Enzymological characterization of Flla, a fibrinolytic enzyme from Agkistrodon acutus venom

• 来源期刊: 中国药理学报(英文版)
• 关键词: snake venoms Agkistrodon acutus fibrinolysis metalloproteinase
• 年，卷（期）: 2005,（12）
• 页码范围: 1474-1478
• 页数: 5页
• 语种: 英文

摘要

Aim: To study the enzymological characterization of a fibrinolytic enzyme (FⅡa)from Agkistrodon acutus venom. Methods: The fibrinogenolytic effect and the influences of several protease inhibitors, chelating agents, and metal ions on fibrinogenolytic activity were visualized by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. The metal content of FⅡa was determined by atomic absorption spectroscopy. Results: After incubation with EⅡa (0.25 g/L), Aα-, Bβ-and γ-chains of fibrinogen disappeared within 5 min, 30 min, and 8 h, respectively.The molecular weights of major degradation products were 45 000 and 41 000,which were different from those bands produced by plasmin. The fibrinogenolytic activity of FⅡa was strongly inhibited by ethylenediamine tetraacetic acid (EDTA),ethyleneglycol tetraacetic acid (EGTA), dithiothreitol and cysteine, but not by phenylmethyl-sulfonyl fluoride and soybean trypsin inhibitor. Zinc (3171±25mg/kg), potassium (489± 17 mg/kg) and calcium (319± 13 mg/kg) were found in FⅡa.Zn2+, Ca2+ and Mg2+ could recover the fibrinogenolytic activity of FⅡa, which was inhibited by EDTA. Only Ca2+ could recover the fibrinogenolytic activity inhibited by EGTA. Conclusion: FⅡa can degrade the Aα-, Bβ- and γ-chains of fibrinogen.EⅡa is a metalloproteinase, and Zn2+, Ca2+, and disulfide bonds are necessary for its fibrinogenolytic activity.