Thrombin-like snake venom serine protease that cleaves Arg-Gly bonds in alpha-chain of fibrinogen (FGA). Induces temporary episodes of opisthotonos and rapid rolling around the long axis of the animal (gyroxin-like effect), when injected into the tail veins of mice (0.143 ug/g mouse). Selective cleavage of Arg-|-Xaa bond in fibrinogen, to form fibrin, and release fibrinopeptide A. The specificity of further degradation of fibrinogen varies with species origin of the enzyme. Inhibited by PMSF and benzamidine. Its clotting effect is strongly inhibited by antibothropic serum. Is not inhibited by heparin. Optimum pH is 7.0-8.5. Monomer. Expressed by the venom gland. Glycosylated. Does not activate factor XIII (F13A) and is unable to release kinins from heat-treated bovine plasma. Does not cleave beta-chain of fibrinogen (FGB) (PubMed:16481207). Belongs to the peptidase S1 family. Snake venom subfamily.