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Abstract

Snake venoms display a variety of proteins and peptides able to affect thrombosis and hemostasis, including serinoproteases which constitute 20% of the total proteins of the venom. A serinoprotease from B. pirajai snake venom was isolated and biochemically characterized. It was named piraserbin. Its high purity level was shown by SDS polyacrylamide gel electrophoreses under reducing conditions, showing a single chain with Mr 37,500, 12% neutral carbohydrate and pI 4.6. Its minimum coagulant dose was 1.75m g and its fibrinogenolytic activity was mainly upon the a chain of fibrinogen, and its fibrinolytic activity was observed only at high enzyme dose (100m g). It showed a high esterase activity upon TAME (15U/mg) and high amidolytic activity upon synthetic peptides S2302 (H-D-Pro-Phe-Arg-pNA-2 HCl) which is a substrate for plasma calicrein, and S 2238 (H-D-Phe-Pip-Arg-pNA-2HCl), substrate for thrombin. When assayed for cinin release, it did not show any activity. It was however able to induce platelet aggregation of 90% at 20m g/ml. N-terminal sequencing reveated 90% homology with crotalase (calicrein-like serinoprotease from Crotalus adamanteus venom).