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| | ==SOLUTION STRUCTURE OF A TOXIN FROM THE SCORPION TITYUS SERRULATUS (TSTX-K ALPHA) DETERMINED BY NMR.== | | ==SOLUTION STRUCTURE OF A TOXIN FROM THE SCORPION TITYUS SERRULATUS (TSTX-K ALPHA) DETERMINED BY NMR.== |
| - | <StructureSection load='1hp2' size='340' side='right'caption='[[1hp2]], [[NMR_Ensembles_of_Models | 30 NMR models]]' scene=''> | + | <StructureSection load='1hp2' size='340' side='right'caption='[[1hp2]]' scene=''> |
| | == Structural highlights == | | == Structural highlights == |
| - | <table><tr><td colspan='2'>[[1hp2]] is a 1 chain structure with sequence from [https://en.wikipedia.org/wiki/Brazilian_scorpion Brazilian scorpion]. Full experimental information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1HP2 OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=1HP2 FirstGlance]. <br> | + | <table><tr><td colspan='2'>[[1hp2]] is a 1 chain structure with sequence from [https://en.wikipedia.org/wiki/Tityus_serrulatus Tityus serrulatus]. Full experimental information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1HP2 OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=1HP2 FirstGlance]. <br> |
| - | </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=1hp2 FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=1hp2 OCA], [https://pdbe.org/1hp2 PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=1hp2 RCSB], [https://www.ebi.ac.uk/pdbsum/1hp2 PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=1hp2 ProSAT]</span></td></tr> | + | </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='resources'><td class="sblockLbl"><b>Resources:</b></td><td class="sblockDat"><span class='plainlinks'>[https://proteopedia.org/fgij/fg.htm?mol=1hp2 FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=1hp2 OCA], [https://pdbe.org/1hp2 PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=1hp2 RCSB], [https://www.ebi.ac.uk/pdbsum/1hp2 PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=1hp2 ProSAT]</span></td></tr> |
| | </table> | | </table> |
| | == Function == | | == Function == |
| - | [[https://www.uniprot.org/uniprot/KAX41_TITSE KAX41_TITSE]] Potently blocks Kv1.1/KCNA1 (85%), Kv1.2/KCNA2 (91%), Kv1.3/KCNA3 (89%), Kv1.6/KCNA6 (94%), and Shaker (97%).<ref>PMID:12871837</ref> <ref>PMID:24590385</ref> <ref>PMID:7509073</ref>
| + | [https://www.uniprot.org/uniprot/KAX41_TITSE KAX41_TITSE] Potently blocks Kv1.1/KCNA1 (85%), Kv1.2/KCNA2 (91%), Kv1.3/KCNA3 (89%), Kv1.6/KCNA6 (94%), and Shaker (97%).<ref>PMID:12871837</ref> <ref>PMID:24590385</ref> <ref>PMID:7509073</ref> |
| | <div style="background-color:#fffaf0;"> | | <div style="background-color:#fffaf0;"> |
| | == Publication Abstract from PubMed == | | == Publication Abstract from PubMed == |
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| | __TOC__ | | __TOC__ |
| | </StructureSection> | | </StructureSection> |
| - | [[Category: Brazilian scorpion]] | |
| | [[Category: Large Structures]] | | [[Category: Large Structures]] |
| - | [[Category: Blaustein, M P]] | + | [[Category: Tityus serrulatus]] |
| - | [[Category: Ellis, K C]] | + | [[Category: Blaustein MP]] |
| - | [[Category: Gilly, W F]] | + | [[Category: Ellis KC]] |
| - | [[Category: Tenenholz, T C]] | + | [[Category: Gilly WF]] |
| - | [[Category: Weber, D J]] | + | [[Category: Tenenholz TC]] |
| - | [[Category: Alpha-k toxin]] | + | [[Category: Weber DJ]] |
| - | [[Category: K+ channel]]
| + | |
| - | [[Category: Scorpion toxin]]
| + | |
| - | [[Category: Toxin]]
| + | |
| Structural highlights
Function
KAX41_TITSE Potently blocks Kv1.1/KCNA1 (85%), Kv1.2/KCNA2 (91%), Kv1.3/KCNA3 (89%), Kv1.6/KCNA6 (94%), and Shaker (97%).[1] [2] [3]
Publication Abstract from PubMed
A toxin from the scorpion Tityus serrulatus (TsTX-Kalpha) blocks native squid K(+) channels and their cloned counterpart, sqKv1A, at pH 8 ((native)K(d) approximately 20 nM; (sqKv1A)K(d) approximately 10 nM). In both cases, decreasing the pH below 7.0 significantly diminishes the TsTX-Kalpha effect (pK = 6.6). In the cloned squid channel, the pH dependence of the block is abolished by a single point mutation (H351G), and no change in toxin affinity was observed at higher pH values (pH > or =8.0). To further investigate the TsTX-Kalpha-sqKv1A interaction, the three-dimensional structure of TsTX-Kalpha was determined in solution by NMR spectroscopy, and a model of the TsTX-Kalpha-sqKv1A complex was generated. As found for other alpha-K toxins such as charybdotoxin (CTX), site-directed mutagenesis at toxin residue K27 (K27A, K27R, and K27E) significantly reduced the toxin's affinity for sqKv1A channels. This is consistent with the TsTX-Kalpha-sqKv1A model reported here, which has K27 of the toxin inserted into the ion conduction pathway of the K(+) channel. This toxin-channel model also illustrates a possible mechanism for the pH-dependent block whereby lysine residues from TsTX-Kalpha (K6 and K23) are repelled by protonated H351 on sqKv1A at low pH.
Interaction of a toxin from the scorpion Tityus serrulatus with a cloned K+ channel from squid (sqKv1A).,Ellis KC, Tenenholz TC, Jerng H, Hayhurst M, Dudlak CS, Gilly WF, Blaustein MP, Weber DJ Biochemistry. 2001 May 22;40(20):5942-53. PMID:11352729[4]
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.
See Also
References
- ↑ Rodrigues AR, Arantes EC, Monje F, Stuhmer W, Varanda WA. Tityustoxin-K(alpha) blockade of the voltage-gated potassium channel Kv1.3. Br J Pharmacol. 2003 Jul;139(6):1180-6. PMID:12871837 doi:http://dx.doi.org/10.1038/sj.bjp.0705343
- ↑ Cerni FA, Pucca MB, Peigneur S, Cremonez CM, Bordon KC, Tytgat J, Arantes EC. Electrophysiological characterization of Ts6 and Ts7, K(+) channel toxins isolated through an improved Tityus serrulatus venom purification procedure. Toxins (Basel). 2014 Feb 28;6(3):892-913. doi: 10.3390/toxins6030892. PMID:24590385 doi:http://dx.doi.org/10.3390/toxins6030892
- ↑ Rogowski RS, Krueger BK, Collins JH, Blaustein MP. Tityustoxin K alpha blocks voltage-gated noninactivating K+ channels and unblocks inactivating K+ channels blocked by alpha-dendrotoxin in synaptosomes. Proc Natl Acad Sci U S A. 1994 Feb 15;91(4):1475-9. PMID:7509073
- ↑ Ellis KC, Tenenholz TC, Jerng H, Hayhurst M, Dudlak CS, Gilly WF, Blaustein MP, Weber DJ. Interaction of a toxin from the scorpion Tityus serrulatus with a cloned K+ channel from squid (sqKv1A). Biochemistry. 2001 May 22;40(20):5942-53. PMID:11352729
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