Contryphan

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Contryphan
1NXN.png
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
Symbol Contryphan_CS
Pfam PF02950
InterPro IPR011062
PROSITE PS60027
SCOP 2cco
SUPERFAMILY 2cco

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]

Family members[edit]

Conus textile, which produces contryphans

Contryphan family members include:

Peptide Sequence Species Reference
Des(Gly1)contryphan-R COwEPWC-NH2 C. radiatus [3]
Contryphan-R GCOwEPWC-NH2 Conus radiatus [3]
Bromocontyphan-R GCOwEPXC-NH2 C. radiatus [4]
Contryphan-Sm GCOwQPWC-NH2 Conus stercusmuscarum [5]
Contryphan-P GCOwDPWC-NH2 C. purpurascens [5]
Contryphan-R/Tx GCOwEPWC-NH2 Conus textile [5]
Contryphan-Tx GCOWQPYC-NH2 Conus textile [5]
Contryphan-Vn GDCPwKPWC-NH2 Conus ventricosus [6]
Leu-contryphan-P GCVlLPWC-OH Conus purpurascens [7]
Leu-contryphan-Tx CVlYPWC-NH2 Conus textile [5]
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,[6] while glacontryphan-M is a L-type calcium channel blocker.[2]

See also[edit]

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. 
  2. ^ a b c Hansson K, Ma X, Eliasson L, Czerwiec E, Furie B, Furie BC, Rorsman P, Stenflo J (2004). "The first gamma-carboxyglutamic acid-containing contryphan. A selective L-type calcium ion channel blocker isolated from the venom of Conus marmoreus". J. Biol. Chem. 279 (31): 32453–63. doi:10.1074/jbc.M313825200. PMID 15155730. 
  3. ^ a b Jimenéz EC, Olivera BM, Gray WR, Cruz LJ (1996). "Contryphan is a D-tryptophan-containing Conus peptide". J. Biol. Chem. 271 (45): 28002–5. doi:10.1074/jbc.271.45.28002. PMID 8910408. 
  4. ^ Jimenez EC, Craig AG, Watkins M, Hillyard DR, Gray WR, Gulyas J, Rivier JE, Cruz LJ, Olivera BM (1997). "Bromocontryphan: post-translational bromination of tryptophan". Biochemistry. 36 (5): 989–94. doi:10.1021/bi962840p. PMID 9033387. 
  5. ^ a b c d e Jacobsen R, Jimenez EC, Grilley M, Watkins M, Hillyard D, Cruz LJ, Olivera BM (1998). "The contryphans, a D-tryptophan-containing family of Conus peptides: interconversion between conformers". J. Pept. Res. 51 (3): 173–9. doi:10.1111/j.1399-3011.1998.tb01213.x. PMID 9531419. 
  6. ^ a b Massilia GR, Schininà ME, Ascenzi P, Polticelli F (2001). "Contryphan-Vn: a novel peptide from the venom of the Mediterranean snail Conus ventricosus". Biochem. Biophys. Res. Commun. 288 (4): 908–13. doi:10.1006/bbrc.2001.5833. PMID 11688995. 
  7. ^ Jacobsen RB, Jimenez EC, De la Cruz RG, Gray WR, Cruz LJ, Olivera BM (1999). "A novel D-leucine-containing Conus peptide: diverse conformational dynamics in the contryphan family". J. Pept. Res. 54 (2): 93–9. doi:10.1034/j.1399-3011.1999.00093.x. PMID 10461743. 

External links[edit]