Hydrolyzes alpha and beta chains of human fibrinogen and human fibrin. No activity against the gamma chain of human fibrinogen, human thrombin, bovine serum albumin, ovalbumin and hemoglobin. Has anticoagulant activity on human plasma and protects mice against death due from experimentally induced platelet thromboembolism with an ED(50) of 40 ug/kg. Binds 1 zinc ion per subunit. On the 2D-gel the determined MW is: 43 kDa.