Partial purification and some properties of the blood-clotting factor from the venom of Bothrops jararaca

Abstract

The pH optimum for the blood-clotting activity of the venom of Bothrops jararaca was about 7.0; at this pH the enzyme was more active in cacodylate buffer, being inhibited by phosphate, 2-amino-2-hydroxymethylpropane-l,3-diol (tris)-hydrochloric acid, citrate and tris maieate. The clotting enzyme is thermolabile, its activity being reduced to about 1/10 when it is rapidly heated to 87[degree]. The venom fraction precipitated between 0.60 and 0.65 saturation with (NH4)2SO4 had a clotting activity about twice as high as that of the crude venom; its benzoylarginine-amidase specific activity was also about twice that of the crude venom; its caseinase specific activity was about 1/6 of that of the crude venom. Fractional reprecipitation of the venom fraction precipitated between 0.60 and 0.65 saturation with (NH4)2SO4 followed by electrophoresis on a starch column produced a clotting fraction about 4 times as active as the crude venom. The clotting enzyme was different from the 2 other proteolytic enzymes found in the venom, namely "caseinase" and Bothrops protease A.