Blood-clotting Activity of the Venom of Bothrops jararaca

Abstract

THE well-known blood-clotting activity of the venom from snakes of various species of the genus Bothrops has been attributed to its proteolytic activity¹, although Michl² (using paper electrophoresis) and Holz and Raudonat³ (using fractional precipitation with ammonium sulphate) have presented evidence against this point of view. The latter authors obtained a fraction, which they called “Koagulin”, with a strong blood-clotting activity but only slight proteolytic activity when hæmoglobin was used as substrate. More recently, it has been shown that there exist at least two proteolytic enzymes in the venom of Bothrops jararaca: one of them is thermolabile⁴ and is precipitated at 50 per cent saturation with ammonium sulphate⁵, while the other is stable to heat⁴ and is precipitated at 70 per cent saturation with ammonium sulphate⁵. The latter enzyme has been isolated in a fairly pure state and has been called Bothrops protease A (ref. 6).