About conotoxins

Introduction

Marine gastropods, better known as cone snails from Conus genus, produce a mixture of venomous peptides for capturing prey, defense and deterring competitors. These conopeptides can generally be divided into two broad classes, the disulfide rich conotoxins which contain two or more disulfide bonds and the disulfide poor which contain one or no disulfide bond. Conotoxins are small highly constrained peptides ranging from 10-40 amino acids in length. Each cone snail may contain up to 200 peptides and given there are over 700 cone snail species, the library of bioactive peptides is huge (with a broad estimate of thousands of unknown conopeptides [ref]). The targets for these toxins are a range of membrane bound receptors and ion channels, thus exhibiting great potential as therapeutics themselves or as leads to therapeutics.

To capture their preys, which comprise molluscs and fish, or to repel predators, cone snails have developped a rich mixture of peptides, or conopeptides. These peptides act potently and with high specificity on ion channels, receptors and transporters of the nervous system. The tenths of thousands of different conopeptides that are predicted to exist attract considerable scientific and commercial interest.

From an evolutive and environmental point of view, conopeptides could help to understand how the toxin repertoire of one species evolved to adapt to their molecular targets in another species. A scientific applications is the use of conopeptides in neurophysiological studies to probe specifically neuroreceptor isoforms. Channels and receptors of the nervous systems are well conserved accross species, and several peptides that show activity in humans are drugs or are developped as drug leads.