Snake Venoms. Purification, some Properties of Two Phospholipases A2(CM-I and CM-II) and the Amino-Acid Sequence of CM-II fromBitis nasicornis(Horned Adder) Venom

Abstract

Two phospholipases A2, CM-1 and CM-2, were purified from B. nasicornis venom by gel filtration on Sephadex G-50, followed by ion-exchange chromatography on CM-cellulose. Both enzymes comprised 119 amino acids, including 12 half-cystine residues. The primary structure of CM-2 was elucidated. The sequence and invariant amino acid residues of CM-2 resembled those of phospholipases A2 from other venoms of Viperidae and Crotalidae (group 2) snake venoms. CM-1 and CM-2 contained a single His residue which was probably located at the active center (His-47). CM-1 and CM-2 were relatively nontoxic.