A hemorrhagic metalloprotease, named BjussuMP-I, was isolated from Bothrops jararacussu snake venom by a combination of gel filtration on Sephacryl S-200 (0.01 M Tris-HCl, pH 7.6 buffer) and Phenyl Sepharose CL-4B chromatography (0.01 M Tris-HCl plus 4 M NaCl, pH 8.6 buffer, followed by a concentration gradient from 4 to 0 M NaCl at 25 degrees C in the same buffer). BjussuMP-I is a 60 kDa protein with a pI approximately 5.5, which induced hemorrhage after intradermal injection in mice, with a minimum hemorrhagic dose of 4.0 microg. The hemorrhagic activity of BjussuMP-I was totally abolished after incubation with a chelating agent (EDTA), corroborating the metal-dependency of this effect. BjussuMP-I shows proteolytic activity on casein and fibrinogen, although having an activity lower than that of crude B. jararacussu venom and the metalloprotease neuwiedase isolated from Bothrops neuwiedi snake venom. It was recognized by anti-neuwiedase antibodies, with a reaction of partial immunologic identity. BjussuMP-I also shows bactericidal activity against Escherichia coli and Staphylococcus aureus. This is the first report on the isolation and characterization of a high molecular weight hemorrhagic metalloprotease (BjussuMP-I) from B. jararacussu venom, which may play a relevant role in local and systemic bleeding which characterizes Bothrops envenomations.