Effects of fused hirudin on activity of thrombin and function of platelets

摘要

Objective: To investigate whether fused hirudin peptide has both antithrombin and an-tiplatelet functions. Methods: The core region of fused hirudin was the C-terminal tail of hirudin ( hirudin_(53-64)), which could bind to the anion binding exosite (ABE) of thrombin. Arg-Pro-Pro-Gly-Phe (RPPGF) amino acid sequence, a metabolite of bradykinin, was added to the N-terminus of hirudin_(53-64). It bound to the active site of thrombin. Additionally, Arg-Gly-Asp(RGD)amino acid sequence, an inibitor of glycoprotein Ⅱ b/ Ⅲ a( GP Ⅱ b/ Ⅲ a) receptor, was linked to C-terminus of hirudin_(53-64). This 26-animo acid-fused hirudin peptide was artificially synthesized,purified and analysed. Results: Fused hirudin peptide significantly lengthened the activated partial thromboplastin time(APTT), thrombin time(TT)and prothrom-bin time(PT) and inhibited the amidolytic activity of thrombin. The ADP-induced platelet aggregation was markedly inhibited by fused hirudin peptide. Conclusion: Fused hirudin peptide has activity of antithrombin as well as antiplatelet. Therefore bifunctional anticoagulation peptide has capacity to target various components of haemostatic process and may become more powerful antithrombosis agent.