View source for 1qk6


==Solution structure of huwentoxin-I by NMR==
<StructureSection load='1qk6' size='340' side='right'caption='[[1qk6]]' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[1qk6]] is a 1 chain structure with sequence from [https://en.wikipedia.org/wiki/Cyriopagopus_schmidti Cyriopagopus schmidti]. Full experimental information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1QK6 OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=1QK6 FirstGlance]. <br>
</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=1qk6 FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=1qk6 OCA], [https://pdbe.org/1qk6 PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=1qk6 RCSB], [https://www.ebi.ac.uk/pdbsum/1qk6 PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=1qk6 ProSAT]</span></td></tr>
</table>
== Function ==
[https://www.uniprot.org/uniprot/TXH1_CYRSC TXH1_CYRSC] Lethal toxin with multiple biological activities. Inhibits voltage-gated TTX-sensitive sodium channels in DRG neurons (IC(50)=55 nM) and also shows activity when directly tested on Nav1.7/SCN9A (IC(50)=25.1-630 nM) (PubMed:17451655, PubMed:21731778, PubMed:31234412). Inhibits N-type calcium channels (Cav2.2/CACNA1B (IC(50)=100 nM)) (PubMed:11024489, PubMed:17451655). Also blocks neuromuscular transmission (PubMed:10736477, PubMed:8212049, PubMed:9028007). In vivo, intrathecal injected toxin shows analgesic activity in the rat formalin-induced pain model, without induction of motor dysfunction in rats.<ref>PMID:15581678</ref> 
<div style="background-color:#fffaf0;">
== Publication Abstract from PubMed ==
The three-dimensional structure in aqueous solution of native huwentoxin-I, a neurotoxin from the venom of the spider Selenocosmia huwena, has been determined from two-dimensional H NMR data recorded at 500 and 600 MHz. Structural constraints consisting of interproton distances inferred from NOEs and dihedral angles from spin-spin coupling constants were used as input for distance geometry calculation with the program XPLOR 3.1. The best 10 structures have NOE violations &lt; 0.3 A, dihedral violations &lt; 2 degrees, and pairwise root-mean-square differences of 1.08 (+/- 0.20) A over backbone atoms (N, C alpha, C). The molecule adopts a compact structure consisting of a small triple-stranded antiparallel beta-sheet and five beta-turns. A small hydrophobic patch consisting of Phe 6, Trp 28, and Trp 31 is located on one side of the molecule. All six lysine residues are distributed on the molecular surface. The three disulfide bridges are buried within the molecule. The structure contains an "inhibitor cystine knot motif" which is adopted by several other small proteins, such as omega-conotoxin, agatoxin IVA, and gurmarin.

Proton nuclear magnetic resonance studies on huwentoxin-I from the venom of the spider Selenocosmia huwena: 2. Three-dimensional structure in solution.,Qu Y, Liang S, Ding J, Liu X, Zhang R, Gu X J Protein Chem. 1997 Aug;16(6):565-74. PMID:9263120<ref>PMID:9263120</ref>

From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>
</div>
<div class="pdbe-citations 1qk6" style="background-color:#fffaf0;"></div>
== References ==
<references/>
__TOC__
</StructureSection>
[[Category: Cyriopagopus schmidti]]
[[Category: Large Structures]]
[[Category: Ding J]]
[[Category: Gu X]]
[[Category: Liang S]]
[[Category: Liu X]]
[[Category: Qu Y]]
[[Category: Zhang R]]