1wqe: Difference between revisions
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==An unusual fold for potassium channel blockers: NMR structure of three toxins from the scorpion Opisthacanthus madagascariensis== | ==An unusual fold for potassium channel blockers: NMR structure of three toxins from the scorpion Opisthacanthus madagascariensis== | ||
<StructureSection load='1wqe' size='340' side='right' caption='[[1wqe | <StructureSection load='1wqe' size='340' side='right'caption='[[1wqe]]' scene=''> | ||
== Structural highlights == | == Structural highlights == | ||
<table><tr><td colspan='2'>[[1wqe]] is a 1 chain structure with sequence from [ | <table><tr><td colspan='2'>[[1wqe]] is a 1 chain structure with sequence from [https://en.wikipedia.org/wiki/Opisthacanthus_madagascariensis Opisthacanthus madagascariensis]. Full experimental information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1WQE OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=1WQE FirstGlance]. <br> | ||
</td></tr><tr id=' | </td></tr><tr id='method'><td class="sblockLbl"><b>[[Empirical_models|Method:]]</b></td><td class="sblockDat" id="methodDat">Solution NMR, 30 models</td></tr> | ||
<tr id='resources'><td class="sblockLbl"><b>Resources:</b></td><td class="sblockDat"><span class='plainlinks'>[ | <tr id='resources'><td class="sblockLbl"><b>Resources:</b></td><td class="sblockDat"><span class='plainlinks'>[https://proteopedia.org/fgij/fg.htm?mol=1wqe FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=1wqe OCA], [https://pdbe.org/1wqe PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=1wqe RCSB], [https://www.ebi.ac.uk/pdbsum/1wqe PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=1wqe ProSAT]</span></td></tr> | ||
</table> | </table> | ||
== Function == | |||
[https://www.uniprot.org/uniprot/KKX23_OPIMA KKX23_OPIMA] Decreases the amplitude of the potassium current of the rat channels Kv1.1/KCNA1 by 33% and Kv1.2/KCNA2 by 8% as well as human Kv1.3/KCNA3 by 70%.<ref>PMID:15631621</ref> | |||
<div style="background-color:#fffaf0;"> | <div style="background-color:#fffaf0;"> | ||
== Publication Abstract from PubMed == | == Publication Abstract from PubMed == | ||
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From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.<br> | From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.<br> | ||
</div> | </div> | ||
<div class="pdbe-citations 1wqe" style="background-color:#fffaf0;"></div> | |||
==See Also== | ==See Also== | ||
*[[Potassium channel toxin|Potassium channel toxin]] | *[[Potassium channel toxin 3D structures|Potassium channel toxin 3D structures]] | ||
== References == | == References == | ||
<references/> | <references/> | ||
__TOC__ | __TOC__ | ||
</StructureSection> | </StructureSection> | ||
[[Category: Large Structures]] | |||
[[Category: Opisthacanthus madagascariensis]] | [[Category: Opisthacanthus madagascariensis]] | ||
[[Category: Chagot | [[Category: Chagot B]] | ||
[[Category: Corzo | [[Category: Corzo G]] | ||
[[Category: Dai | [[Category: Dai L]] | ||
[[Category: Darbon | [[Category: Darbon H]] | ||
[[Category: Ferrat | [[Category: Ferrat G]] | ||
[[Category: Nakajima | [[Category: Nakajima T]] | ||
[[Category: Pil | [[Category: Pil J]] | ||
[[Category: Pimentel | [[Category: Pimentel C]] | ||
[[Category: Tytgat | [[Category: Tytgat J]] | ||
Latest revision as of 03:38, 21 November 2024
An unusual fold for potassium channel blockers: NMR structure of three toxins from the scorpion Opisthacanthus madagascariensisAn unusual fold for potassium channel blockers: NMR structure of three toxins from the scorpion Opisthacanthus madagascariensis
Structural highlights
FunctionKKX23_OPIMA Decreases the amplitude of the potassium current of the rat channels Kv1.1/KCNA1 by 33% and Kv1.2/KCNA2 by 8% as well as human Kv1.3/KCNA3 by 70%.[1] Publication Abstract from PubMedThe Om-toxins are short peptides (23-27 amino acids) purified from the venom of the scorpion Opisthacanthus madagascariensis. Their pharmacological targets are thought to be potassium channels. Like Csalpha/beta (cystine-stabilized alpha/beta) toxins, the Om-toxins alter the electrophysiological properties of these channels; however, they do not share any sequence similarity with other scorpion toxins. We herein demonstrate by electrophysiological experiments that Om-toxins decrease the amplitude of the K+ current of the rat channels Kv1.1 and Kv1.2, as well as human Kv1.3. We also determine the solution structure of three of the toxins by use of two-dimensional proton NMR techniques followed by distance geometry and molecular dynamics. The structures of these three peptides display an uncommon fold for ion-channel blockers, Csalpha/alpha (cystine-stabilized alpha-helix-loop-helix), i.e. two alpha-helices connected by a loop and stabilized by two disulphide bridges. We compare the structures obtained and the dipole moments resulting from the electrostatic anisotropy of these peptides with those of the only other toxin known to share the same fold, namely kappa-hefutoxin1. An unusual fold for potassium channel blockers: NMR structure of three toxins from the scorpion Opisthacanthus madagascariensis.,Chagot B, Pimentel C, Dai L, Pil J, Tytgat J, Nakajima T, Corzo G, Darbon H, Ferrat G Biochem J. 2005 May 15;388(Pt 1):263-71. PMID:15631621[2] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See AlsoReferences
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