View source for 1kcp


==3D STRUCTURE OF K-CONOTOXIN PVIIA, A NOVEL POTASSIUM CHANNEL-BLOCKING TOXIN FROM CONE SNAILS, NMR, 22 STRUCTURES==
<StructureSection load='1kcp' size='340' side='right'caption='[[1kcp]]' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[1kcp]] is a 1 chain structure with sequence from [https://en.wikipedia.org/wiki/Conus_purpurascens Conus purpurascens]. Full experimental information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1KCP OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=1KCP FirstGlance]. <br>
</td></tr><tr id='method'><td class="sblockLbl"><b>[[Empirical_models|Method:]]</b></td><td class="sblockDat" id="methodDat">Solution NMR, 22 models</td></tr>
<tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><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=1kcp FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=1kcp OCA], [https://pdbe.org/1kcp PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=1kcp RCSB], [https://www.ebi.ac.uk/pdbsum/1kcp PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=1kcp ProSAT]</span></td></tr>
</table>
== Function ==
[https://www.uniprot.org/uniprot/O17A_CONPU O17A_CONPU] Kappa-conotoxins bind and inhibit voltage-gated potassium channels (Kv). This toxin inhibits the drosophila Shaker channel (IC(50)=57-80 nM) (PubMed:12074021, PubMed:10818087, PubMed:27093300). In vivo, when tested in fish, this toxin induces hyperactivity, followed by continuous contraction and extension of major fins, without immobilization or death (PubMed:9417043, PubMed:12074021). Injection of this peptide together with the delta-conotoxin PVIA causes the sudden tetanus of prey (STOP) syndrome, which is a single, lethal 'fin-pop' in envenomed fish (PubMed:9417043, PubMed:12074021). When tested in mice, induces hyperactivity (PubMed:9417043).<ref>PMID:10398696</ref> <ref>PMID:10818087</ref> <ref>PMID:12023223</ref> <ref>PMID:12074021</ref> <ref>PMID:27093300</ref> <ref>PMID:9417043</ref> 
<div style="background-color:#fffaf0;">
== Publication Abstract from PubMed ==
kappa-Conotoxin PVIIA from the venom of Conus purpurascens is the first cone snail toxin that was described to block potassium channels. We synthesized chemically this toxin and showed that its disulfide bridge pattern is similar to those of omega- and delta-conotoxins. kappa-conotoxin competes with radioactive alpha-dendrotoxin for binding to rat brain synaptosomes, confirming its capacity to bind to potassium channels; however, it behaves as a weak competitor. The three-dimensional structure of kappa-conotoxin PVIIA, as elucidated by NMR spectroscopy and molecular modeling, comprises two large parallel loops stabilized by a triple-stranded antiparallel beta-sheet and three disulfide bridges. The overall fold of kappa-conotoxin is similar to that of calcium channel-blocking omega-conotoxins but differs from those of potassium channel-blocking toxins from sea anemones, scorpions, and snakes. Local topographies of kappa-conotoxin PVIIA that might account for its capacity to recognize Kv1-type potassium channels are discussed.

Three-dimensional structure of kappa-conotoxin PVIIA, a novel potassium channel-blocking toxin from cone snails.,Savarin P, Guenneugues M, Gilquin B, Lamthanh H, Gasparini S, Zinn-Justin S, Menez A Biochemistry. 1998 Apr 21;37(16):5407-16. PMID:9548922<ref>PMID:9548922</ref>

From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>
</div>
<div class="pdbe-citations 1kcp" style="background-color:#fffaf0;"></div>
== References ==
<references/>
__TOC__
</StructureSection>
[[Category: Conus purpurascens]]
[[Category: Large Structures]]
[[Category: Gasparini S]]
[[Category: Gilquin B]]
[[Category: Guenneugues M]]
[[Category: Lamthanh H]]
[[Category: Menez A]]
[[Category: Savarin P]]
[[Category: Zinn-Justin S]]