Toxinology of Marine Venomous Snails

A surprisingly large number of sea snail species are venomous. Cone snail venoms are produced in a lengthy tubular duct from a complex venom gland and form a cocktail of many toxins, particularly conotoxins which have high potency and specificity for their target specific receptors. They inhibit various channels, neuromuscular receptors or hormones of the victim, and interfere in the transmitted signals of the prey, or dissuade predators. Cone snails have an amazing ability to quickly convert between two different types of defense-evoked and predation-evoked venoms in response to defensive or predatory stimuli. Various conotoxins and conopeptides such as α-conotoxins, σ-conotoxins, ω-conotoxins, μ-conotoxins, ψ-conotoxins, τ-conotoxins, δ-conotoxins, κ-conotoxins and conkunitzins, conantokins, contryphans, Ac1 conotoxins, conoinsulins, granulin-like conotoxins from conoides; augerpeptides derived from the venom peptide family Terebridae; turripeptides from the venom peptide family Turridae; crassipeptides venom peptides from Crassispirids; clathurellipeptides from venomous micro-conoides Clathurellidae, and other toxins such as RFamide peptides and endogenous neuropeptide-like peptides such as conopressins, as well as contulakins have been found in cone snail venoms, which have demonstrated remarkable biological and pharmacological functions. Given the approval of some conotoxins, such as the analgesic medication ziconitide (Prialt®) in clinical trials as well as their biomedical potential, current research has focused on these toxins. The use of integrated venomics approaches has dramatically accelerated the detection of conotoxin sequences. It is anticipated that a better understanding and identification of conotoxins and other toxins derived from other sea snails will lead to their use for the treatment of diseases to which humans have succumbed.