Isolation and characteristics of α-fibrinogenase venom from Naja oxiana

Abstract

Venom of the Central Asian cobra (Naja oxiana Eichwald, NO) was shown to contain proteinase activity that cleaved the fibrinogen α-chain. An electrophoretically homogeneous preparation of basic (pI ~ 10) α-fibrinogenase (α-Fg) with MW 60 kDa exhibited the maximum activity at pH 6.0–8.0. α-Fg was a metalloproteinase (activity suppressed only by EDTA) that was thermolabile; at optimum temperature of 20–40°C (heating for 15 min at 60°C led to an activity loss of 80–85%). The enzyme cleaved dose-dependently the Aα-chain. The α-chain of human fibrinogen was hydrolyzed completely in 20 min with an experimental dose of 15 μg.