Computational analysis of evolutionary divergence of scorpion toxins

Conserved and consensus sequences of several members of scorpion toxin families have been analyzed. Multiple sequence alignment define the highly conserved residues that play important structural role in formation of toxin subgroups. Scorpion toxins have characteristic feature in signature pattern {(GA)}- K-C {(LIVM)}-X (2)- K- C- C-X-C) }. where lysine and cysteine residues are well conserved in the polypeptide. The toxins show two major groups, one with conserved active region GKCMNKGKC and second with CTPK. There is variability in position of lysine and arginine in different toxins. Most of the scorpion toxins contain six conserved cysteines involved in disulphide bonds. From the evolutionary analysis it is concluded that Leiurus is a primitive ancestral species from which probably various toxins have evolved during the evolution.