Positively charged amino acid residues located similarly in sea anemone and scorpion toxins.

摘要: Specific groups of sea anemone and scorpion toxins compete on the same pharmacological site, voltage-gated sodium channel mammal excitable membranes. However, these are two distinct protein families. Here we purified sequenced a new toxin, Bg II, highly toxic to mammals also less mutant, III. Two II models were determined from sequence homologies with toxin two-dimensional NMR structures. Only one model conformed circular dichroism data obtained was compared an x-ray structure toxin. The comparison structures shows that 5 amino acid residues located similarly in From residues, 4 basic constituting positively charged poles surface toxins. In mutant isolated, negative charge beside positive decreases toxicity. These results show could be essential for activity outline role electrostatic bonds interaction their receptor.