Cone snail

Conotoxins are the venoms of the marine cone snails. The >500 Conus species produce >10,000 different toxins. All are cysteine-rich peptides of 10-30 amino... 

When a cone snail envenomates its prey, the latter is invariably paralyzed. In all cases, the paralytic toxins in the venom ("conotoxins") appear to be small peptides, most commonly with 3 disulfide bonds (although conotoxins with 2 or 4 S-S bonds... 

The a -, /z-, and a-conotoxins are the best characterized of the peptides isolated from Conus venoms so far. However, a large number of other peptides are found in these venoms. These comprise both paralytic toxins to immobilize the prey of the cone snail, and other biologically active peptides which are not themselves directly paralytic. Only the briefest overview of these peptide components will be presented here. 

In the fish-hunting cone snail venoms, a- and w-conotoxins are ubiquitously distributed. As noted above, z-conotoxins have only been found in one species. Conus geographus. In addition to these three well-characterized classes, however, a fourth class of paralytic conotoxins has been found. In contrast to the a-, z-, and... 

Cone snails have generated a remarkably wide array of toxins. A variety of data suggest that this genus may use novel mechanisms for evolving diverse cysteine-rich peptides. 

The cone snails constitute one of the largest groups of animals that use venoms as their primary weapon for capturing prey (300—500 species). Furthermore, they have successfully envenomated a much wider variety of prey than has been observed for most venomous animal genera. 

The cone snails from all marine environments (Phylum Mollusca, Class Gastropoda, Order Sorbeoconcha) represent a large genus of approximately 700 carnivorous predator species (Figure 6). They are classified... 

Figure 6 Venomous marine cone snails, (a) Geography cone Conus geographus (Public domain)) (b) Queen Victoria cone [Conus victoriae)-, (c) cloth of gold cone [Conus textile), (d) marble cone [Conus marmoreus (Public domain)) (e) closing view of proboscis with toxoglossan cone snail (f) microscope picture of toxoglossan from Conus consors. Photos (b), (c), (e),...

Prialt [Fig. 6] is a synthetic copy of a toxin from the Magician s cone snail. Conus magus, a mollusk from the Indo-Pacific region. This is also one of the first pharmaceuticals that demonstrate the promise that marine life, particularly invertebrates, holds for drug developers. 

Conotoxins are small (10-30 amino acids), disulphide-rich, conformationally constrained peptides produced by marine mollusks such as cone snails. The fish-hunting snails, in particular Conus geographus, have been extensively studied. Depending upon the arrangement of disulphide bonds and the number of residues between cysteines, five or more classes of conotoxin can be structurally identified ... 

Omega conotoxin (co-CTX-GVIA) Blocks N-type channel Pacific cone snail... 

The genus Conus comprises approximately five hundred species of predatory cone snails and is therefore, one of the largest, if not the largest, single genus of marine animals alive. Each species of snail produces a unique venom with between 50 and 200 components. These sulfur-rich peptides or conotoxins are neuropharmacologically active and modulate ion channel function [235]. Any attempt to deal with these toxins within this review would not be feasible and the reader is referred to other excellent reviews on the subject [235,236]. 

Predatory cone snails produce a variety of polypeptide toxins... 

Peptides from cone snails and spiders - molecular probes for N- and P/Q- type Ca2+ channels... 

Cone snails are found in tropical waters, often in the neighborhood of coral reefs. These molluscs produce a complex venom delivered through a specialized radular tooth that serves as a harpoon to immobilize their prey (Olivera et al., 1990 1991). Complete immobilisation of the prey takes only a few seconds (Terlau et al., 1996). The venom from a single cone snail can contain up to 200 different biologically-active components (review Shen et al., 2000). The primary structure of the naturally-occurring co-conopeptides derived from several species of Conus are... 

Bacteria, protozoa, and venomous animals synthesize numerous toxins that are used to kill their prey or to defend themselves. Sea anemones, jellyfish, cone snails, insects, spiders, scorpions, and snakes all make potent and highly specific neurotoxins. Plants form a host of alkaloids and other specialized products, some of which are specifically neurotoxic and able to deter predators. More than 500 species of marine cone snails of the genus Conus synthesize a vast array of polypeptide toxins (conotoxins), 487-489 some with unusual posttranslational modifications.490 491 The slow-moving snails are voracious predators that use their toxins, which they inject with a disposible harpoonlike tooth,492 to paralyze fish, molluscs, or worms.493... 

One major recent development in the area of natural products is the discovery and subsequent medicinal application of the toxic peptides from cone snails. These Conus peptides, several of which contain a 6-bromotryptophan amino acid, are finding utility for the treatment of neuropathic pain and other neurological conditions (1074-1078). For example, oo-conopeptide MVIIA (Ziconotide, trade name Prialt) has been approved by the US FDA since 2004 for the treatment of severe pain. It is estimated that the 500-700 species of cone snails (Conus genus) contain... 

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