Snake venoms. The amino-acid sequence of protein S2C4 from Dendroaspis jamesoni kaimosae (Jameson's mamba) venom.

A major component (S2C4) was purified from Jameson's mamba by gel filtration on Sephadex G-50 and ion-exchange chromatography on CM-cellulose. Protein S2C4 comprises 62 amino acid residues including 8 half-cystine residues. The complete amino acid sequence of the protein has been established. The sequence and the invariant amino acid residues of protein S2C4 resemble a short neurotoxin, a long neurotoxin, a cytotoxin and an angusticeps type protein. However, the position of its four disulphide bridges differs from those encountered in a short neurotoxin or a cytotoxin. Mixtures of protein S2C4 and angusticeps type proteins revealed a marked synergistic effect, in that their toxicity in combination was greater than the sum of their individual toxicities.