1n8m: Difference between revisions
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==Solution structure of Pi4, a four disulfide bridged scorpion toxin active on potassium channels== | ==Solution structure of Pi4, a four disulfide bridged scorpion toxin active on potassium channels== | ||
<StructureSection load='1n8m' size='340' side='right' caption='[[1n8m | <StructureSection load='1n8m' size='340' side='right'caption='[[1n8m]]' scene=''> | ||
== Structural highlights == | == Structural highlights == | ||
<table><tr><td colspan='2'>[[1n8m]] is a 1 chain structure. Full experimental information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1N8M OCA]. For a <b>guided tour on the structure components</b> use [ | <table><tr><td colspan='2'>[[1n8m]] is a 1 chain structure with sequence from [https://en.wikipedia.org/wiki/Pandinus_imperator Pandinus imperator]. Full experimental information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1N8M OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=1N8M FirstGlance]. <br> | ||
</td></tr><tr id='resources'><td class="sblockLbl"><b>Resources:</b></td><td class="sblockDat"><span class='plainlinks'>[ | </td></tr><tr id='method'><td class="sblockLbl"><b>[[Empirical_models|Method:]]</b></td><td class="sblockDat" id="methodDat">Solution NMR, 10 models</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=1n8m FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=1n8m OCA], [https://pdbe.org/1n8m PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=1n8m RCSB], [https://www.ebi.ac.uk/pdbsum/1n8m PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=1n8m ProSAT]</span></td></tr> | |||
</table> | </table> | ||
== Function == | == Function == | ||
[ | [https://www.uniprot.org/uniprot/KAX64_PANIM KAX64_PANIM] Potently, completely and reversibly blocks voltage-gated potassium channel Kv1.2/KCNA2 and Shaker B (Sh). Also blocks small conductance (SK) calcium-activated potassium channel (KCNN).<ref>PMID:12919322</ref> | ||
<div style="background-color:#fffaf0;"> | <div style="background-color:#fffaf0;"> | ||
== Publication Abstract from PubMed == | == Publication Abstract from PubMed == | ||
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==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: | [[Category: Large Structures]] | ||
[[Category: Delepierre | [[Category: Pandinus imperator]] | ||
[[Category: Garnier | [[Category: Delepierre M]] | ||
[[Category: Gomez-Lagunas | [[Category: Garnier D]] | ||
[[Category: Guijarro | [[Category: Gomez-Lagunas F]] | ||
[[Category: Olamendi-Portugal | [[Category: Guijarro JI]] | ||
[[Category: Possani | [[Category: M'Barek S]] | ||
[[Category: Rochat | [[Category: Olamendi-Portugal T]] | ||
[[Category: Sabatier | [[Category: Possani LD]] | ||
[[Category: Rochat H]] | |||
[[Category: Sabatier JM]] | |||
Latest revision as of 11:39, 6 November 2024
Solution structure of Pi4, a four disulfide bridged scorpion toxin active on potassium channelsSolution structure of Pi4, a four disulfide bridged scorpion toxin active on potassium channels
Structural highlights
FunctionKAX64_PANIM Potently, completely and reversibly blocks voltage-gated potassium channel Kv1.2/KCNA2 and Shaker B (Sh). Also blocks small conductance (SK) calcium-activated potassium channel (KCNN).[1] Publication Abstract from PubMedPi4 is a short toxin found at very low abundance in the venom of Pandinus imperator scorpions. It is a potent blocker of K(+) channels. Like the other members of the alpha-KTX6 subfamily to which it belongs, it is cross-linked by four disulfide bonds. The synthetic analog (sPi4) and the natural toxin (nPi4) have been obtained by solid-phase synthesis or from scorpion venom, respectively. Analysis of two-dimensional (1)H NMR spectra of nPi4 and sPi4 indicates that both peptides have the same structure. Moreover, electrophysiological recordings of the blocking of Shaker B K(+) channels by sPi4 (K(D) = 8.5 nM) indicate that sPi4 has the same blocking activity of nPi4 (K(D) = 8.0 nM), previously described. The disulfide bonds have been independently determined by NMR and structure calculations, and by Edman-degradation/mass-spectrometry identification of peptides obtained by proteolysis of nPi4. Both approaches indicate that the pairing of the half-cystines is (6)C-(27)C, (12)C-(32)C, (16)C-(34)C, and (22)C-(37)C. The structure of the toxin has been determined by using 705 constraints derived from NMR data on sPi4. The structure, which is well defined, shows the characteristic alpha/beta scaffold of scorpion toxins. It is compared to the structure of the other alpha-KTX6 subfamily members and, in particular, to the structure of maurotoxin, which shows a different pattern of disulfide bridges despite its high degree of sequence identity (76%) with Pi4. The structure of Pi4 and the high amounts of synthetic peptide available, will enable the detailed analysis of the interaction of Pi4 with K(+) channels. Solution structure of Pi4, a short four-disulfide-bridged scorpion toxin specific of potassium channels.,Guijarro JI, M'Barek S, Gomez-Lagunas F, Garnier D, Rochat H, Sabatier JM, Possani L, Delepierre M Protein Sci. 2003 Sep;12(9):1844-54. PMID:12930984[2] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See AlsoReferences
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