Amino acid sequence of a cardiotoxin-like basic polypeptide (CLBP) with low cytotoxic activity isolated from the venom of the Formosan cobra (Naja naja atra).

A cardiotoxin-like basic polypeptide, designated as CLBP, was isolated from the venom of Naja naja atra by gel filtration on Sephadex G-50 followed by CM-cellulose chromatography. The cytotoxicity toward Yoshida sarcoma cells and lethal toxicity toward mice of CLBP were both one-order lower than those of cardiotoxins and cobrotoxin, respectively. CLBP is a single polypeptide consisting of 61 amino acid residues with four intramolecular disulfide linkages. The amino acid sequence of CLBP shows a high degree of homology with those of cardiotoxins from the same venom, but differs in the 19 to 23 positions.