Snake venom serine protease that degrades preferentially beta-chain of fibrinogen (FGB). Its activity is inhibited by PMSF and p-nitrophenyl-p-guanidinobenzoate (NPGB). Monomer. Expressed by the venom gland. Does not degrade the gamma-chain of fibrinogen, does not activate plasminogen and does not possess fibrinogen-clotting activity. Belongs to the peptidase S1 family. Snake venom subfamily.