Contryphan

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Contryphan
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.[1]
.
Identifiers
SymbolContryphan_CS
PfamPF02950
InterProIPR011062
PROSITEPS60027
SCOP22cco / SCOPe / SUPFAM
Available protein structures:
Pfam  structures / ECOD  
PDBRCSB PDB; PDBe; PDBj
PDBsumstructure summary
PDB1dfy ​, 1dfz​ , 1dg0​ , 1nxn​ , 1qfb​

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]

Conus textile, which produces contryphans

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:

and the remainder of the letters refer to the standard one letter abbreviations for amino acids.

Mechanism of toxicity[edit]

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]

  1. ^ PDB: 1NXN​; Eliseo T, Cicero DO, Romeo C, Schininà ME, Massilia GR, Polticelli F, Ascenzi P, Paci M (June 2004). "Solution structure of the cyclic peptide contryphan-Vn, a Ca2+-dependent K+ channel modulator". Biopolymers. 74 (3): 189–98. doi:10.1002/bip.20025. PMID 15150794. S2CID 24487744.
  2. ^ a b c Hansson K, Ma X, Eliasson L, Czerwiec E, Furie B, Furie BC, Rorsman P, Stenflo J (July 2004). "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. doi:10.1074/jbc.M313825200. PMID 15155730.
  3. ^ Robinson SD, Norton RS (December 2014). "Conotoxin gene superfamilies". Marine Drugs. 12 (12): 6058–101. doi:10.3390/md12126058. PMC 4278219. PMID 25522317.
  4. ^ a b Jimenéz EC, Olivera BM, Gray WR, Cruz LJ (November 1996). "Contryphan is a D-tryptophan-containing Conus peptide". The Journal of Biological Chemistry. 271 (45): 28002–5. doi:10.1074/jbc.271.45.28002. PMID 8910408.
  5. ^ Jimenez EC, Craig AG, Watkins M, Hillyard DR, Gray WR, Gulyas J, Rivier JE, Cruz LJ, Olivera BM (February 1997). "Bromocontryphan: post-translational bromination of tryptophan". Biochemistry. 36 (5): 989–94. doi:10.1021/bi962840p. PMID 9033387.
  6. ^ a b c d e Jacobsen R, Jimenez EC, Grilley M, Watkins M, Hillyard D, Cruz LJ, Olivera BM (March 1998). "The contryphans, a D-tryptophan-containing family of Conus peptides: interconversion between conformers". The Journal of Peptide Research. 51 (3): 173–9. doi:10.1111/j.1399-3011.1998.tb01213.x. PMID 9531419.
  7. ^ a b Massilia GR, Schininà ME, Ascenzi P, Polticelli F (November 2001). "Contryphan-Vn: a novel peptide from the venom of the Mediterranean snail Conus ventricosus". Biochemical and Biophysical Research Communications. 288 (4): 908–13. doi:10.1006/bbrc.2001.5833. PMID 11688995.
  8. ^ Jacobsen RB, Jimenez EC, De la Cruz RG, Gray WR, Cruz LJ, Olivera BM (August 1999). "A novel D-leucine-containing Conus peptide: diverse conformational dynamics in the contryphan family". The Journal of Peptide Research. 54 (2): 93–9. doi:10.1034/j.1399-3011.1999.00093.x. PMID 10461743.

External links[edit]

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