title: Amino acid sequence of cytotoxin IIa isolated from the venom of the Indian cobra (Naja naja).
abstract: A cytotoxic basic polypeptide, designated as cytotoxin IIa, was purified to homogeneous state from the venom of the Indian cobra (Naja naja) by a combination of gel filtration on Sephadex G-50, CM-cellulose chromatography, and fast protein liquid chromatography. Cytotoxin IIa is a single polypeptide consisting of 60 amino acid residues with four intramolecular disulfide linkages. The toxin showed high cytotoxicity toward Yoshida sarcoma and ascites hepatoma cells as did cytotoxins I and II isolated from the same venom. Analysis of the amino acid sequence revealed that cytotoxin I, IIa, and II are highly homologous in their primary structures and that cytotoxin IIa differs from cytotoxin I only in having Phe 25 and Val 52 in place of Tyr 25 and Glu 52 residues.
mesh_terms: D000595:Amino Acid Sequence; D000596:Amino Acids / Q000032:analysis; D000818:Animals; D003603:Cytotoxins / Q000302:isolation & purification; D004546:Elapid Venoms / Q000302:isolation & purification
chemical_list: D000596:Amino Acids; D003603:Cytotoxins; D004546:Elapid Venoms