equivalent resin scale on Fmoc-Lys(Boc)-Wang resin (Novabiochem). N-alpha-(9-fluorenylmethyloxycarbonyl)- and side-chain protected amino acids can be purchased from Novabiochem. The following side-chain protection strategy can be employed: Asp(OtBu), Arg(Pbf), Cys(Trt), Gln(Trt), His(Trt), Lys(Nε-Boc), Ser(OtBu), Thr(OtBu) and Tyr(OtBu). Dpr(AOA), i.e., N-α-Fmoc-N-b-(N-t.-Boc-amino-oxyacetyl)-L-diaminopropionic acid, can be purchased from Novabiochem (Cat. No. 04-12-1185). The protected amino acid derivatives (20 mmol) can be dissolved in 100 ml 20% dimethyl sulfoxide (DMSO) in DMF (v/v). Protected amino acids can be activated with 200 mM HBTU, 400 mM NMM in 20% DMSO in DMF, and coupling can be carried out using two treatments with 0.5 mmol protected amino acid, 0.5 mmol HBTU, 1 mmol NMM in 20% DMF/DMSO for 25 minutes and then 40 minutes. Fmoc deprotection reactions can be carried out with two treatments using a 20% piperidine in DMF (v/v) solution for 10 minutes then 15 minutes. Following synthesis and removal of the N-terminal Fmoc group, the resin can be then drained, and washed with DCM, DMF, DCM, and then dried in vacuo. The peptide-resin can be deprotected and released from the resin by treatment with a TFA/amionooxyacetic acid/TIS/EDT/H2O (90:2.5:2.5:2.5:2.5) solution at room temperature for 1 hour. The volatiles can be then removed with a stream of nitrogen gas, the crude peptide precipitated twice with cold diethyl ether and collected by centrifugation. The [Dpr(AOA)4]Osk1 peptide can be then analyzed on a Waters 2795 analytical RP-HPLC system using a linear gradient (0-60% buffer B in 12 minutes, A: 0.1% TFA in water also containing 0.1% aminooxyacetic acid, B: 0.1% TFA in acetonitrile) on a Jupiter 4 μm Proteo™ 90 Å column.
Reversed-Phase HPLC Purification. Preparative Reversed-phase high-performance liquid chromatography can be performed on C18, 5 μm, 2.2 cm×25 cm) column. The [Dpr(AOA)4]Osk1 peptide is dissolved in 50% aqueous acetronitrile containing acetic acid and amionooxyacetic acid and loaded onto a preparative HPLC column. Chromatographic separations can be achieved using linear gradients of buffer B in A (A=0.1% aqueous TFA; B=90% aq. ACN containing 0.09% TFA), typically 5-95% over 90 minutes at 15 mL/min. Preparative HPLC fractions can be characterized by ESMS and photodiode array (PDA) HPLC, combined and lyophilized.
Osk1 peptide analog PEGylated at residue 4 by oxime formation: [Dpr(AOA)-PEG)4]Osk1 (i.e., GVI[Dpr(AOA-PEG)]NVKCKISRQCLEPCKKAGMRFGKCMNGKCHCTPK//SEQ ID NO:5010) can be made as follows. Lyophilized [Dpr(AOA)4]Osk1 peptide can be dissolved in 50% HPLC buffer A/B (5 mg/mL) and added to a two-fold molar excess of MeO-PEG-aldehyde, CH3O—[CH2CH2O]n—CH2CH2CHO (average molecular weight 20 kDa). The aminoxyacetyl group within the peptide at residue 4 reacts with the aldehyde group of the PEG to form a covalent oxime linkage. The reaction can be left for 24 hours, and can be analyzed on an Agilent™ 1100 RP-HPLC system using Zorbax™ 300SB-C8 5 μm column at 40° C. with a linear gradient (6-60% B in 16 minutes, A: 0.1% TFA in water, B: 0.1% TFA/90% ACN in water). Mono PEGylated [Dpr(AOA)-PEG)4]Osk1 peptide can be then isolated using a HiTrap™ 5 mL SP HP cation exchange column on AKTA FPLC system at 4° C. at 1 mL/min using a gradient of 0-50% B in 25 column volumes (Buffers: A=20 mM sodium acetate pH 4.0, B=1 M NaCl, 20 mM sodium acetate, pH 4.0). The fractions can be analyzed using a 4-20 tris-Gly SDS-PAGE gel and RP-HPLC. SDS-PAGE gels can be run for 1.5 hours at 125 V, 35 mA, 5 W. Pooled product, mono-PEGylated [Dpr(AOA)-PEG)4]Osk1 peptide, can be then dialyzed at 4° C. in 3 changes of 1 L of A4S buffer (10 mM NaOAc, 5% sorbitol, pH 4.0). The dialyzed product can be then concentrated in 10 K microcentrifuge filter to 2 mL volume and sterile-filtered using 0.2 μM syringe filter to give the final product.
Folding of [Dpr(AOA)-PEG)4]Osk1 (Disulphide bond formation). The mono-PEGylated [Dpr(AOA)-PEG)4]Osk1 peptide can be dissolved in 20% AcOH in water (v/v) and can be then diluted with water to a concentration of approximately 0.15 mg peptide mL, the pH adjusted to about 8.0 using NH4OH (28-30%), and gently stirred at room temperature for 36 hours. Folding process can be monitored by LC-MS analysis. Following this, folded mono-PEGylated [Dpr(AOA)-PEG)4]Osk1 can be purified using by reversed phase HPLC using a 1″ Luna 5 μm C18 100 Å Proteo™ column with a linear gradient 0-40% buffer B in 120 min (A=0.1% TFA in water, B=0.1% TFA in acetonitrile). Mono-PEGylated (oximated) [Dpr(AOA)-PEG)4]Osk1 peptide disulfide connectivity can be C1-C4, C2-C5, and C3-C6.
Abbreviations used throughout this specification are as defined below, unless otherwise defined in specific circumstances.
Ac acetyl (used to refer to acetylated residues)
AcBpa acetylated p-benzoyl-L-phenylalanine
ADCC antibody-dependent cellular cytotoxicity
Aib aminoisobutyric acid
bA beta-alanine
Bpa p-benzoyl-L-phenylalanine
BrAc bromoacetyl (BrCH2C(O)
BSA Bovine serum albumin
Bzl Benzyl
Cap Caproic acid
COPD Chronic obstructive pulmonary disease
CTL Cytotoxic T lymphocytes
DCC Dicylcohexylcarbodiimide
Dde 1-(4,4-dimethyl-2,6-dioxo-cyclohexylidene)ethyl
ESI-MS Electron spray ionization mass spectrometry
Fmoc fluorenylmethoxycarbonyl
HOBt 1-Hydroxybenzotriazole
HPLC high performance liquid chromatography
HSL homoserine lactone
IB inclusion bodies
KCa calcium-activated potassium channel (including IKCa, BKCa, SKCa)
Kv voltage-gated potassium channel
Lau Lauric acid
LPS lipopolysaccharide
LYMPH lymphocytes
MALDI-MS Matrix-assisted laser desorption ionization mass spectrometry
Me methyl
MeO methoxy
MHC major histocompatibility complex
MMP matrix metalloproteinase
1-Nap 1-napthylalanine
NEUT neutrophils
Nle norleucine
NMP N-methyl-2-pyrrolidinone
PAGE polyacrylamide gel electrophoresis
PBMC peripheral blood mononuclear cell
PBS Phosphate-buffered saline
Pbf 2,2,4,6,7-pendamethyldihydrobenzofuran-5-sulfonyl
PCR polymerase chain reaction
Pec pipecolic acid
PEG Poly(ethylene glycol)
pGlu pyroglutamic acid
Pic picolinic acid
pY phosphotyrosine
RBS ribosome binding site
RT room temperature (25° C.)
Sar sarcosine
SDS sodium dodecyl sulfate
STK serine-threonine kinases
t-Boc tert-Butoxycarbonyl
tBu tert-Butyl
THF thymic humoral factor
Trt trityl
This application claims priority from U.S. Provisional Application No. 60/854,674, filed Oct. 25, 2006, and U.S. Application No. 60/995,370, filed Sep. 25, 2007, both of which are hereby incorporated by reference. This application is related to U.S. Non-provisional application Ser. No. ______, filed Oct. 25, 2007, U.S. Non-provisional application Ser. No. ______, filed Oct. 25, 2007, U.S. Non-provisional application Ser. No. ______, filed Oct. 25, 2007, U.S. Non-provisional application Ser. No. ______, filed Oct. 25, 2007, and U.S. Non-provisional application Ser. No. ______, filed Oct. 25, 2007, all which applications are hereby incorporated by reference. This application is also related to U.S. Non-provisional application Ser. No. 11/584,177, filed Oct. 19, 2006, which claims priority from U.S. Provisional Application No. 60/729,083, filed Oct. 21, 2005, both of which applications are hereby incorporated by reference. The instant application contains a “lengthy” Sequence Listing which has been submitted via CD-R in lieu of a printed paper copy in accordance with 37 C.F.R. Section 1.821, and is hereby incorporated by reference in its entirety. Three copies of said CD-R, recorded on Oct. 18, 2007 are labeled CRF, “Copy 1” and “Copy 2”, respectively, and each contains only one identical 2.60 Mb file (A-1186-US-NP5 SeqList.txt). Throughout this application various publications are referenced within parentheses or brackets. The disclosures of these publications in their entireties are hereby incorporated by reference in this application in order to more fully describe the state of the art to which this invention pertains.
| Number | Date | Country | |
|---|---|---|---|
| 60854674 | Oct 2006 | US | |
| 60995370 | Sep 2007 | US |
