Conotoxins as Tools in Research on Nicotinic Receptors

Abstract

Conopeptides or conotoxins, the venom peptides produced by predatory marine snails (genus Conus), typically consist of about 10-50 amino acid residues. They have considerably diverged and are practically classified into superfamilies. Members of conotoxin superfamilies are greatly selective antagonists of ligand-gated and voltage-gated ion channels. This chapter describes the structural and functional diversity of conotoxins that influence neurotransmission through their action on the nicotinic receptors. Conopeptide diversity has been shown to occur in members of different superfamilies with the nicotinic receptors as their molecular targets. In many cases, the conotoxins exhibit extremely high specificity towards nicotinic receptor subtypes making them useful tools for studying the structure and physiological functions of the receptors. As the functional diversity of conotoxins continues to be investigated, the pairwise combinations of conotoxins and nicotinic receptors have shown important applications in neuropharmacology and therapeutics.