Contryphan
| Contryphan | |||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|
| |||||||||||
The contryphans (conus + tryptophan) are a family of
disulfide bond. In addition, contryphans undergo an unusual degree of post-translational modification
including
amidation of the C-terminus, and proline hydroxylation.[2] In the broader scheme of genetic conotoxin classification, contryphans are members of "Conotoxin Superfamily O2."[3]
Family members
Contryphan family members include:
| Peptide | Sequence | Species | Reference |
|---|---|---|---|
| Des(Gly1)contryphan-R | COwEPWC-NH2 | C. radiatus | [4] |
| Contryphan-R | GCOwEPWC-NH2 | Conus radiatus | [4] |
| Bromocontyphan-R | GCOwEPXC-NH2 | C. radiatus | [5] |
| Contryphan-Sm | GCOwQPWC-NH2 | Conus stercusmuscarum | [6] |
| Contryphan-P | GCOwDPWC-NH2 | C. purpurascens | [6] |
| Contryphan-R/Tx | GCOwEPWC-NH2 | Conus textile | [6] |
| Contryphan-Tx | GCOWQPYC-NH2 | Conus textile | [6] |
| Contryphan-Vn | GDCPwKPWC-NH2 | Conus ventricosus | [7] |
| Leu-contryphan-P | GCVlLPWC-OH | Conus purpurascens | [8] |
| Leu-contryphan-Tx | CVlYPWC-NH2 | Conus textile | [6] |
| Glaconryphan-M | NγSγCPWHPWC-NH2 | Conus marmoreus | [2] |
where the
sequence
abbreviations stand for:
- O = 4-trans-hydroxyproline,
- l = D-leucine, L = L-leucine,
- w = D-tryptophan, W = L-tryptophan,
- γ = gamma-carboxyglutamic acid,
- NH2 = C-terminal amidation
and the remainder of the letters refer to the standard one letter abbreviations for amino acids.
Mechanism of toxicity
The venom of cone snails cause paralysis of their fish prey. The molecular target has not been determined for all contryphan peptides, however it is known that contryphan-Vn is a Ca2+-dependent K+ channel modulator,[7] while glacontryphan-M is a L-type calcium channel blocker.[2]
References
External links
- Contryphan at the U.S. National Library of Medicine Medical Subject Headings (MeSH)