Proteolytic enzyme activities in a variety of snake venoms

Abstract

Summary The trypsin-like activity of twenty-five Crotalidae and Viperidae venoms was investigated using p -toluenesulfonyl- l -arginine methyl ester (TAME) and N -benzoyl- l -arginine ethyl ester (BAEE), with and without soybean trypsin inhibitor and ovomucoid. Since hydrolysis of these substrates was not inhibited in the presence of the two inhibitors, the enzymes present in Crotalidae and Viperidae venoms are not identical to trypsin. Chymotrypsin-like activity of thirty-three Crotalidae, Viperidae, and Elapidae venoms was tested using N -benzoyl- l -tyrosine ethyl ester and N -acetyl- l -tyrosine ethyl ester. Most of the venoms did not hydrolyze these substrates. Apparently, there is no chymotrypsin in these snake venoms. Thrombin-like activity was tested using both TAME and BAEE. None of the Crotalidae and Viperidae venoms formed fibrin from fibrinogen even though they hydrolyzed TAME. It is also concluded that the proteolytic enzymes in Crotalidae and Viperidae venoms are similar to each other, while those of Elapidae venoms are different. It is apparent from this investigation that there are new types of proteolytic enzymes whose nature needs further clarification.