Contryphan

{{Pfam_box | Symbol = Contryphan_CS | Name = Contryphan | image = 1NXN.png | width = | caption = NMR structure of Contryphan-Vn. The peptide backbone is depicted by a curved tube while the amino acid side-chains are represented by capped sticks. Carbon atoms are colored grey, nitrogen atoms blue, oxygen atoms red, and sulfur atoms yellow.<ref name="pmid15150794">{{PDB|1NXN}}; {{cite journal | vauthors = Eliseo T, Cicero DO, Romeo C, Schininà ME, Massilia GR, Polticelli F, Ascenzi P, Paci M | title = Solution structure of the cyclic peptide contryphan-Vn, a Ca2+-dependent K+ channel modulator | journal = Biopolymers | volume = 74 | issue = 3 | pages = 189–98 | date = June 2004 | pmid = 15150794 | doi = 10.1002/bip.20025 | s2cid = 24487744 }}</ref> . | Pfam = PF02950 | InterPro = IPR011062 | SMART = | PROSITE = PS60027 | SCOP = 2cco | TCDB = | OPM family = | OPM protein = | PDB = {{PDB2|1dfy }}, {{PDB2|1dfz}} , {{PDB2|1dg0}} , {{PDB2|1nxn}} , {{PDB2|1qfb}} }}

The '''contryphan'''s ('''con'''us + '''try'''pto'''phan''') 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.<ref name="pmid15155730">{{cite journal | vauthors = Hansson K, Ma X, Eliasson L, Czerwiec E, Furie B, Furie BC, Rorsman P, Stenflo J | title = The first gamma-carboxyglutamic acid-containing contryphan. A selective L-type calcium ion channel blocker isolated from the venom of Conus marmoreus | journal = The Journal of Biological Chemistry | volume = 279 | issue = 31 | pages = 32453–63 | date = July 2004 | pmid = 15155730 | doi = 10.1074/jbc.M313825200 | doi-access = free }}</ref> In the broader scheme of genetic conotoxin classification, contryphans are members of "Conotoxin Superfamily O2."<ref>{{cite journal | vauthors = Robinson SD, Norton RS | title = Conotoxin gene superfamilies | journal = Marine Drugs | volume = 12 | issue = 12 | pages = 6058–101 | date = December 2014 | pmid = 25522317 | pmc = 4278219 | doi = 10.3390/md12126058 | doi-access = free }}</ref>

==Family members== [[Image:Textile cone.JPG|thumb|right|238px|''Conus textile'', which produces '''contryphans''']]

Contryphan family members include: {| class="wikitable" |- ! Peptide ! Sequence ! Species ! Reference |- | Des(Gly1)contryphan-R | COwEPWC-NH2 | ''C. radiatus'' | <ref name="pmid8910408">{{cite journal | vauthors = Jimenéz EC, Olivera BM, Gray WR, Cruz LJ | title = Contryphan is a D-tryptophan-containing Conus peptide | journal = The Journal of Biological Chemistry | volume = 271 | issue = 45 | pages = 28002–5 | date = November 1996 | pmid = 8910408 | doi = 10.1074/jbc.271.45.28002 | doi-access = free }}</ref> |- | Contryphan-R | GCOwEPWC-NH2 | ''Conus radiatus'' | <ref name="pmid8910408" /> |- | Bromocontyphan-R | GCOwEPXC-NH2 | ''C. radiatus'' | <ref name="pmid9033387">{{cite journal | vauthors = Jimenez EC, Craig AG, Watkins M, Hillyard DR, Gray WR, Gulyas J, Rivier JE, Cruz LJ, Olivera BM | title = Bromocontryphan: post-translational bromination of tryptophan | journal = Biochemistry | volume = 36 | issue = 5 | pages = 989–94 | date = February 1997 | pmid = 9033387 | doi = 10.1021/bi962840p }}</ref> |- | Contryphan-Sm | GCOwQPWC-NH2 | ''Conus stercusmuscarum'' | <ref name="pmid9531419">{{cite journal | vauthors = Jacobsen R, Jimenez EC, Grilley M, Watkins M, Hillyard D, Cruz LJ, Olivera BM | title = The contryphans, a D-tryptophan-containing family of Conus peptides: interconversion between conformers | journal = The Journal of Peptide Research | volume = 51 | issue = 3 | pages = 173–9 | date = March 1998 | pmid = 9531419 | doi = 10.1111/j.1399-3011.1998.tb01213.x }}</ref> |- | Contryphan-P | GCOwDPWC-NH2 | ''C. purpurascens'' | <ref name="pmid9531419" /> |- | Contryphan-R/Tx | GCOwEPWC-NH2 | ''Conus textile'' | <ref name="pmid9531419" /> |- | Contryphan-Tx | GCOWQPYC-NH2 | ''Conus textile'' | <ref name="pmid9531419" /> |- | Contryphan-Vn | GDCPwKPWC-NH2 | ''Conus ventricosus'' | <ref name="pmid11688995">{{cite journal | vauthors = Massilia GR, Schininà ME, Ascenzi P, Polticelli F | title = Contryphan-Vn: a novel peptide from the venom of the Mediterranean snail Conus ventricosus | journal = Biochemical and Biophysical Research Communications | volume = 288 | issue = 4 | pages = 908–13 | date = November 2001 | pmid = 11688995 | doi = 10.1006/bbrc.2001.5833 | bibcode = 2001BBRC..288..908M }}</ref> |- | Leu-contryphan-P | GCVlLPWC-OH | ''Conus purpurascens'' | <ref name="pmid10461743">{{cite journal | vauthors = Jacobsen RB, Jimenez EC, De la Cruz RG, Gray WR, Cruz LJ, Olivera BM | title = A novel D-leucine-containing Conus peptide: diverse conformational dynamics in the contryphan family | journal = The Journal of Peptide Research | volume = 54 | issue = 2 | pages = 93–9 | date = August 1999 | pmid = 10461743 | doi = 10.1034/j.1399-3011.1999.00093.x }}</ref> |- | Leu-contryphan-Tx | CVlYPWC-NH2 | ''Conus textile'' | <ref name="pmid9531419" /> |- | Glaconryphan-M | NγSγCPWHPWC-NH2 | ''Conus marmoreus'' | <ref name="pmid15155730" /> |} 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,<ref name="pmid11688995" /> while glacontryphan-M is a L-type calcium channel blocker.<ref name="pmid15155730" />

== References == {{Reflist|2}}

== External links == * {{MeshName|Contryphan}}

Category:Neurotoxins Category:Ion channel toxins Category:Snail toxins