Chapter 55 - Conus Snail Venom Peptides

Abstract

This chapter focuses on the venomous peptides derived from cone snail. Cone snails are a large genus of venomous predators. They comprise only a minor fraction of the total biodiversity of molluscs. Peptides from Conus venoms are generally small (10–30 amino acids) and disulfide–rich, often with unusual post–translationally modified amino acids. Most Conus peptides target ligand-gated or voltage-gated ion channels, or G-protein-coupled receptors. Conotoxins are the major peptides derived from Conus venoms. The first conotoxins were purified and characterized from the venom of Conus geographus, a dangerous species of Conus that has caused human fatality. Experimental studies showed that conotoxins caused paralysis in fish and mice, and were shown to target ion channels important for neuromuscular transmission. Peptides from a given conotoxin superfamily with the same Cys pattern are believed to have generally similar three-dimensional structures. Conus peptide superfamilies are subdivided into several discrete families. The salient feature that distinguishes the different conotoxin families belonging to the same superfamily is pharmacological specificity.