Isolation, Biochemical and Pharmacological Characterization of a Prothrombin-Activating Principle from Echis Carinatus Venom / Isolierung sowie biochemische und pharmakologische Charakterisierung eines Prothrombin-aktivierenden Prinzips aus Echis carinatus-Gift
Echis carinatus venom promotes coagulation in vitro by a thromboplastinlike, Ca++ -independent action upon the prothrombin complex. Its application in vivo results in consumption coagulopathy (Kornalik ). 60 fold purification of the prothrombin-activating principle has been achieved by chromatography on calcium hydroxyapatite and DEAE cellulose. The resulting material appears homogeneous in cellogel electrophoresis; by immunoelectrophoresis and electrophoresis in polyacrylamide gel, however, two faint additional components can be demonstrated. The protein is acidic (isoelectric point below 5); a molecular weight of 86000 has been calculated from elution behaviour on calibrated sephadex G 100 columns. Its high lability precludes working outside the pH range between 6 and 10. The promotion of coagulation may be connected with its weak proteolytic activity. The procoagulant is not inhibited by diiso-propylfluorophosphate, soyabean inhibitor or trasylol. The plasma of Marcumar®-treated animals is resistant against it.—S.c. injection of 0.025–0.05 μg/rat depletes the blood from fibrinogen, which is evident from the prolonged thrombin time. like in vitro, the in vivo actitivy of the procoagulant is about 50–100 times higher than that of crude venom. Restitution of fibrinogen level depressed by sublethal doses lasts for about 7–9 days.
- 1.Kornalik, F.: Fol.haemat. (Lpz.) 80, 73 (1963).Google Scholar