Conotoxins

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As conotoxins refers to a group of toxins from the venom of sea snails of cone snails genus of Conus can be isolated. A number of conotoxins can also be produced synthetically. Most conotoxins are short peptides and consist of 10 to 30 amino acids . In April 2010, the Conoserver database had 3,369 entries from 89 species.

A high cysteine ​​content is characteristic of conotoxins. The disulfide bridges that exist between the cysteines largely determine the structure and thus also the effectiveness of the toxins. Thanks to their small size, the toxin molecules can quickly penetrate the tissue fluid of the prey of Conus snails and quickly paralyze them. Human deaths have also become known after contact with Conus snails ( Conus geographus ).

toxicology

The effect of conotoxin is based on the binding to the ion channels between nerve cells; the nerve conduction is interrupted and the transmission of nerve impulses is prevented. Remarkably many conotoxins is the high specificity with which they recognize their target molecules, so here the ion channels or neurotransmitter - receptors . The high specificity makes conotoxins interesting active ingredients for medical use. The peptide ω-conotoxin discovered in Conus purpurascens , for example, specifically blocks N-type calcium channels in humans and thus prevents the influx of calcium and the release of neurotransmitters at the synapse . The peptide can therefore block the transmission of pain stimuli and contribute to pain relief even in cases where morphine is not sufficiently effective. The 25 amino acid peptide (ω-conotoxin-MVIIA, UniProt P05484 ) obtained from Conus magus is approved as a synthetic analogue for combating severe chronic pain in adults under the name ziconotide . Another Conus peptide that is in clinical development is Contulakin-G (Conantokin), which was isolated from Conus geographus .

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