View source for 1qfb


==THE CYCLIC PEPTIDE CONTRYPHAN-R FROM CONUS RADIATUS==
<StructureSection load='1qfb' size='340' side='right'caption='[[1qfb]]' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[1qfb]] is a 1 chain structure with sequence from [https://en.wikipedia.org/wiki/Conus_radiatus Conus radiatus]. Full experimental information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1QFB OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=1QFB FirstGlance]. <br>
</td></tr><tr id='method'><td class="sblockLbl"><b>[[Empirical_models|Method:]]</b></td><td class="sblockDat" id="methodDat">Solution NMR</td></tr>
<tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=DTR:D-TRYPTOPHAN'>DTR</scene>, <scene name='pdbligand=HYP:4-HYDROXYPROLINE'>HYP</scene>, <scene name='pdbligand=NH2:AMINO+GROUP'>NH2</scene></td></tr>
<tr id='resources'><td class="sblockLbl"><b>Resources:</b></td><td class="sblockDat"><span class='plainlinks'>[https://proteopedia.org/fgij/fg.htm?mol=1qfb FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=1qfb OCA], [https://pdbe.org/1qfb PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=1qfb RCSB], [https://www.ebi.ac.uk/pdbsum/1qfb PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=1qfb ProSAT]</span></td></tr>
</table>
== Function ==
[https://www.uniprot.org/uniprot/COW_CONRA COW_CONRA] Its target is unknown, but this toxin may modulate voltage-activated calcium channels (Cav) or calcium-dependent potassium channels (KCa).[UniProtKB:P0C248][UniProtKB:P0C250][UniProtKB:P62903][UniProtKB:P83047]
<div style="background-color:#fffaf0;">
== Publication Abstract from PubMed ==
Contryphan-R is a disulfide-constrained octapeptide containing a D-tryptophan that was isolated recently from venom of the cone shell Conus radiatus. The polypeptide is present in two forms in solution due to cis-trans isomerization at hydroxyproline 3. The solution structure of the major form of this unusual polypeptide, determined from NMR data, consists of a well-defined fold containing a non-hydrogen-bonded chain reversal from Gly1 to Glu5, which includes a cis-hydroxyproline and a D-Trp, and a type I beta-turn from Glu5 to Cys8. The presence of a putative salt bridge between the Glu5 carboxyl group and the N-terminal ammonium group is investigated by using various solvation models during energy minimization and is compared with the results of a pH titration. A comparison of the structure of contryphan-R with other cyclic peptide structures highlights some of the key structural determinants of these peptides and suggests that the contryphan-R fold could be exploited as a scaffold onto which unrelated protein binding surfaces could be grafted. Comparison with small disulfide-bridged loops in larger proteins shows that contryphan-R is similar to a commonly occurring loop structure found in proteins.

Solution structure of contryphan-R, a naturally occurring disulfide-bridged octapeptide containing D-tryptophan: comparison with protein loops.,Pallaghy PK, Melnikova AP, Jimenez EC, Olivera BM, Norton RS Biochemistry. 1999 Aug 31;38(35):11553-9. PMID:10471307<ref>PMID:10471307</ref>

From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>
</div>
<div class="pdbe-citations 1qfb" style="background-color:#fffaf0;"></div>
== References ==
<references/>
__TOC__
</StructureSection>
[[Category: Conus radiatus]]
[[Category: Large Structures]]
[[Category: Jimenez EC]]
[[Category: Melnikova AP]]
[[Category: Norton RS]]
[[Category: Olivera BM]]
[[Category: Pallaghy PK]]