ISOLATION AND PARTIAL CHARACTERIZATION OF A PHOSPHOLIPASE-A2 FROM THE VENOM OF CROTALUS-SCUTULATUS SALVINI

A phospholipase A2 (EC 3.1.1.4) has been isolated and purified from the venom of Crotalus scutulatus salvini in 33% yield. The enzyme was homogeneous on polyacrylamide gel electrophoresis. The molecular weight of the enzyme was in the same range (30,000) whether determined by gel filtration or ultracentrifugation. On polyacrylamide gel electrophoresis, in the presence of sodium dodecyl sulphate and β-mercaptoethanol, the enzyme migrated into a single protein band with a mobility corresponding to about 14,000 molecular weight, indicating that the native enzyme was a dimer. Amino acid composition of the enzyme is reported. Two NH2-amino acid terminals were found which indicates that the dissociable monomers of the native enzyme were non-identical. Antiserum against the purified enzyme completely inhibited the phospholipase A2 activity and immunodiffusion of the antiserum against both purified phospholipase A2 and crude venom of Crotalus scutulatus salvini gave single precipitin lines indicating a lack of contaminating antigens. © 1979.