Purification, some properties and the primary structures of three reduced and S-carboxymethylated toxins (CM-5, CM-6 and CM-10a) from Naje haje haje (Egyptian cobra) venom.

Three reduced and S-carboxymethylated toxins (CM-5, CM-6 and CM-10a) were purified from Naja haje haje (Egyptian cobra) venom. Whereas toxin CM-5 comprises 71 amino acid residues and five intrachain disulphide bridges, toxins CM-6 and CM-10a contain each 61 residues and four disulphide bridges. The complete primary structures of the three toxins have been established. The toxicity, the immunochemical properties, the sequence and the invariant amino acid residues of toxin CM-5 resemble the properties of the long neurotoxin group, while those of toxin CM-6 and CM-10a are related to the short neurotoxin group. Further, the sequences of the three toxins from Naja haje haje venom reveal a high degree of homology with those of the corresponding neurotoxins isolated from Naja haje annulifera or Naja nivea venoms.