Patent Grant
11497798
The present invention provides engineered human alpha-galactosidase polypeptides and compositions thereof. The engineered human alpha-galactosidase polypeptides have been optimized to provide improved stability under both acidic (pH<4.5) and basic (pH>7) conditions. The invention also relates to the use of the compositions comprising the engineered human alpha-galactosidase polypeptides for therapeutic purposes.
The official copy of the Sequence Listing is submitted concurrently with the specification as an ASCII formatted text file via EFS-Web, with a file name of “CX7-147WO2UC1_ST25.txt”, a creation date of Aug. 4, 2020, and a size of 2,545,695 bytes. The Sequence Listing filed via EFS-Web is part of the specification and is incorporated in its entirety by reference herein.
Human alpha galactosidase (“GLA”; EC 3.2.1.22) is a lysosomal glycoprotein responsible for hydrolyzing terminal alpha galactosyl moieties from glycolipids and glycoproteins. It works on many substrates present in a range of human tissues. Fabry disease (also referred to as angiokeratoma corporis diffusum, Anderson-Fabry disease, hereditary dystopic lipidosis, alpha-galactosidase A deficiency, GLA deficiency, and ceramide trihexosidase deficiency) is an X-linked inborn error of glycosphingolipid catabolism that results from deficient or absent activity of alpha-galactosidase A. Patients affected with Fabry disease accumulate globotriosylceramide (Gb3) and related glycosphingolipids in the plasma and cellular lysosomes of blood vessels, tissue and organs (See e.g., Nance et al., Arch. Neurol., 63:453-457 [2006]). As the patient ages, the blood vessels become progressively narrowed, due to the accumulation of these lipids, resulting in decreased blood flow and nourishment to the tissues, particularly in the skin, kidneys, heart, brain, and nervous system. Thus, Fabry disease is a systemic disorder that manifests as renal failure, cardiac disease, cerebrovascular disease, small-fiber peripheral neuropathy, and skin lesions, as well as other disorders (See e.g., Schiffmann, Pharm. Ther., 122:65-77 [2009]). Affected patients exhibit symptoms such as painful hands and feet, clusters of small, dark red spots on their skin, the decreased ability to sweat, corneal opacity, gastrointestinal issues, tinnitus, and hearing loss. Potentially life-threatening complications include progressive renal damage, heart attacks, and stroke. This disease affects an estimated 1 in 40,000-60,000 males, but also occurs in females. Indeed, heterozygous women with Fabry disease experience significant life-threatening conditions requiring medical treatment, including nervous system abnormalities, chronic pain, fatigue, high blood pressure, heart disease, kidney failure, and stroke (See e.g., Want et al., Genet. Med., 13:457-484 [2011]). Signs of Fabry disease can start any time from infancy on, with signs usually beginning to show between ages 4 and 8, although some patients exhibit a milder, late-onset disease. Treatment is generally supportive and there is no cure for Fabry disease, thus there remains a need for a safe and effective treatment.
The present invention provides engineered human alpha-galactosidase polypeptides and compositions thereof. The engineered human alpha-galactosidase polypeptides have been optimized to provide improved stability under both acidic (pH<4.5) and basic (pH>7) conditions. The invention also relates to the use of the compositions comprising the engineered human alpha-galactosidase polypeptides for therapeutic purposes.
The present invention provides recombinant alpha galactosidase A and/or biologically active recombinant alpha galactosidase A fragment comprising an amino acid sequence comprising at least about 70%, at least about 75%, at least about 80%, at least about 85%, at least about 90%, at least about 91%, at least about 92%, at least about 93%, at least about 94%, at least about 95%, at least about 96%, at least about 97%, at least about 98%, or at least about 99% sequence identity to SEQ ID NO:5. In some embodiments, the alpha galactosidase A comprises at least one mutation in at least one position as provided in Tables 2.1, 2.2, 2.4, and/or 2.5, wherein the positions are numbered with reference to SEQ ID NO:5. In some embodiments, the alpha galactosidase A comprises at least one mutation in at least one position as provided in Table 2.3, wherein the positions are numbered with reference to SEQ ID NO:10. In some additional embodiments, the recombinant alpha galactosidase A is derived from a human alpha galactosidase A. In some further embodiments, the recombinant alpha galactosidase A comprises the polypeptide sequence of SEQ ID NO:15, 13, 10, or 18. In still some additional embodiments, the recombinant alpha galactosidase A is more thermostable than the alpha galactosidase A of SEQ ID NO:5. In some further embodiments, the recombinant alpha galactosidase A is more stable at pH 7.4 than the alpha galactosidase A of SEQ ID NO:5, while in additional embodiments, the recombinant alpha galactosidase A is more stable at pH 4.3 than the alpha galactosidase A of SEQ ID NO:5. In some embodiments the recombinant alpha galactosidase A is more stable at pH 7.4 and pH 4.3 than the alpha galactosidase A of SEQ ID NO:5. In still some further embodiments, the recombinant alpha galactosidase A is a deimmunized alpha galactosidase A. In some embodiments, the recombinant alpha galactosidase A is a deimmunized alpha galactosidase A provided in Table 7.1. In still some additional embodiments, the recombinant alpha galactosidase A is purified. In some embodiments, the recombinant alpha galactosidase A exhibits at least one improved property selected from: i) enhanced catalytic activity; ii) increased tolerance to pH 7.4; iii) increased tolerance to pH 4.3; or iv) reduced immunogenicity; or a combination of any of i), ii), iii), or iv), as compared to a reference sequence. In some embodiments, the reference sequence is SEQ ID NO:5, while in some alternative embodiments, the reference sequence is SEQ ID NO:10.
The present invention also provides recombinant polynucleotide sequences encoding at least one recombinant alpha galactosidase A as provided herein (e.g., Tables 2.1, 2.2, 2.3, 2.4, 2.5, and/or Table 7.1). In some embodiments, the recombinant polynucleotide sequence is codon-optimized.
The present invention also provides expression vectors comprising the recombinant polynucleotide sequence encoding at least one recombinant alpha galactosidase A as provided herein (e.g., Tables 2.1, 2.2, 2.3, 2.4, 2.5, and/or Table 7.1). In some embodiments, the recombinant polynucleotide sequence is operably linked to a control sequence. In some additional embodiments, the control sequence is a promoter. In some further embodiments, the promoter is a heterologous promoter. In some embodiments, the expression vector further comprises a signal sequence, as provided herein.
The present invention also provides host cells comprising at least one expression vector as provided herein. In some embodiments, the host cell comprises an expression vector comprising the recombinant polynucleotide sequence encoding at least one recombinant alpha galactosidase A as provided herein (e.g., Tables 2.1, 2.2, 2.3, 2.4, 2.5, and/or Table 7.1). In some embodiments, the host cell is eukaryotic.
The present invention also provides methods of producing an alpha galactosidase A variant, comprising culturing a host cell provided herein, under conditions that the alpha galactosidase A encoded by the recombinant polynucleotide is produced. In some embodiments, the methods further comprise the step of recovering alpha galactosidase A. In some further embodiments, the methods further comprise the step of purifying the alpha galactosidase A.
The present invention also provides compositions comprising at least one recombinant alpha galactosidase A as provided herein (e.g., Tables 2.1, 2.2, 2.3, 2.4, 2.5, and/or Table 7.1). In some embodiments, the present invention provides pharmaceutical compositions. In some additional embodiments, the present invention provides pharmaceutical compositions for the treatment of Fabry disease, comprising an enzyme composition provided herein. In some embodiments, the pharmaceutical compositions, further comprise a pharmaceutically acceptable carrier and/or excipient. In some additional embodiments, the pharmaceutical composition is suitable for parenteral injection or infusion to a human.
The present invention also provides methods for treating and/or preventing the symptoms of Fabry disease in a subject, comprising providing a subject having Fabry disease, and providing at least one pharmaceutical composition compositions comprising at least one recombinant alpha galactosidase A as provided herein (e.g., Tables 2.1, 2.2, 2.3, 2.4, 2.5, and/or Table 7.1), and administering the pharmaceutical composition to the subject. In some embodiments, the symptoms of Fabry disease are ameliorated in the subject. In some additional embodiments, the subject to whom the pharmaceutical composition of the present invention has been administered is able to eat a diet that is less restricted in its fat content than diets required by subjects exhibiting the symptoms of Fabry disease. In some embodiments, the subject is an infant or child, while in some alternative embodiments, the subject is an adult or young adult.
The present invention also provides for the use of the compositions provided herein.
The present invention provides engineered human alpha-galactosidase polypeptides and compositions thereof. The engineered human alpha-galactosidase polypeptides have been optimized to provide improved stability under both acidic (pH<4.5) and basic (pH>7) conditions. The invention also relates to the use of the compositions comprising the engineered human alpha-galactosidase polypeptides for therapeutic purposes.
In some embodiments, the engineered human alpha-galactosidase polypeptides have been optimized to provide improved stability at various levels. The invention also relates to the use of the compositions comprising the engineered human alpha-galactosidase polypeptides for therapeutic purposes.
Enzyme replacement therapy for treatment of Fabry disease (e.g., Fabrazyme® agalsidase beta; Genzyme) is available and is considered for eligible individuals. Currently used enzyme replacements therapies are recombinantly expressed forms of the wild-type human GLA. It is known that intravenously administered GLA circulates, becomes endocytosed, and travels to the endosomes/lysosomes of target organs, where it reduces the accumulation of Gb3. These drugs do not completely relieve patient symptoms, as neuropathic pain and transient ischemic attacks continue to occur at reduced rates. In addition, the uptake of GLA by most target organs is poor in comparison to the liver, and the enzyme is unstable at the pH of blood and lysosomes. Thus, issues remain with available treatments. In addition, patients may develop an immune response (IgG and IgE antibodies targeting the administered drug), and suffer severe allergic (anaphylactic) reactions, severe infusion reactions, and even death. The present invention is intended to provide more stable enzymes suitable for treatment of Fabry disease, yet with reduced side effects and improved outcomes, as compared to currently available treatments. Indeed, the present invention is intended to provide recombinant GLA enzymes that have increased stability in blood (pH 7.4), which the enzyme encounters upon injection into the bloodstream. In addition, the enzyme has increased stability at the pH of the lysosome (pH 4.3), the location where the enzyme is active during therapy. Thus, directed evolution of recombinantly expressed human GLA in Saccharomyces cerevisiae, employing high throughput screening of diverse enzyme variant libraries, was used to provide novel GLA variants with desired stability properties. In addition, variant enzymes were screened and their amino acid sequence determined in order to identify novel GLA variants with a predicted reduced immunogenicity. By providing GLA variants with increased pH stability and reduced immunogenicity, the present invention provides compositions and methods suitable for use in patients by increasing patient tolerance of treatment and providing flexibility in dosing and formulation for improved patient outcomes.
Unless defined otherwise, all technical and scientific terms used herein generally have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. Generally, the nomenclature used herein and the laboratory procedures of cell culture, molecular genetics, microbiology, biochemistry, organic chemistry, analytical chemistry and nucleic acid chemistry described below are those well-known and commonly employed in the art. Such techniques are well-known and described in numerous texts and reference works well known to those of skill in the art. Standard techniques, or modifications thereof, are used for chemical syntheses and chemical analyses. All patents, patent applications, articles and publications mentioned herein, both supra and infra, are hereby expressly incorporated herein by reference.
Although any suitable methods and materials similar or equivalent to those described herein find use in the practice of the present invention, some methods and materials are described herein. It is to be understood that this invention is not limited to the particular methodology, protocols, and reagents described, as these may vary, depending upon the context they are used by those of skill in the art. Accordingly, the terms defined immediately below are more fully described by reference to the application as a whole. All patents, patent applications, articles and publications mentioned herein, both supra and infra, are hereby expressly incorporated herein by reference.
Also, as used herein, the singular “a”, “an,” and “the” include the plural references, unless the context clearly indicates otherwise.
Numeric ranges are inclusive of the numbers defining the range. Thus, every numerical range disclosed herein is intended to encompass every narrower numerical range that falls within such broader numerical range, as if such narrower numerical ranges were all expressly written herein. It is also intended that every maximum (or minimum) numerical limitation disclosed herein includes every lower (or higher) numerical limitation, as if such lower (or higher) numerical limitations were expressly written herein.
The term “about” means an acceptable error for a particular value. In some instances “about” means within 0.05%, 0.5%, 1.0%, or 2.0%, of a given value range. In some instances, “about” means within 1, 2, 3, or 4 standard deviations of a given value.
Furthermore, the headings provided herein are not limitations of the various aspects or embodiments of the invention which can be had by reference to the application as a whole. Accordingly, the terms defined immediately below are more fully defined by reference to the application as a whole. Nonetheless, in order to facilitate understanding of the invention, a number of terms are defined below.
Unless otherwise indicated, nucleic acids are written left to right in 5′ to 3′ orientation; amino acid sequences are written left to right in amino to carboxy orientation, respectively.
As used herein, the term “comprising” and its cognates are used in their inclusive sense (i.e., equivalent to the term “including” and its corresponding cognates).
“EC” number refers to the Enzyme Nomenclature of the Nomenclature Committee of the International Union of Biochemistry and Molecular Biology (NC-IUBMB). The IUBMB biochemical classification is a numerical classification system for enzymes based on the chemical reactions they catalyze.
“ATCC” refers to the American Type Culture Collection whose biorepository collection includes genes and strains.
“NCBI” refers to National Center for Biological Information and the sequence databases provided therein.
“Protein,” “polypeptide,” and “peptide” are used interchangeably herein to denote a polymer of at least two amino acids covalently linked by an amide bond, regardless of length or post-translational modification (e.g., glycosylation or phosphorylation).
“Amino acids” are referred to herein by either their commonly known three-letter symbols or by the one-letter symbols recommended by IUPAC-IUB Biochemical Nomenclature Commission. Nucleotides, likewise, may be referred to by their commonly accepted single letter codes.
The term “engineered,” “recombinant,” “non-naturally occurring,” and “variant,” when used with reference to a cell, a polynucleotide or a polypeptide refers to a material or a material corresponding to the natural or native form of the material that has been modified in a manner that would not otherwise exist in nature or is identical thereto but produced or derived from synthetic materials and/or by manipulation using recombinant techniques.
As used herein, “wild-type” and “naturally-occurring” refer to the form found in nature. For example a wild-type polypeptide or polynucleotide sequence is a sequence present in an organism that can be isolated from a source in nature and which has not been intentionally modified by human manipulation.
“Deimmunized” as used herein, refers to the manipulation of a protein sequence to create a variant that is predicted to be not as immunogenic as the wild-type or reference protein. In some embodiments, the predicted deimmunization is complete, in that the variant protein is predicted to not stimulate an immune response in patients to whom the variant protein is administered. This response can be measured by various methods including but not limited to, the presence or abundance of anti-drug antibodies, the presence or abundance of neutralizing antibodies, the presence of an anaphylactic response, peptide presentation on major histocompatibility complex-II (MHC-II) proteins, or the prevalence or intensity of cytokine release upon administration of the protein. In some embodiments, the variant protein is less immunogenic than the wild-type or reference protein. In some embodiments, deimmunization involves modifications to subsequences of proteins (e.g., epitopes) that are recognized by human leukocyte antigen (HLA) receptors. In some embodiments, these epitopes are removed by changing their amino acid sequences to produce a deimmunized variant protein in which such subsequences are no longer recognized by the HLA receptors. In some other embodiments, these epitopes retain binding affinity to HLA receptors, but are not presented. In some embodiments, the deimmunized protein shows lower levels of response in biochemical and cell-biological predictors of human immunological responses including dendritic-cell T-cell activation assays, or (HLA) peptide binding assays. In some embodiments, these epitopes are removed by changing their amino acid sequence to produce a deimmunized variant protein in which the epitopes are no longer recognized by T-cell receptors. In still other embodiments the deimmunized protein induces anergy in its corresponding T-cells, activates T regulatory cells, or results in clonal deletion of recognizing B-cells.
“Coding sequence” refers to that part of a nucleic acid (e.g., a gene) that encodes an amino acid sequence of a protein.
The term “percent (%) sequence identity” is used herein to refer to comparisons among polynucleotides and polypeptides, and are determined by comparing two optimally aligned sequences over a comparison window, wherein the portion of the polynucleotide or polypeptide sequence in the comparison window may comprise additions or deletions (i.e., gaps) as compared to the reference sequence for optimal alignment of the two sequences. The percentage may be calculated by determining the number of positions at which the identical nucleic acid base or amino acid residue occurs in both sequences to yield the number of matched positions, dividing the number of matched positions by the total number of positions in the window of comparison and multiplying the result by 100 to yield the percentage of sequence identity. Alternatively, the percentage may be calculated by determining the number of positions at which either the identical nucleic acid base or amino acid residue occurs in both sequences or a nucleic acid base or amino acid residue is aligned with a gap to yield the number of matched positions, dividing the number of matched positions by the total number of positions in the window of comparison and multiplying the result by 100 to yield the percentage of sequence identity. Those of skill in the art appreciate that there are many established algorithms available to align two sequences. Optimal alignment of sequences for comparison can be conducted, e.g., by the local homology algorithm of Smith and Waterman (Smith and Waterman, Adv. Appl. Math., 2:482 [1981]), by the homology alignment algorithm of Needleman and Wunsch (Needleman and Wunsch, J. Mol. Biol., 48:443 [1970), by the search for similarity method of Pearson and Lipman (Pearson and Lipman, Proc. Natl. Acad. Sci. USA 85:2444 [1988]), by computerized implementations of these algorithms (e.g., GAP, BESTFIT, FASTA, and TFASTA in the GCG Wisconsin Software Package), or by visual inspection, as known in the art. Examples of algorithms that are suitable for determining percent sequence identity and sequence similarity include, but are not limited to the BLAST and BLAST 2.0 algorithms, which are described by Altschul et al. (See, Altschul et al., J. Mol. Biol., 215: 403-410 [1990]; and Altschul et al., 1977, Nucleic Acids Res., 3389-3402 [1977], respectively). Software for performing BLAST analyses is publicly available through the National Center for Biotechnology Information website. This algorithm involves first identifying high scoring sequence pairs (HSPs) by identifying short words of length W in the query sequence, which either match or satisfy some positive-valued threshold score T when aligned with a word of the same length in a database sequence. T is referred to as, the neighborhood word score threshold (See, Altschul et al, supra). These initial neighborhood word hits act as seeds for initiating searches to find longer HSPs containing them. The word hits are then extended in both directions along each sequence for as far as the cumulative alignment score can be increased. Cumulative scores are calculated using, for nucleotide sequences, the parameters M (reward score for a pair of matching residues; always >0) and N (penalty score for mismatching residues; always <0). For amino acid sequences, a scoring matrix is used to calculate the cumulative score. Extension of the word hits in each direction are halted when: the cumulative alignment score falls off by the quantity X from its maximum achieved value; the cumulative score goes to zero or below, due to the accumulation of one or more negative-scoring residue alignments; or the end of either sequence is reached. The BLAST algorithm parameters W, T, and X determine the sensitivity and speed of the alignment. The BLASTN program (for nucleotide sequences) uses as defaults a wordlength (W) of 11, an expectation (E) of 10, M=5, N=−4, and a comparison of both strands. For amino acid sequences, the BLASTP program uses as defaults a wordlength (W) of 3, an expectation (E) of 10, and the BLOSUM62 scoring matrix (See, Henikoff and Henikoff, Proc. Natl. Acad. Sci. USA 89:10915 [1989]). Exemplary determination of sequence alignment and % sequence identity can employ the BESTFIT or GAP programs in the GCG Wisconsin Software package (Accelrys, Madison Wis.), using default parameters provided.
“Reference sequence” refers to a defined sequence used as a basis for a sequence comparison. A reference sequence may be a subset of a larger sequence, for example, a segment of a full-length gene or polypeptide sequence. Generally, a reference sequence is at least 20 nucleotide or amino acid residues in length, at least 25 residues in length, at least 50 residues in length, at least 100 residues in length or the full length of the nucleic acid or polypeptide. Since two polynucleotides or polypeptides may each (1) comprise a sequence (i.e., a portion of the complete sequence) that is similar between the two sequences, and (2) may further comprise a sequence that is divergent between the two sequences, sequence comparisons between two (or more) polynucleotides or polypeptide are typically performed by comparing sequences of the two polynucleotides or polypeptides over a “comparison window” to identify and compare local regions of sequence similarity. In some embodiments, a “reference sequence” can be based on a primary amino acid sequence, where the reference sequence is a sequence that can have one or more changes in the primary sequence. “Comparison window” refers to a conceptual segment of at least about 20 contiguous nucleotide positions or amino acids residues wherein a sequence may be compared to a reference sequence of at least 20 contiguous nucleotides or amino acids and wherein the portion of the sequence in the comparison window may comprise additions or deletions (i.e., gaps) of 20 percent or less as compared to the reference sequence (which does not comprise additions or deletions) for optimal alignment of the two sequences. The comparison window can be longer than 20 contiguous residues, and includes, optionally 30, 40, 50, 100, or longer windows.
“Corresponding to”, “reference to” or “relative to” when used in the context of the numbering of a given amino acid or polynucleotide sequence refers to the numbering of the residues of a specified reference sequence when the given amino acid or polynucleotide sequence is compared to the reference sequence. In other words, the residue number or residue position of a given polymer is designated with respect to the reference sequence rather than by the actual numerical position of the residue within the given amino acid or polynucleotide sequence. For example, a given amino acid sequence, such as that of an engineered GLA, can be aligned to a reference sequence by introducing gaps to optimize residue matches between the two sequences. In these cases, although the gaps are present, the numbering of the residue in the given amino acid or polynucleotide sequence is made with respect to the reference sequence to which it has been aligned.
“Amino acid difference” or “residue difference” refers to a difference in the amino acid residue at a position of a polypeptide sequence relative to the amino acid residue at a corresponding position in a reference sequence. The positions of amino acid differences generally are referred to herein as “Xn,” where n refers to the corresponding position in the reference sequence upon which the residue difference is based. For example, a “residue difference at position X93 as compared to SEQ ID NO:2” refers to a difference of the amino acid residue at the polypeptide position corresponding to position 93 of SEQ ID NO:2. Thus, if the reference polypeptide of SEQ ID NO:2 has a serine at position 93, then a “residue difference at position X93 as compared to SEQ ID NO:2” an amino acid substitution of any residue other than serine at the position of the polypeptide corresponding to position 93 of SEQ ID NO:2. In most instances herein, the specific amino acid residue difference at a position is indicated as “XnY” where “Xn” specified the corresponding position as described above, and “Y” is the single letter identifier of the amino acid found in the engineered polypeptide (i.e., the different residue than in the reference polypeptide). In some instances (e.g., in Tables 2.1, 2.2, 2.3, 2.4, 2.5, and 6.1), the present disclosure also provides specific amino acid differences denoted by the conventional notation “AnB”, where A is the single letter identifier of the residue in the reference sequence, “n” is the number of the residue position in the reference sequence, and B is the single letter identifier of the residue substitution in the sequence of the engineered polypeptide. In some instances, a polypeptide of the present disclosure can include one or more amino acid residue differences relative to a reference sequence, which is indicated by a list of the specified positions where residue differences are present relative to the reference sequence. In some embodiments, where more than one amino acid can be used in a specific residue position of a polypeptide, the various amino acid residues that can be used are separated by a “/” (e.g., X307H/X307P or X307H/P). In some embodiments, the enzyme variants comprise more than one substitution. These substitutions are separated by a slash for ease in reading (e.g., C143A/K206A). The present application includes engineered polypeptide sequences comprising one or more amino acid differences that include either/or both conservative and non-conservative amino acid substitutions.
“Conservative amino acid substitution” refers to a substitution of a residue with a different residue having a similar side chain, and thus typically involves substitution of the amino acid in the polypeptide with amino acids within the same or similar defined class of amino acids. By way of example and not limitation, an amino acid with an aliphatic side chain may be substituted with another aliphatic amino acid (e.g., alanine, valine, leucine, and isoleucine); an amino acid with hydroxyl side chain is substituted with another amino acid with a hydroxyl side chain (e.g., serine and threonine); an amino acids having aromatic side chains is substituted with another amino acid having an aromatic side chain (e.g., phenylalanine, tyrosine, tryptophan, and histidine); an amino acid with a basic side chain is substituted with another amino acid with a basis side chain (e.g., lysine and arginine); an amino acid with an acidic side chain is substituted with another amino acid with an acidic side chain (e.g., aspartic acid or glutamic acid); and/or a hydrophobic or hydrophilic amino acid is replaced with another hydrophobic or hydrophilic amino acid, respectively.
“Non-conservative substitution” refers to substitution of an amino acid in the polypeptide with an amino acid with significantly differing side chain properties. Non-conservative substitutions may use amino acids between, rather than within, the defined groups and affects (a) the structure of the peptide backbone in the area of the substitution (e.g., proline for glycine) (b) the charge or hydrophobicity, or (c) the bulk of the side chain. By way of example and not limitation, an exemplary non-conservative substitution can be an acidic amino acid substituted with a basic or aliphatic amino acid; an aromatic amino acid substituted with a small amino acid; and a hydrophilic amino acid substituted with a hydrophobic amino acid.
“Deletion” refers to modification to the polypeptide by removal of one or more amino acids from the reference polypeptide. Deletions can comprise removal of 1 or more amino acids, 2 or more amino acids, 5 or more amino acids, 10 or more amino acids, 15 or more amino acids, or 20 or more amino acids, up to 10% of the total number of amino acids, or up to 20% of the total number of amino acids making up the reference enzyme while retaining enzymatic activity and/or retaining the improved properties of an engineered enzyme. Deletions can be directed to the internal portions and/or terminal portions of the polypeptide. In various embodiments, the deletion can comprise a continuous segment or can be discontinuous.
“Insertion” refers to modification to the polypeptide by addition of one or more amino acids from the reference polypeptide. Insertions can be in the internal portions of the polypeptide, or to the carboxy or amino terminus. Insertions as used herein include fusion proteins as is known in the art. The insertion can be a contiguous segment of amino acids or separated by one or more of the amino acids in the naturally occurring polypeptide.
A “functional fragment” or a “biologically active fragment” used interchangeably herein refers to a polypeptide that has an amino-terminal and/or carboxy-terminal deletion(s) and/or internal deletions, but where the remaining amino acid sequence is identical to the corresponding positions in the sequence to which it is being compared (e.g., a full-length engineered GLA of the present invention) and that retains substantially all of the activity of the full-length polypeptide.
“Isolated polypeptide” refers to a polypeptide which is substantially separated from other contaminants that naturally accompany it, e.g., protein, lipids, and polynucleotides. The term embraces polypeptides which have been removed or purified from their naturally-occurring environment or expression system (e.g., host cell or in vitro synthesis). The recombinant GLA polypeptides may be present within a cell, present in the cellular medium, or prepared in various forms, such as lysates or isolated preparations. As such, in some embodiments, the recombinant GLA polypeptides can be an isolated polypeptide.
“Substantially pure polypeptide” refers to a composition in which the polypeptide species is the predominant species present (i.e., on a molar or weight basis it is more abundant than any other individual macromolecular species in the composition), and is generally a substantially purified composition when the object species comprises at least about 50 percent of the macromolecular species present by mole or % weight. Generally, a substantially pure GLA composition comprises about 60% or more, about 70% or more, about 80% or more, about 90% or more, about 95% or more, and about 98% or more of all macromolecular species by mole or % weight present in the composition. In some embodiments, the object species is purified to essential homogeneity (i.e., contaminant species cannot be detected in the composition by conventional detection methods) wherein the composition consists essentially of a single macromolecular species. Solvent species, small molecules (<500 Daltons), and elemental ion species are not considered macromolecular species. In some embodiments, the isolated recombinant GLA polypeptides are substantially pure polypeptide compositions.
“Improved enzyme property” refers to an engineered GLA polypeptide that exhibits an improvement in any enzyme property as compared to a reference GLA polypeptide and/or as a wild-type GLA polypeptide or another engineered GLA polypeptide. Improved properties include but are not limited to such properties as increased protein expression, increased thermoactivity, increased thermostability, increased pH activity, increased stability, increased enzymatic activity, increased substrate specificity or affinity, increased specific activity, increased resistance to substrate or end-product inhibition, increased chemical stability, improved chemoselectivity, improved solvent stability, increased tolerance to acidic or basic pH, increased tolerance to proteolytic activity (i.e., reduced sensitivity to proteolysis), reduced aggregation, increased solubility, reduced immunogenicity, improved post-translational modification (e.g., glycosylation), and altered temperature profile.
“Increased enzymatic activity” or “enhanced catalytic activity” refers to an improved property of the engineered GLA polypeptides, which can be represented by an increase in specific activity (e.g., product produced/time/weight protein) or an increase in percent conversion of the substrate to the product (e.g., percent conversion of starting amount of substrate to product in a specified time period using a specified amount of GLA) as compared to the reference GLA enzyme. Exemplary methods to determine enzyme activity are provided in the Examples. Any property relating to enzyme activity may be affected, including the classical enzyme properties of Km, Vmax or kcat, changes of which can lead to increased enzymatic activity. Improvements in enzyme activity can be from about 1.1 fold the enzymatic activity of the corresponding wild-type enzyme, to as much as 2-fold, 5-fold, 10-fold, 20-fold, 25-fold, 50-fold, 75-fold, 100-fold, 150-fold, 200-fold or more enzymatic activity than the naturally occurring GLA or another engineered GLA from which the GLA polypeptides were derived.
In some embodiments, the engineered GLA polypeptides have a kcat of at least 0.1/sec, at least 0.5/sec, at least 1.0/sec, at least 5.0/sec, at least 10.0/sec and in some preferred embodiments greater than 10.0/sec. In some embodiments, the Km is in the range of about 1 μM to about 5 mM; in the range of about 5 μM to about 2 mM; in the range of about 10 μM to about 2 mM; or in the range of about 10 μM to about 1 mM. In some specific embodiments, the engineered GLA enzyme exhibits improved enzymatic activity after exposure to certain conditions in the range of 1.5 to 10 fold, 1.5 to 25 fold, 1.5 to 50 fold, 1.5 to 100 fold or greater than that of a reference GLA enzyme (e.g., a wild-type GLA or any other reference GLA). GLA activity can be measured by any suitable method known in the art (e.g., standard assays, such as monitoring changes in spectrophotometric properties of reactants or products). In some embodiments, the amount of products produced can be measured by High-Performance Liquid Chromatography (HPLC) separation combined with UV absorbance or fluorescent detection directly or following o-phthaldialdehyde (OPA) derivatization. Comparisons of enzyme activities are made using a defined preparation of enzyme, a defined assay under a set condition, and one or more defined substrates, as further described in detail herein. Generally, when lysates are compared, the numbers of cells and the amount of protein assayed are determined as well as use of identical expression systems and identical host cells to minimize variations in amount of enzyme produced by the host cells and present in the lysates.
The term “improved tolerance to acidic pH” means that a recombinant GLA according to the invention will have increased stability (higher retained activity at about pH 4.8 after exposure to acidic pH for a specified period of time (1 hour, up to 24 hours)) as compared to a reference GLA or another enzyme.
“Physiological pH” as used herein means the pH range generally found in a subject's (e.g., human) blood.
The term “basic pH” (e.g., used with reference to improved stability to basic pH conditions or increased tolerance to basic pH) means a pH range of about 7 to 11.
The term “acidic pH” (e.g., used with reference to improved stability to acidic pH conditions or increased tolerance to acidic pH) means a pH range of about 1.5 to 4.5.
“Conversion” refers to the enzymatic conversion (or biotransformation) of a substrate(s) to the corresponding product(s). “Percent conversion” refers to the percent of the substrate that is converted to the product within a period of time under specified conditions. Thus, the “enzymatic activity” or “activity” of a GLA polypeptide can be expressed as “percent conversion” of the substrate to the product in a specific period of time.
“Hybridization stringency” relates to hybridization conditions, such as washing conditions, in the hybridization of nucleic acids. Generally, hybridization reactions are performed under conditions of lower stringency, followed by washes of varying but higher stringency. The term “moderately stringent hybridization” refers to conditions that permit target-DNA to bind a complementary nucleic acid that has about 60% identity, preferably about 75% identity, about 85% identity to the target DNA, with greater than about 90% identity to target-polynucleotide. Exemplary moderately stringent conditions are conditions equivalent to hybridization in 50% formamide, 5× Denhart's solution, 5×SSPE, 0.2% SDS at 42° C., followed by washing in 0.2×SSPE, 0.2% SDS, at 42° C. “High stringency hybridization” refers generally to conditions that are about 10° C. or less from the thermal melting temperature Tm as determined under the solution condition for a defined polynucleotide sequence. In some embodiments, a high stringency condition refers to conditions that permit hybridization of only those nucleic acid sequences that form stable hybrids in 0.018 M NaCl at 65° C. (i.e., if a hybrid is not stable in 0.018 M NaCl at 65° C., it will not be stable under high stringency conditions, as contemplated herein). High stringency conditions can be provided, for example, by hybridization in conditions equivalent to 50% formamide, 5× Denhart's solution, 5×SSPE, 0.2% SDS at 42° C., followed by washing in 0.1×SSPE, and 0.1% SDS at 65° C. Another high stringency condition is hybridizing in conditions equivalent to hybridizing in 5×SSC containing 0.1% (w:v) SDS at 65° C. and washing in 0.1×SSC containing 0.1% SDS at 65° C. Other high stringency hybridization conditions, as well as moderately stringent conditions, are described in the references cited above.
“Codon optimized” refers to changes in the codons of the polynucleotide encoding a protein to those preferentially used in a particular organism such that the encoded protein is more efficiently expressed in the organism of interest. Although the genetic code is degenerate in that most amino acids are represented by several codons, called “synonyms” or “synonymous” codons, it is well known that codon usage by particular organisms is nonrandom and biased towards particular codon triplets. This codon usage bias may be higher in reference to a given gene, genes of common function or ancestral origin, highly expressed proteins versus low copy number proteins, and the aggregate protein coding regions of an organism's genome. In some embodiments, the polynucleotides encoding the GLA enzymes may be codon optimized for optimal production from the host organism selected for expression.
“Control sequence” refers herein to include all components, which are necessary or advantageous for the expression of a polynucleotide and/or polypeptide of the present application. Each control sequence may be native or foreign to the nucleic acid sequence encoding the polypeptide. Such control sequences include, but are not limited to, a leader, polyadenylation sequence, propeptide sequence, promoter sequence, signal peptide sequence, initiation sequence and transcription terminator. At a minimum, the control sequences include a promoter, and transcriptional and translational stop signals. The control sequences may be provided with linkers for the purpose of introducing specific restriction sites facilitating ligation of the control sequences with the coding region of the nucleic acid sequence encoding a polypeptide.
“Operably linked” is defined herein as a configuration in which a control sequence is appropriately placed (i.e., in a functional relationship) at a position relative to a polynucleotide of interest such that the control sequence directs or regulates the expression of the polynucleotide and/or polypeptide of interest.
“Promoter sequence” refers to a nucleic acid sequence that is recognized by a host cell for expression of a polynucleotide of interest, such as a coding sequence. The promoter sequence contains transcriptional control sequences, which mediate the expression of a polynucleotide of interest. The promoter may be any nucleic acid sequence which shows transcriptional activity in the host cell of choice including mutant, truncated, and hybrid promoters, and may be obtained from genes encoding extracellular or intracellular polypeptides either homologous or heterologous to the host cell.
“Suitable reaction conditions” refers to those conditions in the enzymatic conversion reaction solution (e.g., ranges of enzyme loading, substrate loading, temperature, pH, buffers, co-solvents, etc.) under which a GLA polypeptide of the present application is capable of converting a substrate to the desired product compound, Exemplary “suitable reaction conditions” are provided in the present application and illustrated by the Examples. “Loading”, such as in “compound loading” or “enzyme loading” refers to the concentration or amount of a component in a reaction mixture at the start of the reaction. “Substrate” in the context of an enzymatic conversion reaction process refers to the compound or molecule acted on by the GLA polypeptide. “Product” in the context of an enzymatic conversion process refers to the compound or molecule resulting from the action of the GLA polypeptide on a substrate.
As used herein the term “culturing” refers to the growing of a population of microbial cells under any suitable conditions (e.g., using a liquid, gel or solid medium).
Recombinant polypeptides can be produced using any suitable methods known the art. Genes encoding the wild-type polypeptide of interest can be cloned in vectors, such as plasmids, and expressed in desired hosts, such as E. coli, S. cerevisiae, etc. Variants of recombinant polypeptides can be generated by various methods known in the art. Indeed, there is a wide variety of different mutagenesis techniques well known to those skilled in the art. In addition, mutagenesis kits are also available from many commercial molecular biology suppliers. Methods are available to make specific substitutions at defined amino acids (site-directed), specific or random mutations in a localized region of the gene (regio-specific), or random mutagenesis over the entire gene (e.g., saturation mutagenesis). Numerous suitable methods are known to those in the art to generate enzyme variants, including but not limited to site-directed mutagenesis of single-stranded DNA or double-stranded DNA using PCR, cassette mutagenesis, gene synthesis, error-prone PCR, shuffling, and chemical saturation mutagenesis, or any other suitable method known in the art. Non-limiting examples of methods used for DNA and protein engineering are provided in the following patents: U.S. Pat. Nos. 6,117,679; 6,420,175; 6,376,246; 6,586,182; 7,747,391; 7,747,393; 7,783,428; and 8,383,346. After the variants are produced, they can be screened for any desired property (e.g., high or increased activity, or low or reduced activity, increased thermal activity, increased thermal stability, and/or acidic pH stability, etc.). In some embodiments, “recombinant GLA polypeptides” (also referred to herein as “engineered GLA polypeptides,” “variant GLA enzymes,” and “GLA variants”) find use.
As used herein, a “vector” is a DNA construct for introducing a DNA sequence into a cell. In some embodiments, the vector is an expression vector that is operably linked to a suitable control sequence capable of effecting the expression in a suitable host of the polypeptide encoded in the DNA sequence. In some embodiments, an “expression vector” has a promoter sequence operably linked to the DNA sequence (e.g., transgene) to drive expression in a host cell, and in some embodiments, also comprises a transcription terminator sequence.
As used herein, the term “expression” includes any step involved in the production of the polypeptide including, but not limited to, transcription, post-transcriptional modification, translation, and post-translational modification. In some embodiments, the term also encompasses secretion of the polypeptide from a cell.
As used herein, the term “produces” refers to the production of proteins and/or other compounds by cells. It is intended that the term encompass any step involved in the production of polypeptides including, but not limited to, transcription, post-transcriptional modification, translation, and post-translational modification. In some embodiments, the term also encompasses secretion of the polypeptide from a cell.
As used herein, an amino acid or nucleotide sequence (e.g., a promoter sequence, signal peptide, terminator sequence, etc.) is “heterologous” to another sequence with which it is operably linked if the two sequences are not associated in nature.
As used herein, the terms “host cell” and “host strain” refer to suitable hosts for expression vectors comprising DNA provided herein (e.g., the polynucleotides encoding the GLA variants). In some embodiments, the host cells are prokaryotic or eukaryotic cells that have been transformed or transfected with vectors constructed using recombinant DNA techniques as known in the art.
The term “analogue” means a polypeptide having more than 70% sequence identity but less than 100% sequence identity (e.g., more than 75%, 78%, 80%, 83%, 85%, 88%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99% sequence identity) with a reference polypeptide. In some embodiments, analogues mean polypeptides that contain one or more non-naturally occurring amino acid residues including, but not limited, to homoarginine, ornithine and norvaline, as well as naturally occurring amino acids. In some embodiments, analogues also include one or more D-amino acid residues and non-peptide linkages between two or more amino acid residues.
The term “therapeutic” refers to a compound administered to a subject who shows signs or symptoms of pathology having beneficial or desirable medical effects.
The term “pharmaceutical composition” refers to a composition suitable for pharmaceutical use in a mammalian subject (e.g., human) comprising a pharmaceutically effective amount of an engineered GLA polypeptide encompassed by the invention and an acceptable carrier.
The term “effective amount” means an amount sufficient to produce the desired result. One of general skill in the art may determine what the effective amount by using routine experimentation.
The terms “isolated” and “purified” are used to refer to a molecule (e.g., an isolated nucleic acid, polypeptide, etc.) or other component that is removed from at least one other component with which it is naturally associated. The term “purified” does not require absolute purity, rather it is intended as a relative definition.
The term “subject” encompasses mammals such as humans, non-human primates, livestock, companion animals, and laboratory animals (e.g., rodents and lagamorphs). It is intended that the term encompass females as well as males.
As used herein, the term “patient” means any subject that is being assessed for, treated for, or is experiencing disease.
The term “infant” refers to a child in the period of the first month after birth to approximately one (1) year of age. As used herein, the term “newborn” refers to child in the period from birth to the 28th day of life. The term “premature infant” refers to an infant born after the twentieth completed week of gestation, yet before full term, generally weighing ˜500 to −2499 grams at birth. A “very low birth weight infant” is an infant weighing less than 1500 g at birth.
As used herein, the term “child” refers to a person who has not attained the legal age for consent to treatment or research procedures. In some embodiments, the term refers to a person between the time of birth and adolescence.
As used herein, the term “adult” refers to a person who has attained legal age for the relevant jurisdiction (e.g., 18 years of age in the United States). In some embodiments, the term refers to any fully grown, mature organism. In some embodiments, the term “young adult” refers to a person less than 18 years of age, but who has reached sexual maturity.
As used herein, “composition” and “formulation” encompass products comprising at least one engineered GLA of the present invention, intended for any suitable use (e.g., pharmaceutical compositions, dietary/nutritional supplements, feed, etc.).
The terms “administration” and “administering” a composition mean providing a composition of the present invention to a subject (e.g., to a person suffering from the effects of Fabry disease).
The term “carrier” when used in reference to a pharmaceutical composition means any of the standard pharmaceutical carrier, buffers, and excipients, such as stabilizers, preservatives, and adjuvants.
The term “pharmaceutically acceptable” means a material that can be administered to a subject without causing any undesirable biological effects or interacting in a deleterious manner with any of the components in which it is contained and that possesses the desired biological activity.
As used herein, the term “excipient” refers to any pharmaceutically acceptable additive, carrier, diluent, adjuvant, or other ingredient, other than the active pharmaceutical ingredient (API; e.g., the engineered GLA polypeptides of the present invention). Excipients are typically included for formulation and/or administration purposes.
The term “therapeutically effective amount” when used in reference to symptoms of disease/condition refers to the amount and/or concentration of a compound (e.g., engineered GLA polypeptides) that ameliorates, attenuates, or eliminates one or more symptom of a disease/condition or prevents or delays the onset of symptom(s).
The term “therapeutically effective amount” when used in reference to a disease/condition refers to the amount and/or concentration of a composition (e.g., engineered GLA polypeptides) that ameliorates, attenuates, or eliminates the disease/condition. In some embodiments, the term is use in reference to the amount of a composition that elicits the biological (e.g., medical) response by a tissue, system, or animal subject that is sought by the researcher, physician, veterinarian, or other clinician.
It is intended that the terms “treating,” “treat” and “treatment” encompass preventative (e.g., prophylactic), as well as palliative treatment.
Engineered GLA Expression and Activity:
Two strategies for secreted GLA expression were utilized, using the yeast MFα signal peptide (MF-SP) or a longer leader sequence of 83 amino acids (MF-leader) to drive secretion of a yeast codon-optimized mature human GLA. Clones were expressed from a pYT-72 vector in S. cerevisiae strain INVSc1. Both approaches provided supernatants with measurable activity on the fluorogenic substrate 4-methylumbelliferyl α-D-galactopyranoside (4-MuGal). However, the construct with the yeast MFα signal peptide provided 3-fold higher activities and was used as the starting sequence for directed evolution.
To identify mutational diversity, a 13-position conserved “homolog” combinatorial library and a 192-position site saturation mutagenesis library were constructed. Equivalent volumes of supernatant were screened in an unchallenged condition (no incubation, pH 4.8) or following a one-hour incubation in a low pH (3.9-4.2) or high pH (7.1-8.2) environment. GLA variants with increased activity due to increased GLA expression or GLA specific activity were identified based on their fold improvement over the parent GLA. GLA variants with increased stability were identified by dividing the fold-improvement observed under challenged conditions by the fold-improvement observed under unchallenged conditions. This approach reduces the bias towards selecting variants based on increased expression but without changes in specific activity at pH extremes. Composite activity scores (the product of fold-improvements for all three conditions) and stability (the product of stability scores) were used to rank mutations in improved variants for inclusion in subsequent GLA libraries.
Engineered GLA:
In some embodiments the engineered GLA which exhibits an improved property has at least about 85%, at least about 88%, at least about 90%, at least about 91%, at least about 92%, at least about 93%, at least about 94%, at least about 95%, at least about 96%, at least about 97%, at least about 98%, at least about 99%, or at about 100% amino acid sequence identity with SEQ ID NO:5, and an amino acid residue difference as compared to SEQ ID NO:5, at one or more amino acid positions (such as at 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 14, 15, 20 or more amino acid positions compared to SEQ ID NO:5, or a sequence having at least 85%, at least 88%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99% or greater amino acid sequence identity with SEQ ID NO:5). In some embodiment the residue difference as compared to SEQ ID NO:5, at one or more positions will include at least 1, 2, 3, 4, 5, 6, 7, 8, 9, 10 or more conservative amino acid substitutions. In some embodiments, the engineered GLA polypeptide is a polypeptide listed in Table 2.1, 2.2, 2.4, 2.5, or Table 7.1.
In some embodiments the engineered GLA which exhibits an improved property has at least about 85%, at least about 88%, at least about 90%, at least about 91%, at least about 92%, at least about 93%, at least about 94%, at least about 95%, at least about 96%, at least about 97%, at least about 98%, at least about 99%, or at about 100% amino acid sequence identity with SEQ ID NO:10, and an amino acid residue difference as compared to SEQ ID NO:10, at one or more amino acid positions (such as at 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 14, 15, 20 or more amino acid positions compared to SEQ ID NO:10, or a sequence having at least 85%, at least 88%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99% or greater amino acid sequence identity with SEQ ID NO:10). In some embodiment the residue difference as compared to SEQ ID NO:10, at one or more positions will include at least 1, 2, 3, 4, 5, 6, 7, 8, 9, 10 or more conservative amino acid substitutions. In some embodiments, the engineered GLA polypeptide is a polypeptide listed in Table 2.3.
In some embodiments the engineered GLA which exhibits an improved property has at least 85%, at least 88%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, or at least 99% amino acid sequence identity with SEQ ID NO:5. In some embodiments the engineered GLA which exhibits an improved property has at least 85%, at least 88%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, or at least 99% amino acid sequence identity with SEQ ID NO:10.
In some embodiments, the engineered GLA polypeptide is selected from SEQ ID NOS:15, 13, 10, and 18.
In some embodiments, the engineered GLA polypeptide comprises a functional fragment of an engineered GLA polypeptide encompassed by the invention. Functional fragments have at least 80%, 81%, 82%, 83%, 84%, 85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% of the activity of the engineered GLA polypeptide from which is was derived (i.e., the parent engineered GLA). A functional fragment comprises at least 80%, 81%, 82%, 83%, 84%, 85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98% and even 99% of the parent sequence of the engineered GLA. In some embodiments the functional fragment is truncated by less than 5, less than 10, less than 15, less than 10, less than 25, less than 30, less than 35, less than 40, less than 45, and less than 50 amino acids.
Polynucleotides Encoding Engineered Polypeptides, Expression Vectors and Host Cells:
The present invention provides polynucleotides encoding the engineered GLA polypeptides described herein. In some embodiments, the polynucleotides are operatively linked to one or more heterologous regulatory sequences that control gene expression to create a recombinant polynucleotide capable of expressing the polypeptide. Expression constructs containing a heterologous polynucleotide encoding the engineered GLA polypeptides can be introduced into appropriate host cells to express the corresponding GLA polypeptide.
As will be apparent to the skilled artisan, availability of a protein sequence and the knowledge of the codons corresponding to the various amino acids provide a description of all the polynucleotides capable of encoding the subject polypeptides. The degeneracy of the genetic code, where the same amino acids are encoded by alternative or synonymous codons, allows an extremely large number of nucleic acids to be made, all of which encode the engineered GLA polypeptide. Thus, having knowledge of a particular amino acid sequence, those skilled in the art could make any number of different nucleic acids by simply modifying the sequence of one or more codons in a way which does not change the amino acid sequence of the protein. In this regard, the present invention specifically contemplates each and every possible variation of polynucleotides that could be made encoding the polypeptides described herein by selecting combinations based on the possible codon choices, and all such variations are to be considered specifically disclosed for any polypeptide described herein, including the variants provided in Tables 2.1, 2.2, 2.3, 2.4, 2.5, and 6.1.
In various embodiments, the codons are preferably selected to fit the host cell in which the protein is being produced. For example, preferred codons used in bacteria are used for expression in bacteria. Consequently, codon optimized polynucleotides encoding the engineered GLA polypeptides contain preferred codons at about 40%, 50%, 60%, 70%, 80%, or greater than 90% of codon positions of the full length coding region.
In some embodiments, as described above, the polynucleotide encodes an engineered polypeptide having GLA activity with the properties disclosed herein, wherein the polypeptide comprises an amino acid sequence having at least 80%, 81%, 82%, 83%, 84%, 85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99% or more identity to a reference sequence selected from SEQ ID NOS:5, and/or 10, or the amino acid sequence of any variant as disclosed in Tables 2.1, 2.2, 2.3, 2.4, 2.5, or 6.1, and one or more residue differences as compared to the reference polypeptide of SEQ ID NOS:5, and/or 10, or the amino acid sequence of any variant as disclosed in Tables 2.1, 2.2, 2.3, 2.4, 2.5, or 6.1, (for example 1, 2, 3, 4, 5, 6, 7, 8, 9, 10 or more amino acid residue positions). In some embodiments, the reference sequence is selected from SEQ ID NO:5 and/or 10. In some embodiments, the polynucleotide encodes an engineered polypeptide having GLA activity with the properties disclosed herein, wherein the polypeptide comprises an amino acid sequence having at least 80%, 81%, 82%, 83%, 84%, 85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99% or more sequence identity to reference sequence SEQ ID NO:5, and one or more residue differences as compared to SEQ ID NO:5, at residue positions selected from those provided in Tables 2.1, 2.2, 2.4, 2.5, or 6.1, when optimally aligned with the polypeptide of SEQ ID NO:5.
In some embodiments, the polynucleotide encodes an engineered polypeptide having GLA activity with the properties disclosed herein, wherein the polypeptide comprises an amino acid sequence having at least 80%, 81%, 82%, 83%, 84%, 85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99% or more sequence identity to reference sequence SEQ ID NO:10, and one or more residue differences as compared to SEQ ID NO:10, at residue positions selected from those provided in Tables 2.3, when optimally aligned with the polypeptide of SEQ ID NO:10.
In some embodiments, the polynucleotide encoding the engineered GLA polypeptides comprises a polynucleotide sequence selected from a polynucleotide sequence encoding SEQ ID NOS:10, 13, 15, 18, 21, and 24. In some embodiments, the polynucleotide encoding an engineered GLA polypeptide has at least 80%, 81%, 82%, 83%, 84%, 85%, 86%, 87%, 88%, 89%, 90%, 93%, 95%, 96%, 97%, 98%, 99% nucleotide residue identity to SEQ ID NOS: 8, 9, 11, 12, 14, 16, 17, 19, 20, 22, and/or 23. In some embodiments, the polynucleotide encoding the engineered GLA polypeptides comprises a polynucleotide sequence selected from SEQ ID NOS:8, 9, 11, 12, 14, 16, 17, 19, 20, 22, and 23.
In some embodiments, the polynucleotides are capable of hybridizing under highly stringent conditions to a reference polynucleotide sequence selected from SEQ ID NOS: 8, 9, 11, 12, 14, 16, 17, 19, 20, 22, and 23, or a complement thereof, or a polynucleotide sequence encoding any of the variant GLA polypeptides provided herein. In some embodiments, the polynucleotide capable of hybridizing under highly stringent conditions encodes a GLA polypeptide comprising an amino acid sequence that has one or more residue differences as compared to SEQ ID NO:5 and/or 10, at residue positions selected from any positions as set forth in Tables 2.1, 2.2, 2.3, 2.4, 2.5, and/or 6.1.
In some embodiments, an isolated polynucleotide encoding any of the engineered GLA polypeptides provided herein is manipulated in a variety of ways to provide for expression of the polypeptide. In some embodiments, the polynucleotides encoding the polypeptides are provided as expression vectors where one or more control sequences is present to regulate the expression of the polynucleotides and/or polypeptides. Manipulation of the isolated polynucleotide prior to its insertion into a vector may be desirable or necessary depending on the expression vector. The techniques for modifying polynucleotides and nucleic acid sequences utilizing recombinant DNA methods are well known in the art.
In some embodiments, the control sequences include among other sequences, promoters, leader sequences, polyadenylation sequences, propeptide sequences, signal peptide sequences, and transcription terminators. As known in the art, suitable promoters can be selected based on the host cells used. Exemplary promoters for filamentous fungal host cells, include promoters obtained from the genes for Aspergillus oryzae TAKA amylase, Rhizomucor miehei aspartic proteinase, Aspergillus niger neutral alpha-amylase, Aspergillus niger acid stable alpha-amylase, Aspergillus niger or Aspergillus awamori glucoamylase (glaA), Rhizomucor miehei lipase, Aspergillus oryzae alkaline protease, Aspergillus oryzae triose phosphate isomerase, Aspergillus nidulans acetamidase, and Fusarium oxysporum trypsin-like protease (See e.g., WO 96/00787), as well as the NA2-tpi promoter (a hybrid of the promoters from the genes for Aspergillus niger neutral alpha-amylase and Aspergillus oryzae triose phosphate isomerase), and mutant, truncated, and hybrid promoters thereof. Exemplary yeast cell promoters can be from the genes can be from the genes for Saccharomyces cerevisiae enolase (ENO-1), Saccharomyces cerevisiae galactokinase (GAL1), Saccharomyces cerevisiae alcohol dehydrogenase/glyceraldehyde-3-phosphate dehydrogenase (ADH2/GAP), and Saccharomyces cerevisiae 3-phosphoglycerate kinase. Other useful promoters for yeast host cells are known in the art (See e.g., Romanos et al., Yeast 8:423-488 [1992]). Exemplary promoters for use in mammalian cells include, but are not limited to those from cytomegalovirus (CMV), Simian vacuolating virus 40 (SV40), from Homo sapiens phosphorglycerate kinase, beta actin, elongation factor-1a or glyceraldehyde-3-phosphate dehydrogenase, or from Gallus gallus' β-actin.
In some embodiments, the control sequence is a suitable transcription terminator sequence, a sequence recognized by a host cell to terminate transcription. The terminator sequence is operably linked to the 3′ terminus of the nucleic acid sequence encoding the polypeptide. Any terminator which is functional in the host cell of choice finds use in the present invention. For example, exemplary transcription terminators for filamentous fungal host cells can be obtained from the genes for Aspergillus oryzae TAKA amylase, Aspergillus niger glucoamylase, Aspergillus nidulans anthranilate synthase, Aspergillus niger alpha-glucosidase, and Fusarium oxysporum trypsin-like protease. Exemplary terminators for yeast host cells can be obtained from the genes for Saccharomyces cerevisiae enolase, Saccharomyces cerevisiae cytochrome C (CYC1), and Saccharomyces cerevisiae glyceraldehyde-3-phosphate dehydrogenase. Other useful terminators for yeast host cells are known in the art (See e.g., Romanos et al., supra). Exemplary terminators for mammalian cells include, but are not limited to those from cytomegalovirus (CMV), Simian vacuolating virus 40 (SV40), or from Homo sapiens growth hormone.
In some embodiments, the control sequence is a suitable leader sequence, a non-translated region of an mRNA that is important for translation by the host cell. The leader sequence is operably linked to the 5′ terminus of the nucleic acid sequence encoding the polypeptide. Any leader sequence that is functional in the host cell of choice may be used. Exemplary leaders for filamentous fungal host cells are obtained from the genes for Aspergillus oryzae TAKA amylase and Aspergillus nidulans triose phosphate isomerase. Suitable leaders for yeast host cells include, but are not limited to those obtained from the genes for Saccharomyces cerevisiae enolase (ENO-1), Saccharomyces cerevisiae 3-phosphoglycerate kinase, Saccharomyces cerevisiae alpha-factor, and Saccharomyces cerevisiae alcohol dehydrogenase/glyceraldehyde-3-phosphate dehydrogenase (ADH2/GAP).
The control sequence may also be a polyadenylation sequence, a sequence operably linked to the 3′ terminus of the nucleic acid sequence and which, when transcribed, is recognized by the host cell as a signal to add polyadenosine residues to transcribed mRNA. Any polyadenylation sequence which is functional in the host cell of choice may be used in the present invention. Exemplary polyadenylation sequences for filamentous fungal host cells include, but are not limited to those from the genes for Aspergillus oryzae TAKA amylase, Aspergillus niger glucoamylase, Aspergillus nidulans anthranilate synthase, Fusarium oxysporum trypsin-like protease, and Aspergillus niger alpha-glucosidase. Useful polyadenylation sequences for yeast host cells are also known in the art (See e.g., Guo and Sherman, Mol. Cell. Bio., 15:5983-5990 [1995]).
In some embodiments, the control sequence is a signal peptide coding region that codes for an amino acid sequence linked to the amino terminus of a polypeptide and directs the encoded polypeptide into the cell's secretory pathway. The 5′ end of the coding sequence of the nucleic acid sequence may inherently contain a signal peptide coding region naturally linked in translation reading frame with the segment of the coding region that encodes the secreted polypeptide. Alternatively, the 5′ end of the coding sequence may contain a signal peptide coding region that is foreign to the coding sequence. Any signal peptide coding region that directs the expressed polypeptide into the secretory pathway of a host cell of choice finds use for expression of the engineered GLA polypeptides provided herein. Effective signal peptide coding regions for filamentous fungal host cells include, but are not limited to the signal peptide coding regions obtained from the genes for Aspergillus oryzae TAKA amylase, Aspergillus niger neutral amylase, Aspergillus niger glucoamylase, Rhizomucor miehei aspartic proteinase, Humicola insolens cellulase, and Humicola lanuginosa lipase. Useful signal peptides for yeast host cells include, but are not limited to those from the genes for Saccharomyces cerevisiae alpha-factor and Saccharomyces cerevisiae invertase. Useful signal peptides for mammalian host cells include but are not limited to those from the genes for immunoglobulin gamma (IgG).
In some embodiments, the control sequence is a propeptide coding region that codes for an amino acid sequence positioned at the amino terminus of a polypeptide. The resultant polypeptide is referred to as a “proenzyme,” “propolypeptide,” or “zymogen,” in some cases). A propolypeptide can be converted to a mature active polypeptide by catalytic or autocatalytic cleavage of the propeptide from the propolypeptide.
In another aspect, the present invention also provides a recombinant expression vector comprising a polynucleotide encoding an engineered GLA polypeptide, and one or more expression regulating regions such as a promoter and a terminator, a replication origin, etc., depending on the type of hosts into which they are to be introduced. in some embodiments, the various nucleic acid and control sequences described above are joined together to produce a recombinant expression vector which includes one or more convenient restriction sites to allow for insertion or substitution of the nucleic acid sequence encoding the variant GLA polypeptide at such sites. Alternatively, the polynucleotide sequence(s) of the present invention are expressed by inserting the polynucleotide sequence or a nucleic acid construct comprising the polynucleotide sequence into an appropriate vector for expression. In creating the expression vector, the coding sequence is located in the vector so that the coding sequence is operably linked with the appropriate control sequences for expression.
The recombinant expression vector may be any vector (e.g., a plasmid or virus), that can be conveniently subjected to recombinant DNA procedures and can result in the expression of the variant GLA polynucleotide sequence. The choice of the vector will typically depend on the compatibility of the vector with the host cell into which the vector is to be introduced. The vectors may be linear or closed circular plasmids.
In some embodiments, the expression vector is an autonomously replicating vector (i.e., a vector that exists as an extra-chromosomal entity, the replication of which is independent of chromosomal replication, such as a plasmid, an extra-chromosomal element, a minichromosome, or an artificial chromosome). The vector may contain any means for assuring self-replication. In some alternative embodiments, the vector may be one which, when introduced into the host cell, is integrated into the genome and replicated together with the chromosome(s) into which it has been integrated. Furthermore, a single vector or plasmid or two or more vectors or plasmids which together contain the total DNA to be introduced into the genome of the host cell, or a transposon may be used.
In some embodiments, the expression vector preferably contains one or more selectable markers, which permit easy selection of transformed cells. A “selectable marker” is a gene the product of which provides for biocide or viral resistance, resistance to heavy metals, prototrophy to auxotrophs, and the like. Suitable markers for yeast host cells include, but are not limited to ADE2, HIS3, LEU2, LYS2, MET3, TRP1, and URA3. Selectable markers for use in a filamentous fungal host cell include, but are not limited to, amdS (acetamidase), argB (ornithine carbamoyltransferases), bar (phosphinothricin acetyltransferase), hph (hygromycin phosphotransferase), niaD (nitrate reductase), pyrG (orotidine-5′-phosphate decarboxylase), sC (sulfate adenyltransferase), and trpC (anthranilate synthase), as well as equivalents thereof. In another aspect, the present invention provides a host cell comprising a polynucleotide encoding at least one engineered GLA polypeptide of the present application, the polynucleotide being operatively linked to one or more control sequences for expression of the engineered GLA enzyme(s) in the host cell. Host cells for use in expressing the polypeptides encoded by the expression vectors of the present invention are well known in the art and include but are not limited to, fungal cells, such as yeast cells (e.g., Saccharomyces cerevisiae and Pichia pastoris [e.g., ATCC Accession No. 201178]); insect cells (e.g., Drosophila S2 and Spodoptera Sf9 cells), plant cells, animal cells (e.g., CHO, COS, and BHK), and human cells (e.g., HEK293T, human fibroblast, THP-1, Jurkat and Bowes melanoma cell lines).
Accordingly, in another aspect, the present invention provides methods for producing the engineered GLA polypeptides, where the methods comprise culturing a host cell capable of expressing a polynucleotide encoding the engineered GLA polypeptide under conditions suitable for expression of the polypeptide. In some embodiments, the methods further comprise the steps of isolating and/or purifying the GLA polypeptides, as described herein.
Appropriate culture media and growth conditions for the above-described host cells are well known in the art. Polynucleotides for expression of the GLA polypeptides may be introduced into cells by various methods known in the art. Techniques include, among others, electroporation, biolistic particle bombardment, liposome mediated transfection, calcium chloride transfection, and protoplast fusion.
The engineered GLA with the properties disclosed herein can be obtained by subjecting the polynucleotide encoding the naturally occurring or engineered GLA polypeptide to mutagenesis and/or directed evolution methods known in the art, and as described herein. An exemplary directed evolution technique is mutagenesis and/or DNA shuffling (See e.g., Stemmer, Proc. Natl. Acad. Sci. USA 91:10747-10751 [1994]; WO 95/22625; WO 97/0078; WO 97/35966; WO 98/27230; WO 00/42651; WO 01/75767 and U.S. Pat. No. 6,537,746). Other directed evolution procedures that can be used include, among others, staggered extension process (StEP), in vitro recombination (See e.g., Zhao et al., Nat. Biotechnol., 16:258-261 [1998]), mutagenic PCR (See e.g., Caldwell et al., PCR Methods Appl., 3:S136-S140 [1994]), and cassette mutagenesis (See e.g., Black et al., Proc. Natl. Acad. Sci. USA 93:3525-3529 [1996]).
For example, mutagenesis and directed evolution methods can be readily applied to polynucleotides to generate variant libraries that can be expressed, screened, and assayed. Mutagenesis and directed evolution methods are well known in the art (See e.g., U.S. Pat. Nos. 5,605,793, 5,811,238, 5,830,721, 5,834,252, 5,837,458, 5,928,905, 6,096,548, 6,117,679, 6,132,970, 6,165,793, 6,180,406, 6,251,674, 6,277,638, 6,287,861, 6,287,862, 6,291,242, 6,297,053, 6,303,344, 6,309,883, 6,319,713, 6,319,714, 6,323,030, 6,326,204, 6,335,160, 6,335,198, 6,344,356, 6,352,859, 6,355,484, 6,358,740, 6,358,742, 6,365,377, 6,365,408, 6,368,861, 6,372,497, 6,376,246, 6,379,964, 6,387,702, 6,391,552, 6,391,640, 6,395,547, 6,406,855, 6,406,910, 6,413,745, 6,413,774, 6,420,175, 6,423,542, 6,426,224, 6,436,675, 6,444,468, 6,455,253, 6,479,652, 6,482,647, 6,489,146, 6,506,602, 6,506,603, 6,519,065, 6,521,453, 6,528,311, 6,537,746, 6,573,098, 6,576,467, 6,579,678, 6,586,182, 6,602,986, 6,613,514, 6,653,072, 6,716,631, 6,946,296, 6,961,664, 6,995,017, 7,024,312, 7,058,515, 7,105,297, 7,148,054, 7,288,375, 7,421,347, 7,430,477, 7,534,564, 7,620,500, 7,620,502, 7,629,170, 7,702,464, 7,747,391, 7,747,393, 7,751,986, 7,776,598, 7,783,428, 7,795,030, 7,853,410, 7,868,138, 7,873,499, 7,904,249, 7,957,912, 8,383,346, 8,504,498, 8,849,575, 8,876,066, 8,768,871, and all related non-US counterparts; Ling et al., Anal. Biochem., 254(2):157-78 [1997]; Dale et al., Meth. Mol. Biol., 57:369-74 [1996]; Smith, Ann. Rev. Genet., 19:423-462 [1985]; Botstein et al., Science, 229:1193-1201 [1985]; Carter, Biochem. J., 237:1-7 [1986]; Kramer et al., Cell, 38:879-887 [1984]; Wells et al., Gene, 34:315-323 [1985]; Minshull et al., Curr. Op. Chem. Biol., 3:284-290 [1999]; Christians et al., Nat. Biotechnol., 17:259-264 [1999]; Crameri et al., Nature, 391:288-291 [1998]; Crameri, et al., Nat. Biotechnol., 15:436-438 [1997]; Zhang et al., Proc. Nat. Acad. Sci. U.S.A., 94:4504-4509 [1997]; Crameri et al., Nat. Biotechnol., 14:315-319 [1996]; Stemmer, Nature, 370:389-391 [1994]; Stemmer, Proc. Nat. Acad. Sci. USA, 91:10747-10751 [1994]; US Pat. Appln. Publn. Nos. 2008/0220990, US 2009/0312196, US2014/0005057, US2014/0214391, US2014/0221216; US2015/0050658, US2015/0133307, US2015/0134315 and all related non-US counterparts; WO 95/22625, WO 97/0078, WO 97/35966, WO 98/27230, WO 00/42651, WO 01/75767, and WO 2009/152336; all of which are incorporated herein by reference).
In some embodiments, the enzyme variants obtained following mutagenesis treatment are screened by subjecting the enzyme variants to a defined temperature (or other assay conditions) and measuring the amount of enzyme activity remaining after heat treatments or other assay conditions. DNA containing the polynucleotide encoding the GLA polypeptide is then isolated from the host cell, sequenced to identify the nucleotide sequence changes (if any), and used to express the enzyme in a different or the same host cell. Measuring enzyme activity from the expression libraries can be performed using any suitable method known in the art (e.g., standard biochemistry techniques, such as HPLC analysis).
For engineered polypeptides of known sequence, the polynucleotides encoding the enzyme can be prepared by standard solid-phase methods, according to known synthetic methods. In some embodiments, fragments of up to about 100 bases can be individually synthesized, then joined (e.g., by enzymatic or chemical litigation methods, or polymerase mediated methods) to form any desired continuous sequence. For example, polynucleotides and oligonucleotides disclosed herein can be prepared by chemical synthesis using the classical phosphoramidite method (See e.g., Beaucage et al., Tetra. Lett., 22:1859-69 [1981]; and Matthes et al., EMBO J., 3:801-05 [1984]), as it is typically practiced in automated synthetic methods. According to the phosphoramidite method, oligonucleotides are synthesized (e.g., in an automatic DNA synthesizer), purified, annealed, ligated and cloned in appropriate vectors.
Accordingly, in some embodiments, a method for preparing the engineered GLA polypeptide can comprise: (a) synthesizing a polynucleotide encoding a polypeptide comprising an amino acid sequence selected from the amino acid sequence of any variant provided in Table 2.1, 2.2, 2.3, 2.4, 2.5, and/or 6.1, as well as SEQ ID NOS:10, 13, 15, 18, 21, and/or 24, and (b) expressing the GLA polypeptide encoded by the polynucleotide. In some embodiments of the method, the amino acid sequence encoded by the polynucleotide can optionally have one or several (e.g., up to 3, 4, 5, or up to 10) amino acid residue deletions, insertions and/or substitutions. In some embodiments, the amino acid sequence has optionally 1-2, 1-3, 1-4, 1-5, 1-6, 1-7, 1-8, 1-9, 1-10, 1-15, 1-20, 1-21, 1-22, 1-23, 1-24, 1-25, 1-30, 1-35, 1-40, 1-45, or 1-50 amino acid residue deletions, insertions and/or substitutions. In some embodiments, the amino acid sequence has optionally 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 30, 30, 35, 40, 45, or 50 amino acid residue deletions, insertions and/or substitutions. In some embodiments, the amino acid sequence has optionally 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 18, 20, 21, 22, 23, 24, or 25 amino acid residue deletions, insertions and/or substitutions. In some embodiments, the substitutions can be conservative or non-conservative substitutions.
The expressed engineered GLA polypeptide can be assessed for any desired improved property (e.g., activity, selectivity, stability, acid tolerance, protease sensitivity, etc.), using any suitable assay known in the art, including but not limited to the assays and conditions described herein.
In some embodiments, any of the engineered GLA polypeptides expressed in a host cell are recovered from the cells and/or the culture medium using any one or more of the well-known techniques for protein purification, including, among others, lysozyme treatment, sonication, filtration, salting-out, ultra-centrifugation, and chromatography.
Chromatographic techniques for isolation of the GLA polypeptides include, among others, reverse phase chromatography high performance liquid chromatography, ion exchange chromatography, hydrophobic interaction chromatography, gel electrophoresis, and affinity chromatography. Conditions for purifying a particular enzyme depends, in part, on factors such as net charge, hydrophobicity, hydrophilicity, molecular weight, molecular shape, etc., and will be apparent to those having skill in the art. In some embodiments, affinity techniques may be used to isolate the improved variant GLA enzymes. In some embodiments utilizing affinity chromatography purification, any antibody which specifically binds the variant GLA polypeptide finds use. In some embodiments utilizing affinity chromatography purification, proteins that bind to the glycans covalently attached to GLA find use. In still other embodiments utilizing affinity-chromatography purifications, any small molecule that binds to the GLA active site finds use. For the production of antibodies, various host animals, including but not limited to rabbits, mice, rats, etc., are immunized by injection with a GLA polypeptide (e.g., a GLA variant), or a fragment thereof. in some embodiments, the GLA polypeptide or fragment is attached to a suitable carrier, such as BSA, by means of a side chain functional group or linkers attached to a side chain functional group.
In some embodiments, the engineered GLA polypeptide is produced in a host cell by a method comprising culturing a host cell (e.g., S. cerevisiae, Daucus carota, Nicotiana tabacum, H. sapiens (e.g., HEK293T), or Cricetulus griseus (e.g., CHO)) comprising a polynucleotide sequence encoding an engineered GLA polypeptide as described herein under conditions conducive to the production of the engineered GLA polypeptide and recovering the engineered GLA polypeptide from the cells and/or culture medium.
In some embodiments, the invention encompasses a method of producing an engineered GLA polypeptide comprising culturing a recombinant eukaryotic cell comprising a polynucleotide sequence encoding an engineered GLA polypeptide having at least 80%, 81%, 82%, 83%, 84%, 85%, 86%, 87%, 88%, 89%, 90%, 95%, 96%, 97%, 98%, 99%, or 100% sequence identity to reference sequences SEQ ID NOS:5 and/or 10, and one or more amino acid residue differences as compared to SEQ ID NO:5 and/or 10, selected from those provided in Tables 2.1, 2.2, 2.4, 2.5, and/or 6.1, and/or combinations thereof when optimally aligned with the amino acid sequence of SEQ ID NO:5 and/or 10, under suitable culture conditions to allow the production of the engineered GLA polypeptide and optionally recovering the engineered GLA polypeptide from the culture and/or cultured bacterial cells.
In some embodiments, once the engineered GLA polypeptides are recovered from the recombinant host cells or cell culture medium, they are further purified by any suitable method(s) known in the art. In some additional embodiments, the purified GLA polypeptides are combined with other ingredients and compounds to provide compositions and formulations comprising the engineered GLA polypeptide as appropriate for different applications and uses (e.g., pharmaceutical compositions). In some additional embodiments, the purified GLA polypeptides, or the formulated GLA polypeptides are lyophilized
Compositions:
The present invention provides various compositions and formats, including but not limited to those described below. In some embodiments, the present invention provides engineered GLA polypeptides suitable for use in pharmaceutical and other compositions, such as dietary/nutritional supplements.
Depending on the mode of administration, these compositions comprising a therapeutically effective amount of an engineered GLA according to the invention are in the form of a solid, semi-solid, or liquid. In some embodiments, the compositions include other pharmaceutically acceptable components such as diluents, buffers, excipients, salts, emulsifiers, preservatives, stabilizers, fillers, and other ingredients. Details on techniques for formulation and administration are well known in the art and described in the literature.
In some embodiments, the engineered GLA polypeptides are formulated for use in pharmaceutical compositions. Any suitable format for use in delivering the engineered GLA polypeptides find use in the present invention, including but not limited to pills, tablets, gel tabs, capsules, lozenges, dragees, powders, soft gels, sol-gels, gels, emulsions, implants, patches, sprays, ointments, liniments, creams, pastes, jellies, paints, aerosols, chewing gums, demulcents, sticks, solutions, suspensions (including but not limited to oil-based suspensions, oil-in water emulsions, etc.), slurries, syrups, controlled release formulations, suppositories, etc. In some embodiments, the engineered GLA polypeptides are provided in a format suitable for injection or infusion (i.e., in an injectable formulation). In some embodiments, the engineered GLA polypeptides are provided in biocompatible matrices such as sol-gels, including silica-based (e.g., oxysilane) sol-gels. In some embodiments, the engineered GLA polypeptides are encapsulated. In some alternative embodiments, the engineered GLA polypeptides are encapsulated in nanostructures (e.g., nanotubes, nanotubules, nanocapsules, or microcapsules, microspheres, liposomes, etc.). Indeed, it is not intended that the present invention be limited to any particular delivery formulation and/or means of delivery. It is intended that the engineered GLA polypeptides be administered by any suitable means known in the art, including but not limited to parenteral, oral, topical, transdermal, intranasal, intraocular, intrathecal, via implants, etc.
In some embodiments, the engineered GLA polypeptides are chemically modified by glycosylation, chemical crosslinking reagents, pegylation (i.e., modified with polyethylene glycol [PEG] or activated PEG, etc.) or other compounds (See e.g., Ikeda, Amino Acids 29:283-287 [2005]; U.S. Pat. Nos. 7,531,341, 7,534,595, 7,560,263, and 7,53,653; US Pat. Appln. Publ. Nos. 2013/0039898, 2012/0177722, etc.). Indeed, it is not intended that the present invention be limited to any particular delivery method and/or mechanism.
In some additional embodiments, the engineered GLA polypeptides are provided in formulations comprising matrix-stabilized enzyme crystals. In some embodiments, the formulation comprises a cross-linked crystalline engineered GLA enzyme and a polymer with a reactive moiety that adheres to the enzyme crystals. The present invention also provides engineered GLA polypeptides in polymers.
In some embodiments, compositions comprising the engineered GLA polypeptides of the present invention include one or more commonly used carrier compounds, including but not limited to sugars (e.g., lactose, sucrose, mannitol, and/or sorbitol), starches (e.g., corn, wheat, rice, potato, or other plant starch), cellulose (e.g., methyl cellulose, hydroxypropylmethyl cellulose, sodium carboxy-methylcellulose), gums (e.g., arabic, tragacanth, guar, etc.), and/or proteins (e.g., gelatin, collagen, etc.).
In some embodiments, the present invention provides engineered GLA polypeptides suitable for use in decreasing the concentration of glycolipids in fluids such as blood, cerebrospinal fluid, etc. The dosage of engineered GLA polypeptide(s) administered depends upon the condition or disease, the general condition of the subject, and other factors known to those in the art. In some embodiments, the compositions are intended for single or multiple administrations. In some embodiments, it is contemplated that the concentration of engineered GLA polypeptide(s) in the composition(s) administered to a human with Fabry disease is sufficient to effectively treat, and/or ameliorate disease (e.g., Fabry disease). In some embodiments, the engineered GLA polypeptides are administered in combination with other pharmaceutical and/or dietary compositions.
The following Examples, including experiments and results achieved, are provided for illustrative purposes only and are not to be construed as limiting the present invention.
In the experimental disclosure below, the following abbreviations apply: ppm (parts per million); M (molar); mM (millimolar), uM and μM (micromolar); nM (nanomolar); mol (moles); gm and g (gram); mg (milligrams); ug and μg (micrograms); L and l (liter); ml and mL (milliliter); cm (centimeters); mm (millimeters); um and μm (micrometers); sec. (seconds); min(s) (minute(s)); h(s) and hr(s) (hour(s)); U (units); MW (molecular weight); rpm (rotations per minute); ° C. (degrees Centigrade); CDS (coding sequence); DNA (deoxyribonucleic acid); RNA (ribonucleic acid); E. coli W3110 (commonly used laboratory E. coli strain, available from the Coli Genetic Stock Center [CGSC], New Haven, Conn.); HPLC (high pressure liquid chromatography); MWCO (molecular weight cut-off); SDS-PAGE (sodium dodecyl sulfate polyacrylamide gel electrophoresis); PES (polyethersulfone); CFSE (carboxyfluorescein succinimidyl ester); IPTG (isopropyl β-D-1-thiogalactopyranoside); PMBS (polymyxin B sulfate); NADPH (nicotinamide adenine dinucleotide phosphate); GIDH (glutamate dehydrogenase); FIOPC (fold improvements over positive control); PBMC (peripheral blood mononuclear cells); LB (Luria broth); MeOH (methanol); Athens Research (Athens Research Technology, Athens, Ga.); ProSpec (ProSpec Tany Technogene, East Brunswick, N.J.); Sigma-Aldrich (Sigma-Aldrich, St. Louis, Mo.); Ram Scientific (Ram Scientific, Inc., Yonkers, N.Y.); Pall Corp. (Pall, Corp., Pt. Washington, N.Y.); Millipore (Millipore, Corp., Billerica Mass.); Difco (Difco Laboratories, BD Diagnostic Systems, Detroit, Mich.); Molecular Devices (Molecular Devices, LLC, Sunnyvale, Calif.); Kuhner (Adolf Kuhner, AG, Basel, Switzerland); Axygen (Axygen, Inc., Union City, Calif.); Toronto Research Chemicals (Toronto Research Chemicals Inc., Toronto, Ontario, Canada); Cambridge Isotope Laboratories, (Cambridge Isotope Laboratories, Inc., Tewksbury, Mass.); Applied Biosystems (Applied Biosystems, part of Life Technologies, Corp., Grand Island, N.Y.), Agilent (Agilent Technologies, Inc., Santa Clara, Calif.); Thermo Scientific (part of Thermo Fisher Scientific, Waltham, Mass.); Corning (Corning, Inc., Palo Alto, Calif.); Megazyme (Megazyme International, Wicklow, Ireland); Enzo (Enzo Life Sciences, Inc., Farmingdale, N.Y.); GE Healthcare (GE Healthcare Bio-Sciences, Piscataway, N.J.); Pierce (Pierce Biotechnology (now part of Thermo Fisher Scientific), Rockford, Ill.); LI-COR (LI-COR Biotechnology, Lincoln, Nebr.); Amicus (Amicus Therapeutics, Cranbury, N.J.); Phenomenex (Phenomenex, Inc., Torrance, Calif.); Optimal (Optimal Biotech Group, Belmont, Calif.); and Bio-Rad (Bio-Rad Laboratories, Hercules, Calif.).
The following polynucleotide and polypeptide sequences find use in the present invention. In some cases (as shown below), the polynucleotide sequence is followed by the encoded polypeptide.
A synthetic gene coding for a WT human GLA was designed for optimized gene expression in Saccharomyces cerevisiae (SEQ ID NO:3), assembled, and subcloned into the E. coli expression vector pCK100900i (SEQ ID NO:6).
A chimeric GLA expression construct encoding a 19 amino acid S. cerevisae MFalpha signal peptide fused to the mature form of yeast-optimized GLA was generated in a yeast expression vector designed for secreted expression, as follows. A fragment coding for the MFalpha signal peptide (SEQ ID NO:25) was amplified by PCR using the oligonucleotides MM0435 (SEQ ID NO:27) and MM0439 (SEQ ID NO:28) from S288C genomic DNA, and a fragment coding for a synthetic GLA (SEQ ID NO:3) was amplified using primers MM0514 (SEQ ID NO:29) and MM0481 (SEQ ID NO:30). Additional sequence at the 5′ ends of these oligonucleotides provide homology for yeast recombination cloning when cotransformed with linearized plasmid pYT-72Bgl (SEQ ID NO:7). In the resulting vector, the expression of fusion protein SP-GLA (SEQ ID NO:36) is driven by the ADH2 promoter. A fusion construct encoding a fusion of an 83 amino acid MFalpha leader peptide (SEQ ID NO:38) N-terminally fused to GLA (SEQ ID NO:37) was cloned using the same techniques. Recombination cloning and gene expression were performed in S. cerevisiae strain INVSc1. Directed evolution techniques generally known by those skilled in the art were used to generate libraries of gene variants from this plasmid construct (See e.g., U.S. Pat. No. 8,383,346 and WO2010/144103).
A chimeric GLA expression construct encoding a synthetic signal peptide fused to a synthetic gene coding for the mature human GLA coding sequence for secreted expression in transient transfections was generated as follows. Oligonucleotides PLEV113Fw (SEQ ID NO:32) and SPGLARv (SEQ ID NO:33) were used to amplify a fragment coding for a synthetic signal peptide (SEQ ID NO:31) using PCR. A second fragment coding for the native human coding sequence for the mature form of GLA (SEQ ID NO:4) was amplified using oligonucleotides SPGLAFw (SEQ ID NO:34) and GLARv (SEQ ID NO:35). Splicing by Overlap Extension PCR was used to recombine these fragments, and the resulting chimeric fragment was ligated into the HindIII/Not I linearized mammalian expression vector pLEV113. Directed evolution techniques generally known by those skilled in the art were used to generate specific gene variants from this plasmid construct.
High-Throughput (HTP) Growth of GLA and GLA Variants
Yeast (INVSc1) cells transformed with vectors expressing GLA and GLA variants using the lithium acetate method were selected on SD-Ura agar plates. After 72 h incubation at 30° C. colonies were placed into the wells of Axygen® 1.1 ml 96-well deep well plates filled with 200 μl/well SD-Ura broth (2 g/L SD-Ura, 6.8 g/L yeast nitrogen base without amino acids [Sigma Aldrich]), 3.06 g/L sodium dihydrogen phosphate, 0.804 g/L disodium hydrogen phosphate, pH 6.0 supplemented with 6% glucose. The cells were allowed to grow for 20-24 hours in a Kuhner shaker (250 rpm, 30° C., and 85% relative humidity). Overnight culture samples (20 μL) were transferred into Corning Costar® 96-well deep plates filled with 3804 of SD-ura broth supplemented with 2% glucose. The plates were incubated for 66-84 h in a Kuhner shaker (250 rpm, 30° C., and 85% relative humidity). The cells were then pelleted (4000 rpm×20 min), and the supernatants isolated and stored at 4° C. prior to analysis.
HTP-Analysis of Supernatants
GLA variant activity was determined by measuring the hydrolysis of 4-methylumbelliferyl α-D-galactopyranoside (MUGal). For this assay, 5-50 μL of yeast culture supernatant produced as described above, was mixed with 0-45 μL of Mcllvaine Buffer (Mcllvaine, J. Biol. Chem., 49:183-186 [1921]), pH 4.8 and 50 μL of 2 mM MUGal in 50 mM citrate, 200 mM KCl, pH 4.6 in a 96-well, black, opaque bottom plate. The reactions were mixed briefly and incubated at 37° C. for 30-180 minutes, prior to quenching with 100 μL of 1 M sodium carbonate. Hydrolysis was analyzed using a SpectraMax® M2 microplate reader monitoring fluorescence (Ex. 355 nm, Em. 448 nm).
HTP-Analysis of Supernatants Pretreated with Acid
GLA variants were challenged with acidic buffer to simulate the extreme pHs that the variants may encounter in lysosomes. First, 50 μL of yeast culture supernatant and 50 uL of McIlvaine buffer (pH 3.3-4.3) were added to the wells of a 96-well round bottom plate. The plates were sealed with a PlateLoc Thermal Microplate Sealer (Agilent) and incubated at 37° C. for 1-3 h. For the assay, 10-50 μL of acid-pH-challenged sample was mixed with 0-40 μL of McIlvaine buffer pH 4.8, 25 μL of 1 M citrate buffer pH 4.3 and 25 μL of 4 mM MUGal in McIlvaine buffer pH 4.8. The reactions were mixed briefly and incubated at 37° C. for 30-180 minutes, prior to quenching with 100 μL of 1 M sodium carbonate. Hydrolysis was analyzed using a SpectraMax® M2 microplate reader monitoring fluorescence (Ex. 355 nm, Em. 448 nm).
HTP-Analysis of Supernatants Pretreated with Base
GLA variants were challenged with basic (neutral) buffer to simulate the pHs that the variants encounter in the blood following their administration to a patient. First, 50 μL of yeast culture supernatant and 50 uL of McIlvaine buffer (pH 7.0-8.2) or 200 mM sodium bicarbonate (pH 9.1-9.7) were added to the wells of a 96-well round bottom plate. The plates were sealed and incubated at 37° C. for 1-18 h. For the assay, 10-50 μL of basic-pH-challenged sample was mixed with 0-40 μL of McIlvaine buffer pH 4.8, 25 μL of 1 M citrate buffer pH 4.3 and 25 μL of 4 mM MUGal in McIlvaine buffer pH 4.8. The reactions were mixed briefly and incubated at 37° C. for 30-180 minutes, prior to quenching with 100 μL of 1 M sodium carbonate. Hydrolysis was analyzed using a SpectraMax® M2 microplate reader monitoring fluorescence (Ex. 355 nm, Em. 448 nm).
HTP-Analysis of Supernatants Pretreated with Bovine Serum
GLA variants were challenged with bovine serum to simulate the conditions the variants encounter following infusion into a patient. First, 20 μL of yeast culture supernatant and 80 μL of bovine serum were added to the wells of a 96-well round bottom plate. The plates were sealed and incubated at 37° C. for 1 h. For the assay, 50 μL of serum-challenged sample was mixed with 25 μL of 1 M citrate buffer pH 4.3 and 25 μL of 4 mM MUGal in McIlvaine buffer pH 4.8. The reactions were mixed briefly and incubated at 37° C. for 180 minutes, prior to quenching with 100 μL of 1 M sodium carbonate. Hydrolysis was analyzed using a SpectraMax® M2 microplate reader monitoring fluorescence (Ex. 355 nm, Em. 448 nm).
1Relative activity was calculated as activity of the variant/activity of WT GLA (SEQ ID NO: 5 (encoded by SEQ ID NO: 3).
2+ = 0.5 to 1.5 relative activity over WT GLA (SEQ ID NO: 5); ++ = >1.5 to 2.5 relative activity over WT GLA (SEQ ID NO: 5); and +++ = >2.5 relative activity over WT GLA (SEQ ID NO: 5).
1Relative activity was calculated as activity of the variant/activity of WT GLA (SEQ ID NO: 5 (encoded by SEQ ID NO: 3).
2Variant # 73 (Rd2BB) has the polynucleotide sequence of SEQ ID NO: 8 and polypeptide sequence of SEQ ID NO: 10.
3− = <0.5 relative activity to WT GLA (SEQ ID NO: 5); + = 0.5 to 1.5 relative activity over WT GLA (SEQ ID NO: 5); ++ = >1.5 to 2.5 relative activity over WT GLA (SEQ ID NO: 5); and +++ = >2.5 relative activity over WT GLA (SEQ ID NO: 5).
1Relative activity was calculated as activity of the variant/activity of Rd2BB (SEQ ID NO: 10 (encoded by SEQ ID NO: 8).
2− = <0.5 relative activity to Rd2BB (SEQ ID NO: 10); + = 0.5 to 1.5 relative activity over Rd2BB (SEQ ID NO: 10); ++ = >1.5 to 2.5 relative activity over Rd2BB (SEQ ID NO: 10); and +++ = >2.5 relative activity over Rd2BB (SEQ ID NO: 10).
1 Relative activity was calculated as activity of the variant/activity of Rd3BB (SEQ ID NO: 13 (encoded by SEQ ID NO: 11).
2 Variant #326 (Rd4BB) has the polynucleotide sequence of SEQ ID NO: 14 and polypeptide sequence of SEQ ID NO: 15.
3 − = <0.5 relative activity to Rd3BB (SEQ ID NO: 13); + = 0.5 to 1.5 relative activity over Rd3BB (SEQ ID NO: 13); ++ = >1.5 to 2.5 relative activity over Rd3BB (SEQ ID NO: 13); and +++ = >2.5 relative activity over Rd3BB (SEQ ID NO: 13).
1Relative activity was calculated as activity of the variant/activity of Rd4BB (SEQ ID NO: 15 (encoded by SEQ ID NO: 14).
2Variant # 395 (Rd5BB) has the polynucleotide sequence of SEQ ID NO: 39 and polypeptide sequence of SEQ ID NO: 40.
3Variant # 402 (Rd6BB) has the polynucleotide sequence of SEQ ID NO: 41 and polypeptide sequence of SEQ ID NO: 42
4− = <0.5 relative activity to Rd4BB (SEQ ID NO: 15); + = 0.5 to 1.5 relative activity over Rd4BB (SEQ ID NO: 15); ++ = >1.5 to 2.5 relative activity over Rd4BB (SEQ ID NO: 15); and +++ = >2.5 relative activity over Rd4BB (SEQ ID NO: 15).
Production of GLA in Yeast
In order to produce GLA-containing supernatant, replica HTP-cultures of GLA were grown as described in Example 2. Supernatants from replica cultures (n=12-36) were combined prior to further analysis.
Production of GLA in HEK293T Cells
Secreted expression of GLA variants in mammalian cells was performed by transient transfection of HEK293 cells. Cells were transfected with GLA variants (SEQ ID NOS:3, 4, 9, 12, 17, 20, 23, and 41) fused to an N-terminal synthetic mammalian signal peptide and subcloned into the mammalian expression vector pLEV113 as described in Example 1. HEK293 cells were transfected with plasmid DNA and grown in suspension for 4 days using techniques known to those skilled in the art. Supernatants were collected and stored at 4° C.
Purification of GLA Variants from Mammalian Cell Supernatants
GLA variants were purified from mammalian culture supernatant essentially as known in the art (See, Yasuda et al., Prot. Exp. Pur., 37, 499-506 [2004]). Concanavalin A resin (Sigma Aldrich) was equilibrated with 0.1 M sodium acetate, 0.1 M NaCl, 1 mM MgCl2, CaCl2, and MnCl2 pH 6.0 (Con A binding buffer). Supernatant was diluted 1:1 with binding buffer and loaded onto the column. The column was washed with 15 volumes of Concanavalin A binding buffer, and samples were eluted by the addition of Concanavalin A binding buffer including 0.9 M methyl-α-D-mannopyranoside and 0.9 M methyl-α-D-glucopyranoside. Eluted protein was concentrated and buffer exchanged three times using a Centricon® Plus-20 filtration unit with a 10 kDa molecular weight cut off (Millipore) into ThioGal binding buffer (25 mM citrate-phosphate, 0.1 M NaCl, pH 4.8). Buffer exchanged samples were loaded onto a Immobilized-D-galactose resin (Pierce) equilibrated with ThioGal binding buffer. The resin was washed with six volumes of ThioGal binding buffer and eluted with 25 mM citrate phosphate, 0.1 M NaCl, 0.1 M D-galactose, pH 5.5. Eluted samples were concentrated using a Centricon® Plus-20 filtration unit with a 10 kDa molecular weight cut off. Purification resulted in between 2.4-10 μg of purified protein/ml of culture supernatant based on Bradford quantitation.
SDS-PAGE Analysis of GLA Variants
Samples of yeast culture supernatant and mammalian cell culture supernatant and purified GLA were analyzed by SDS-PAGE. In the yeast supernatants, GLA levels were too low to be detected via this method. Bands corresponding to the ˜49 kDa predicted GLA molecular weight were found in both mammalian cell culture supernatants and purified GLA samples.
Immunoblot Analysis of GLA Variants
Samples of yeast supernatant and mammalian cell culture supernatant were analyzed by immunoblot. Briefly, samples were separated via SDS-PAGE. Protein was transferred to a PVDF membrane using an iBlot dry blot system (Life Technologies). The membrane was blocked with Odyssey blocking buffer (TBS) (LI-COR) for 1 h at RT and probed with a 1:250 dilution of rabbit α-GLA IgG (Thermo-Fischer) in Odyssey blocking buffer with 0.2% Tween® 20 for 14 h at 4° C. The membrane was washed 4×5 mM with Tris-buffered saline+0.1% Tween® 20 and probed with a 1:5000 dilution of IRDye800CW donkey α-rabbit IgG (LI-COR) in Odyssey blocking buffer with 0.2% Tween® 20 and 0.01% SDS for 1 hr at RT. The membrane was washed 4×5 min with Tris-buffered saline+0.1% Tween® 20, and analyzed using an Odyssey Imager (LI-COR). Bands corresponding to the ˜49 kDa predicted GLA molecular weight were found in both the mammalian cell culture and yeast supernatants. In S. cerevisiae expressed samples, mutants containing the mutation E367N ran at a slightly higher MW. This mutation introduces a canonical NXT N-linked glycosylation site (where X is any amino acid except P) and the possible introduction of an additional N-linked glycan may account for the higher MW.
Optimization of Signal Peptide for Secreted Expression of GLA by S. cerevisiae
S. cerevisiae transformed with Mfleader-GLA (SEQ ID NO:7), SP-GLA (SEQ ID NO:36) or a vector control were grown in HTP as described in Example 2. Cultures were grown for 48-120 h prior to harvest of the supernatant and analysis (n=6) as described in Example 2.
pH Stability of GLA Variants Expressed in S. cerevisiae
GLA variants were challenged with different buffers to assess the overall stability of the enzyme. First, 50 μL of supernatant from a GLA variant yeast culture and 50 uL of Mcllvaine buffer (pH 2.86-9.27) or 200 mM sodium carbonate (pH 9.69) were added to the wells of a 96-well round bottom plate (Costar #3798, Corning). The plates were sealed and incubated at 37° C. for 1 h. For the assay, 50 μL of challenged supernatant was mixed with 25 μL of 1 M citrate buffer pH 4.3 and 25 μL of 4 mM MUGal in Mcllvaine buffer pH 4.8. The reactions were mixed briefly and incubated at 37° C. for 60-180 minutes, prior to quenching with 100 μL of 1 M sodium carbonate. Hydrolysis was analyzed using a SpectraMax® M2 microplate reader monitoring fluorescence (Ex. 355 nm, Em. 448 nm).
Thermostability of GLA Variants Expressed in S. cerevisiae
GLA variants were challenged at various temperatures in the presence and absence of 1 μM 1-deoxygalactonojirimycin (Migalastat; Toronto Research Chemicals) to assess the overall stability of the enzyme. First, 50 μL of supernatant from a GLA variant yeast culture and 50 uL of Mcllvaine buffer (pH 7.65)+/−2 mM 1-deoxygalactonojirimycin were added to the wells of a 96-well PCR plate (Biorad, HSP-9601). The plates were sealed and incubated at 30-54° C. for 1 h using the gradient program of a thermocycler. For the assay, 50 μL of challenged supernatant was mixed with 25 μL of 1 M citrate buffer pH 4.3 and 25 μL of 4 mM MUGal in McIlvaine buffer pH 4.8. The reactions were mixed briefly and incubated at 37° C. for 90 minutes, prior to quenching with 100 μL of 1 M sodium carbonate. Hydrolysis was analyzed using a SpectraMax® M2 microplate reader monitoring fluorescence (Ex. 355 nm, Em. 448 nm).
Serum Stability of GLA Variants Expressed in S. cerevisiae
To assess the relative stability of variants in the presence of blood, samples were exposed to serum. First, 20 μL of supernatant from a GLA variant yeast culture and 0-80 μL of water and 0-80 μL of bovine serum were added to the wells of a 96-well round bottom plate (Costar #3798, Corning). The plates were sealed and incubated at 37° C. for 1 h. For the assay, 50 μL of challenged supernatant was mixed with 25 μL of 1 M citrate buffer pH 4.3 and 25 μL of 4 mM MUGal in McIlvaine buffer pH 4.8. The reactions were mixed briefly and incubated at 37° C. for 90 minutes, prior to quenching with 100 μL of 1 M sodium carbonate. Hydrolysis was analyzed using a SpectraMax® M2 microplate reader monitoring fluorescence (Ex. 355 nm, Em. 448 nm).
Relative Activities of GLA Variants Expressed in HEK293T Cells
Supernatants from GLA variants expressed in HEKT293T cells were serially diluted 2× with supernatant from an non GLA expressing yeast culture. Dilutions (50 μL) were mixed with 25 μL of 4 mM MUGal in McIlvaine Buffer pH 4.8 and 25 μL of 1 M citrate buffer pH 4.3 in a Corning® 96-well, black, opaque bottom plate. The reactions were mixed briefly and incubated at 37° C. for 60 minutes, prior to quenching with 100 μL of 1 M sodium carbonate. Hydrolysis was analyzed using a SpectraMax® M2 microplate reader monitoring fluorescence (Ex. 355 nm, Em. 448 nm).
pH Stability of GLA Variants Expressed in HEK293T Cells
GLA variants were challenged with different buffers to assess their overall stability. Supernatants from mammalian cell cultures were normalized to equal activities by dilution with supernatant from a non GLA expressing culture. Normalized supernatants (50 μL) and 50 uL of McIlvaine buffer (pH 4.06-8.14) were added to the wells of a 96-well round bottom plate (Costar #3798, Corning). The plates were sealed and incubated at 37° C. for 3 h. For the assay, 50 μL of challenged supernatant was mixed with 25 μL of 1 M citrate buffer pH 4.3 and 25 μL of 4 mM MUGal in Mcllvaine buffer pH 4.8. The reactions were mixed briefly and incubated at 37° C. for 3 h, prior to quenching with 100 μL of 1 M sodium carbonate. Hydrolysis was analyzed using a SpectraMax® M2 microplate reader monitoring fluorescence (Ex. 355 nm, Em. 448 nm).
All enzymes were found to be more stable versus pH challenges when compared to WT GLA expressed in S. cerevisiae (compare with
Thermostability of GLA Variants Expressed in HEK293T cells
GLA variants were challenged at various temperatures in the presence and absence of 1 μM 1-deoxygalactonojirimycin (Migalastat) to assess their overall stability. Supernatants from mammalian cell cultures were normalized to approximately equal activities by dilution with supernatant from a non GLA expressing culture. Diluted supernatants were added to the wells of a 96-well PCR plate (Biorad, HSP-9601). The plates were sealed and incubated at 30-54° C. for 1 h using the gradient program of a thermocycler. For the assay, 20 μL of challenged supernatant was mixed with 30 μL of 1 M citrate buffer pH 4.3 and 50 μL of 4 mM MUGal in Mcllvaine buffer pH 4.8. The reactions were mixed briefly and incubated at 37° C. for 90 minutes, prior to quenching with 100 μL of 1 M sodium carbonate. Hydrolysis was analyzed using a SpectraMax® M2 microplate reader monitoring fluorescence (Ex. 355 nm, Em. 448 nm).
Activity of WT GLA and GLA Variants on an Alternative Substrate
To confirm that improved activity in MUGal hydrolysis corresponded to more native substrates, mammalian cell-expressed GLA variants were assayed using N-Dodecanoyl-NBD-ceramide trihexoside (NBD-GB3) as substrate. HEK293T culture supernatant (10 μL), 100 mM sodium citrate pH 4.8 (80 μL), and NBD-GB3 (0.1 mg/ml) in 10% ethanol (10 μL) were added to microcentrifuge tubes. Samples were inverted to mix, and incubated at 37° C. for 1 h. The reaction was quenched via addition of 50 μL methanol, diluted with 100 μL chloroform, vortexed and the organic layer was isolated for analysis. The organic phase (10 μL) was spotted onto a silica plate and analyzed by thin layer chromatography (chloroform:methanol:water, 100:42:6), detecting the starting material and product using a 365 nm UV lamp. Significant conversion was observed only with SEQ ID NO:13, confirming that the variant exhibits improved activity, as compared to the WT GLA.
Specific Activity of GLA Variants
GLA variants purified as described in Example 4, were evaluated for their specific activity. Between 0-0.25 ng of purified enzyme was added to 4 mM MUGal in Mcllvaine buffer pH 4.8 (final pH of 4.8). Samples were incubated for 60 min at 37° C. and quenched via addition of 100 μL of 1 M sodium carbonate. Hydrolysis was analyzed using a SpectraMax® M2 microplate reader monitoring fluorescence (Ex. 355 nm, Em. 448 nm), and correlated to absolute amounts of 4-methylumbelliferone through the use of a standard curve.
pH Stability of Purified GLA Variants Over Time
To confirm that purified GLA variants show the desired pH stability observed after expression in yeast, WT GLA (SEQ ID NO:5) and SEQ ID NO:42 were incubated in acidic or basic buffers and analyzed for residual activity. GLA variants (200 ng) were added to Mcllvaine buffer pH 4.1 or 7.5 and incubated for 0-24 h at 37° C. Samples (50 μL) were added to a mixture of 25 uL 1M citric acid pH 4.3 and 25 μL of 4 mM MUGal in Mcllvaine buffer pH 4.8, and incubated at 37° C. for 1 h. Samples were quenched with 100 μL of 1 M sodium carbonate, diluted 1:4 in 1 M sodium carbonate and analyzed by fluorescence spectroscopy (Ex. 355, Em. 448). SEQ ID NO:42 was considerably more stable under both acidic and basic challenge conditions confirming that stability advances developed in yeast translated to the protein expressed in mammalian cells (See
Thermostability of Purified GLA Variants Expressed in HEK293T Cells
The thermostability of WT GLA (SEQ ID NO:5) and SEQ ID NO:42 were determined to assess their overall stability. Purified enzyme as described in Example 4 was diluted to 20 μg/ml in 1× PBS with 1× Sypro Orange (Thermo Fischer Scientific), and added to a 96-well PCR plate (Biorad, HSP-9601). The plates were heated from 30 to 75° C. at 0.5° C./min on a RT-PCR machine and Sypro Orange fluorescence was monitored. Under these conditions WT GLA melted at 37° C., while SEQ ID NO:42 melted at 55° C.
Serum Pharmacokinetics of Purified GLA Variants
Purified GLA variants produced as described in Example 4 were assessed for stability in the serum of live rats. WT GLA (SEQ ID NO:5) or SEQ ID NO:42 at 1 mg/ml were administered intravenously at 1 ml/kg to three naïve jugular vein cannulated Sprague-Dawley rats (7-8 weeks old) each. Prior to administration and at 5, 15, 30, 60, 120, and 240 minutes post-administration, 200 of blood was collected from each rat in an EDTA tube and centrifuged at 4° C. and 6000 rpm to generate >80 μL of serum per sample. Samples were frozen and stored on dry ice prior to analysis. For analysis, serum (10 μL) was added to 40 μL of 5 mM MUGal in Mcllvaine buffer pH 4.4, and incubated at 37° C. for 1 h. Samples were quenched with 50 μL of 1 M sodium carbonate, diluted 1:100 in 1 M sodium carbonate and analyzed by fluorescence spectroscopy (Ex. 355, Em. 448). Four hours post-administration SEQ ID NO:42 retained 15.3% of maximal activity, while WT GLA retained only 0.66% (See,
In this Example, experiments conducted to identify diversity that would remove predicted T-cell epitopes from GLA are described.
Identification of Deimmunizing Diversity:
To identify mutational diversity that would remove T-cell epitopes, computational methods were used to identify GLA subsequences that were predicted to bind efficiently to representative HLA receptors. In addition, experimental searches for amino acid mutations were conducted, particularly for mutations that do not affect GLA activity (e.g., in the assays described in Example 2). The amino acid sequences of active variants were then analyzed for predicted immunogenicity using computational methods.
Computational Identification of Putative T-Cell Epitopes in a WT GLA:
Putative T-cell epitopes in a WT GLA (SEQ ID NO:5) were identified using the Immune Epitope Database (IEDB; Immune Epitope Database and Analysis Resource website) tools, as known in the art and proprietary statistical analysis tools (See e.g., iedb.org and Vita et al., Nucl. Acids Res., 38(Database issue):D854-62 [2010]. Epub 2009 Nov. 11]). The WT GLA was parsed into all possible 15-mer analysis frames, with each frame overlapping the last by 14 amino acids. The 15-mer analysis frames were evaluated for immunogenic potential by scoring their 9-mer core regions for predicted binding to eight common class II HLA-DR alleles (DRB1*0101, DRB1*0301, DRB1*0401, DRB1*0701, DRB1*0801, DRB1*1101, DRB1*1301, and DRB1*1501) that collectively cover nearly 95% of the human population (See e.g., Southwood et al., J. Immunol., 160:3363-3373 [1998]), using methods recommended on the IEDB website. Potential T-cell epitope clusters contained within the enzyme (i.e., sub-regions contained within GLA which have an unusually high potential for immunogenicity) were identified using statistical analysis tools, as known in the art. The identified T-cell epitope clusters were screened against the IEDB database of known epitopes. These screens identified five putative T-cell epitopes in the WT enzyme. These epitopes are referred to as TCE-I, II, III, IV, and V below.
Design of Deimmunizing Libraries:
First, the sequences of active GLA mutants identified in Example 2 are assessed for the presence of T-cell epitopes. Mutations identified to potentially reduce binding to the HLA-DR alleles are incorporated into a recombination library. Additional libraries are prepared using saturation mutagenesis of every single amino acid within the five T-cell epitopes. Hits from these libraries are subjected to further rounds of saturation mutagenesis, HTP screening, and recombination to remove all possible T-cell epitopes.
Construction and Screening of Deimmunizing Libraries:
Combinatorial and saturation mutagenesis libraries designed as described above were constructed by methods known in the art, and tested for activity in an unchallenged assay as described in Example 2. Active variants were identified and sequenced. Their activities and mutations with respect to WT GLA are provided in the table below.
Identification of Deimmunizing Diversity:
Active variants were analyzed for their levels of predicted immunogenicity by evaluating their binding to the eight common Class II HLA-DR alleles as described above. The total immunogenicity score and immunogenic hit count are shown in Table 7.1. The total immunogenicity score (TIS) reflects the overall predicted immunogenicity of the variant (i.e., a higher score indicates a higher level of predicted immunogenicity). The immunogenic “hit count” (IHC) indicates the number of 15-mer analysis frames with an unusually high potential for immunogenicity (i.e., a higher score indicates a higher potential for immunogenicity). Mutations resulting in a lower total immunogenicity score and/or an immunogenic hit count less than that of the reference sequence were considered to be potential “deimmunizing mutations”. A collection of the most deimmunizing mutations were recombined to generate a number of variants that were active and predicted to be significantly less immunogenic than WT GLA. In the following Table, total immunogenicity score (TIS) and immunogenic hit count (IHC) are provided.
While the invention has been described with reference to the specific embodiments, various changes can be made and equivalents can be substituted to adapt to a particular situation, material, composition of matter, process, process step or steps, thereby achieving benefits of the invention without departing from the scope of what is claimed.
For all purposes in the United States of America, each and every publication and patent document cited in this application is incorporated herein by reference as if each such publication or document was specifically and individually indicated to be incorporated herein by reference. Citation of publications and patent documents is not intended as an indication that any such document is pertinent prior art, nor does it constitute an admission as to its contents or date.
The present application is a Divisional application that claims priority to co-pending U.S. patent application Ser. No. 15/529,383, filed May 24, 2017, which is a national stage application filed under 35 USC § 371 and claims priority to PCT International Application No. PCT/US2015/063329, filed Dec. 2, 2015, which claims priority to U.S. Prov. Pat. Application Ser. No. 62/095,313, filed Dec. 22, 2014, and U.S. Prov. Pat. Application Ser. No. 62/216,452, filed Sep. 10, 2015, all of which are hereby incorporated by reference in their entireties for all purposes.
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| Number | Date | Country | |
|---|---|---|---|
| 20200405826 A1 | Dec 2020 | US |
| Number | Date | Country | |
|---|---|---|---|
| 62095313 | Dec 2014 | US | |
| 62216452 | Sep 2015 | US |
| Number | Date | Country | |
|---|---|---|---|
| Parent | 15529383 | US | |
| Child | 16985788 | US |
