Contryphan
| Contryphan | |||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|
 | |||||||||||
| Identifiers | |||||||||||
| Symbol | Contryphan_CS | ||||||||||
| Pfam | PF02950 | ||||||||||
| InterPro | IPR011062 | ||||||||||
| PROSITE | PS60027 | ||||||||||
| SCOP2 | 2cco / SCOPe / SUPFAM | ||||||||||
| |||||||||||
The contryphans (conus + tryptophan) are a family of peptides that are active constituents of the potent venom produced by cone snail (genus Conus). The two amino acid cysteine residues in contryphans are linked by a disulfide bond. In addition, contryphans undergo an unusual degree of post-translational modification including epimerization of leucine and tryptophan, tryptophan bromination, 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
[edit | edit source]
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
[edit | edit source]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
[edit | edit source]- ^ PDB: 1NXN; Lua error in Module:Citation/CS1/Configuration at line 2172: attempt to index field '?' (a nil value).
- ^ a b c Lua error in Module:Citation/CS1/Configuration at line 2172: attempt to index field '?' (a nil value).
- ^ Lua error in Module:Citation/CS1/Configuration at line 2172: attempt to index field '?' (a nil value).
- ^ a b Lua error in Module:Citation/CS1/Configuration at line 2172: attempt to index field '?' (a nil value).
- ^ Lua error in Module:Citation/CS1/Configuration at line 2172: attempt to index field '?' (a nil value).
- ^ a b c d e Lua error in Module:Citation/CS1/Configuration at line 2172: attempt to index field '?' (a nil value).
- ^ a b Lua error in Module:Citation/CS1/Configuration at line 2172: attempt to index field '?' (a nil value).
- ^ Lua error in Module:Citation/CS1/Configuration at line 2172: attempt to index field '?' (a nil value).
External links
[edit | edit source]- Contryphan at the U.S. National Library of Medicine Medical Subject Headings (MeSH)