Studies on enzymic Properties of the Thrombin-Like Enzymes From Trimeresurus stejnegeri Venom

In this paper,enzymic properties of two thrombin-like enzymes (principle Ⅰ and principle Ⅱ) was reported.The results showed that principle Ⅰ and principle Ⅱ could convert human fibrinogen into fibrin,both had arginine esterase activity and could hydrolyze Bz-Phe-Val-Arg-PNA which was special substrate of thrombin.Principle Ⅰ and principle Ⅱ had an activated fibrinolysis and principle Ⅱ also had a direct fibrinolysis as showed by plate method of fibrin,principle Ⅰ and principle Ⅱ could slowly degrade the α chain of fibrinogen and principle Ⅰ also could further degrade the β chain of fibrinogen.The active center of principle Ⅰ is a serine protease and has a glycosyl site.The optimal temperature was 50℃ and the optimal pH was 8.6 for principle Ⅰ to hydrolyze BAEE.