Thromb Haemost 1991; 66(03): 300-305
DOI: 10.1055/s-0038-1646411
Review Article
Schattauer GmbH Stuttgart

Effect of the Hirudin Carboxy-Terminal Peptide 54-65 on the Interaction of Thrombin with Platelets

Martine Jandrot-Perrus
The Laboratoire de Recherche sur l'Hémostase et la Thrombose, Faculté Xavier Bichat, Paris, France
,
Marie-Geneviève Huisse
The Laboratoire de Recherche sur l'Hémostase et la Thrombose, Faculté Xavier Bichat, Paris, France
,
John L Krstenansky
*  The Merrell Dow Research Institute, Cincinnati, OH, USA
,
Annie Bezeaud
The Laboratoire de Recherche sur l'Hémostase et la Thrombose, Faculté Xavier Bichat, Paris, France
,
Marie-Claude Guillin
The Laboratoire de Recherche sur l'Hémostase et la Thrombose, Faculté Xavier Bichat, Paris, France
› Author Affiliations
Further Information

Publication History

Received 18 December 1990

Accepted 04 March 1991

Publication Date:
25 July 2018 (online)

Summary

The carboxy-terminal region of hirudin (residues 54-65) has previously been shown to inhibit thrombin clotting activity without binding to the catalytic site of the enzyme. In the present study, the effect of hirudin 54-65 on thrombin interaction with specified platelet proteins has been investigated. Hirudin 54-65 was found to inhibit thrombin-induced platelet aggregation and secretion in a dose-dependent manner. Substitution of either Phe56, Glu57, Ile59, Pro60 or Leu64 showed that these residues were critical for inhibition of thrombin-induced platelet activation whereas sulfation of Tyr63 increased the inhibitory potency of the peptide. Hydrolysis of glycoprotein V, a platelet membrane substrate for thrombin, was only partially inhibited by hirudin 54-65. Although hirudin 54-65 did not decrease the amount of thrombin bound to platelets during cross-linking experiments, it was found to inhibit the specific binding of thrombin to platelet glycoprotein Ib. Since the carboxy-terminal region of hirudin has previously been reported to bind near the trypsin-catalyzed β cleavage site, we have analyzed the consequences of a to β-thrombin conversion on both thrombin-hirudin 54-65 interaction and thrombin activity toward platelets. The β cleavage induced a decrease in the affinity of thrombin for both glycoprotein Ib and hirudin 54-65. Altogether, our results indicate that thrombin recognition sites for hirudin 54-65 and platelet membrane glycoprotein Ib share common structures located near the β cleavage site at Arg 73 on the thrombin B chain.