Contryphan Explained

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.[1] In the broader scheme of genetic conotoxin classification, contryphans are members of "Conotoxin Superfamily O2."[2]

Family members

Contryphan family members include:

PeptideSequenceSpeciesReference
Des(Gly1)contryphan-RCOwEPWC-NH2C. radiatus[3]
Contryphan-RGCOwEPWC-NH2Conus radiatus
Bromocontyphan-RGCOwEPXC-NH2C. radiatus[4]
Contryphan-SmGCOwQPWC-NH2Conus stercusmuscarum[5]
Contryphan-PGCOwDPWC-NH2C. purpurascens
Contryphan-R/TxGCOwEPWC-NH2Conus textile
Contryphan-TxGCOWQPYC-NH2Conus textile
Contryphan-VnGDCPwKPWC-NH2Conus ventricosus[6]
Leu-contryphan-PGCVlLPWC-OHConus purpurascens[7]
Leu-contryphan-TxCVlYPWC-NH2Conus textile
Glaconryphan-MNγSγCPWHPWC-NH2Conus marmoreus
where the sequence abbreviations stand for:

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, while glacontryphan-M is a L-type calcium channel blocker.

Notes and References

  1. Hansson K, Ma X, Eliasson L, Czerwiec E, Furie B, Furie BC, Rorsman P, Stenflo J . The first gamma-carboxyglutamic acid-containing contryphan. A selective L-type calcium ion channel blocker isolated from the venom of Conus marmoreus . The Journal of Biological Chemistry . 279 . 31 . 32453–63 . July 2004 . 15155730 . 10.1074/jbc.M313825200 . free .
  2. Robinson SD, Norton RS . Conotoxin gene superfamilies . Marine Drugs . 12 . 12 . 6058–101 . December 2014 . 25522317 . 4278219 . 10.3390/md12126058 . free .
  3. Jimenéz EC, Olivera BM, Gray WR, Cruz LJ . Contryphan is a D-tryptophan-containing Conus peptide . The Journal of Biological Chemistry . 271 . 45 . 28002–5 . November 1996 . 8910408 . 10.1074/jbc.271.45.28002 . free .
  4. Jimenez EC, Craig AG, Watkins M, Hillyard DR, Gray WR, Gulyas J, Rivier JE, Cruz LJ, Olivera BM . Bromocontryphan: post-translational bromination of tryptophan . Biochemistry . 36 . 5 . 989–94 . February 1997 . 9033387 . 10.1021/bi962840p .
  5. Jacobsen R, Jimenez EC, Grilley M, Watkins M, Hillyard D, Cruz LJ, Olivera BM . The contryphans, a D-tryptophan-containing family of Conus peptides: interconversion between conformers . The Journal of Peptide Research . 51 . 3 . 173–9 . March 1998 . 9531419 . 10.1111/j.1399-3011.1998.tb01213.x .
  6. Massilia GR, Schininà ME, Ascenzi P, Polticelli F . Contryphan-Vn: a novel peptide from the venom of the Mediterranean snail Conus ventricosus . Biochemical and Biophysical Research Communications . 288 . 4 . 908–13 . November 2001 . 11688995 . 10.1006/bbrc.2001.5833 .
  7. Jacobsen RB, Jimenez EC, De la Cruz RG, Gray WR, Cruz LJ, Olivera BM . A novel D-leucine-containing Conus peptide: diverse conformational dynamics in the contryphan family . The Journal of Peptide Research . 54 . 2 . 93–9 . August 1999 . 10461743 . 10.1034/j.1399-3011.1999.00093.x .

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