Androcin, a novel type of cysteine-rich venom peptide from Androctonus bicolor, induces akinesia and anxiety-like symptoms in mice.

Abstract

A novel type of venom peptide with six disulfide bridges, referred to as Androcin, was identified from the scorpion Androctonus bicolor using a cDNA library strategy. The amino acid sequence of Androncin displays little identity to other known peptides from scorpions. We found that the genomic sequence of Androcin consists of three exons interrupted by two introns that are localized in the signal sequence and mature peptide encoding regions, inserted in phase 2 and phase 0, respectively. This genomic organization is unique among those of the cysteine-rich peptides from scorpions described so far. The primary and secondary structures of Androcin are homologous to those of the N-terminal domains of insulin-like growth factor-binding proteins; this suggests that Androcin may block the normal function of IGFs. Toxicological analysis using the recombinant Androcin peptide revealed that Androcin is able to induce severe akinesia and anxiety-like symptoms in mice. Androcin is a novel mammalian toxin with six disulfide bridges that provides the scorpion with another tool to subdue animals.