Thrombin-like snake venom serine protease that specifically hydrolyzes the Aalpha chain of fibrinogen (FGA). Exhibits strong N-p-tosyl-L-arginine methyl esterase activity, and hydrolyzes tripeptide nitroanilide derivatives weakly or not at all. 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. Inactivated by antipain, PMSF, TPCK, leupeptin, pepstatin, EDTA, and E-64 (trans-epoxysuccinylleucylamido(4-guanidino)butane). Monomer. Expressed by the venom gland. Glycosylated. Belongs to the peptidase S1 family. Snake venom subfamily.