Claims
- 1. A compound selected from the compounds of the general formula
- X.sup.1 -X.sup.2 -Gly-Asp-X.sup.3 -X.sup.4 (I)
- in which:
- X.sup.1 is selected from the group consisting of hydrogen and a N-protecting group,
- X.sup.2 is selected from a residue of L-Arg, D-Arg, L-Orn, D-Orn, N-aminocarbonyl -L-Orn, N-aminocarbonyl-D-Orn, L-Lys and D-Lys,
- X.sup.3 is selected from a residue of L-Trp, D-Trp, L-Leu, D-Leu, L-Ile, and D-Ile, and
- X.sup.4 is selected from the group consisting of --OH, --NH.sub.2, --OR.sup.1 in which R.sup.1 is C.sub.1-4 alkyl, and NHR.sup.2 in which R.sup.2 is C.sub.1-4 alkyl.
- 2. Peptide of the formula
- H-Arg-Gly-Asp-Trp-OH.
- 3. A therapeutic composition for the treatment and the prevention of thromboses comprising an effective amount of a compound as claimed in claim 1 in admixture with a pharmaceutically acceptable excipient.
- 4. A composition as claimed in claim 3, in which the compound is
- H-Arg-Gly-Asp-Trp-OH.
- 5. A process for the treatment and the prevention of thromboses, which comprises administering to a human in need thereof an effective amount of a compound selected from the compounds of the general formula
- X.sup.1 -X.sup.2 -Gly-Asp-X.sup.3 -X.sup.4 (I)
- in which:
- X.sup.1 is selected from the group consisting of hydrogen and a N-protecting group,
- X.sup.2 is selected from a residue of L-Arg, D-Arg, L-Orn, D-Orn, N-aminocarbonyl -L-Orn, N-aminocarbonyl-D-Orn, L-Lys and D-Lys,
- X.sup.3 is selected from a residue of L-Trp, D-Trp, L-Leu, D-Leu, L-Ile, and D-Ile, and
- X.sup.4 is selected from the group consisting of --OH, --NH.sub.2, --OR.sup.1 in which R.sup.1 is C.sub.1-4 alkyl, and NHR.sup.2 in which R.sup.2 is C.sub.1-4 alkyl.
Priority Claims (2)
| Number |
Date |
Country |
Kind |
| 8617507 |
Dec 1986 |
FRX |
|
| 8708986 |
Jun 1987 |
FRX |
|
Parent Case Info
This application is a continuation of U.S. application Ser. No. 07/130,863 filed Dec. 10, 1987, now abandoned.
The present invention relates to new peptide derivatives possessing a platelet aggregation inhibiting activity, a process for their preparation and their uses in therapy and as diagnostic agents.
More precisely, the invention relates to peptide analogues of a sequence of fibrinogen which can be used in particular to antagonize the interaction between fibrinogen and blood platelets.
It is known that during the course of hemostatis blood platelets adhere to the sub-endothelium of the damaged vessel, secrete their granular contents after stimulation and aggregate together to form a platelet thrombus The aggregation depends on contacts which are established between membranes of adjacent platelets. This reaction is necessary for the cessation of bleeding. However, it exhibits numerous pathological deviations, in particular in cases of veinous or arterial thromboses, during the development of an atheroma plaque, or the formation of microthrombi which may obstruct the peripheral or cerebral microcirculation. The control and regulation of platelet aggregation are thus a major objective in the prevention of thrombosis and of atherosclerosis and numerous studies have been devoted to the research and development of molecules with platelet aggregation inhibiting properties.
Fibrinogen exercises an important role in this phenomenon. Thus, in the plasma of patients suffering from congenital afibrinogenemia, platelet aggregation is seriously reduced or absent and this deficiency is corrected by the injection of fibrinogen. Similarly, in the absence of fibrinogen washed platelets do not aggregate in the presence of ADP or epinephrine. The presence of fibrinogen is thus a necessity for the normal development of a platelet thrombus. The involvement of fibrinogen in aggregation is due to the induction of a specific receptor for this protein on the membrane of the activated platelet. All of the physiological stimuli of the platelet induce a unique class of receptor and the interaction of fibrinogen with this receptor regulates platelet aggregation. Thus, there exists a mechanism of platelet aggregation, common to all inducers, which depends on the interaction between fibrinogen and its receptor. The physiological importance of this path of platelet aggregation dependent on fibrinogen is attested to by the study of cases of Glanzmann thrombasthenia in which the platelets do not bind fibrinogen and do not aggregate in response to all of the physiological stimuli of the cell.
In summary, the fibrinogen receptor is not expressed by the circulating platelet, it is induced as soon as the cell is stimulated. This induction may be dependent on, or independent of, the secretion reaction. All of the stimuli induce the expression of the same receptor and the interaction between fibrinogen and the receptor lead directly to aggregation. The dissociation of the fibrinogen bound to the platelet results in the disaggregation of the platelets.
In this context, it is clear that if the interaction between fibrinogen and its platelet receptor could be regulated, this would constitute a means of controlling the aggregation in vitro and in vivo.
The aim of the present invention is precisely to provide new agents which make it possible to inhibit, regulate or measure selectively the pathway of aggregation dependent on fibrinogen.
Peptide sequences derived from the fibrinogen molecule have already been identified as inhibitors of the binding of this protein to platelets and thus as blockers of their aggregation. Thus, E. Plow et al. (Proc. Natl. Acad. Sci. USA 82 8057, 1985) have described the activity of the sequence Arg-Gly-Asp-Ser (RGDS)
The subject of the present invention is peptide analogues of the C-terminus of the alpha chain of fibrinogen which exhibit an inhibitory effect on the fibrinogen-platelet interaction and on platelet aggregation.
These peptide derivatives correspond to the following general formula:
In the groups X.sup.1 and X.sup.4 the amino acid residues likely to be used are in particular those of L or D-pyroglutamyl, L or D-alanyl, glycyl, L or D-prolyl, L or D-valyl, L or D-phenylalanyl, L or D-homocysteinyl, L or D-aspartyl, L or D-glutamyl, L or D-histidyl, L or D-methionyl, L or D-threonyl, L or D-seryl, L or D-cysteinyl, L or D-leucyl, L or D-arginyl, L or D-tryptophanyl, L or D-tyrosyl, L or D-lysyl and L or D-ornithyl.
In the case in which X.sup.1 =X.sup.4 =Cys the peptide derivative can be cyclized through the formation of a disulfide bridge to give the compound of formula: ##STR1##
The physiologically acceptable N-protecting groups are in particular the groups which protect against attack at the N-terminal by exopeptidases. As examples of such groups mention may be made of the acyl groups such as t-butoxycarbonyl (Boc), t-amyloxycarbonyl (t-Aoc), benzyloxycarbonyl, benzoyl, acetyl, formyl, propanoyl, butanoyl, phenylacetyl, phenylpropanoyl, cyclo-pentylcarbonyl.
The present invention also includes the equivalents of the peptide derivatives of Formula I in which each peptide bond (--CO--NH--) between two amino acid residues of the general Formula I is replaced by the following structures:
Preferred peptide derivatives are peptides of the formula:
The present invention also has as its subject:
The peptide derivatives corresponding to Formula I can be prepared in a standard manner by means of liquid or solid phase peptide synthesis by successive couplings of the different amino acid residues to be incorporated (from the N-terminus to the C-terminus in liquid phase synthesis or from the C-terminus towards the N-terminus in solid phase synthesis) and the N-termini and the reactive side chain groupings of which are blocked prior to condensation by groups such as those mentioned below:
Different types of coupling methods can be used:
1. Coupling of the residues with a carbodiimide (ex: DCC, EDC) with or without a catalyst (ex: HOBT) or any other coupling agent (ex: EEDQ).
2. Utilization of the amino acids in the form of preformed symmetrical anhydrides.
3. Utilization of the amino acids in the form of active esters (ex: p-nitrophenyl ester, HOBT ester) and coupling by the intermediary of DCC.
In solid phase peptide synthesis (SPPS) Table I below indicates the different types of resin which can be used as well as the appropriate protecting groups and methods for the different steps.
In solid phase synthesis the first amino acid (C-terminal amino acid) to be attached to the resin can either be bought commercially already bound to the support or coupled to it by the intermediary of its cesium salt (Gisin's method), its tetramethylammonium salt (Loffet's method) or by a carbodiimide.
US Referenced Citations (3)
| Number |
Name |
Date |
Kind |
|
4683291 |
Zimmerman et al. |
Jul 1987 |
|
|
4792525 |
Ruoslahti et al. |
Dec 1988 |
|
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Aug 1989 |
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Foreign Referenced Citations (3)
| Number |
Date |
Country |
| 0164654 |
Dec 1985 |
EPX |
| 0220957 |
May 1987 |
EPX |
| 2608160 |
Dec 1986 |
FRX |
Non-Patent Literature Citations (7)
| Entry |
| Boucaut, J. C., et al., "Biological Active Synthetic Peptides as Probes ofmbryonic Development: A Competitive Peptide Inhibitor of . . . ", Chemical Abstracts, vol. 102, p. 428, No. 21570a (1985). |
| Chen, W. T., et al., "Regulation of Fibronectin Receptor Distribution by Transformation, Exogenous Fibronectin, and Synthetic Peptides", Chemical Abstracts, vol. 106, p. 353, 1987. |
| Ruoslahti, R. et al., Falk Symposium, 43 (Modulation Liver Cell Expression), pp. 239-244, 1987. |
| Alberts, B. et al., Molecular Biology of the Cell, Garland Publishing, Inc., pp. 59, 1983. |
| Pierschbacher, M. et al., Journal of Biological Chemistry, 262(36): 17294-17298, 1987. |
| Dayoff, M., Atlas of Protein Sequence and Structure, vol. 5: 89-99, 1972. |
| Proc. Natl. Acad. Sci. U.S.A., vol. 82, pp. 8057-8061, Dec. 1985, Plow et al. |
Continuations (1)
|
Number |
Date |
Country |
| Parent |
130863 |
Dec 1987 |
|
Patent Grant
5100875
