Biologically active peptides from Bothrops jararacussu venom.

The venom of the Brazilian snake Bothrops jararacussu, was found to contain peptides capable of potentiating the smooth muscle contracting activity of bradykinin (BK). Chromatographic separation on Sephadex G-25 and Sephadex G-10 respectively, yielded an active peptide which at a concentration of 0.6 micrograms/ml doubled the effect of a single dose of BK on the isolated guinea-pig ileum. HPLC chromatography showed this material to contain one major and 4 minor components. The active peptide was 2-3 times more active than Captopril in the potentiation of the effects of BK on rat arterial blood pressure and on the isolated guinea pig ileum. It also showed marked capacity to inhibit angiotensin I-converting enzyme.