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[[Image:1emx.jpg|left|200px]]<br /><applet load="1emx" size="350" color="white" frame="true" align="right" spinBox="true"
caption="1emx" />
'''SOLUTION STRUCTURE OF HPTX2, A TOXIN FROM HETEROPODA VENATORIA SPIDER VENOM THAT BLOCKS KV4.2 POTASSIUM CHANNEL'''<br />


==Overview==
==SOLUTION STRUCTURE OF HPTX2, A TOXIN FROM HETEROPODA VENATORIA SPIDER VENOM THAT BLOCKS KV4.2 POTASSIUM CHANNEL==
<StructureSection load='1emx' size='340' side='right'caption='[[1emx]]' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[1emx]] is a 1 chain structure with sequence from [https://en.wikipedia.org/wiki/Heteropoda_venatoria Heteropoda venatoria]. Full experimental information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1EMX OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=1EMX FirstGlance]. <br>
</td></tr><tr id='method'><td class="sblockLbl"><b>[[Empirical_models|Method:]]</b></td><td class="sblockDat" id="methodDat">Solution NMR, 26 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=1emx FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=1emx OCA], [https://pdbe.org/1emx PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=1emx RCSB], [https://www.ebi.ac.uk/pdbsum/1emx PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=1emx ProSAT]</span></td></tr>
</table>
== Function ==
[https://www.uniprot.org/uniprot/TXHP2_HETVE TXHP2_HETVE] Inhibitor of voltage-gated potassium channels of the Kv4/KCND family. Inhibition of Kv4.3/KCND3 and Kv4.2/KCND2 is strongly voltage-dependent, while inhibition of Kv4.1/KCND1 shows less voltage-dependence. Its binding site may be near the potassium channel voltage sensor. Also blocks calcium channels.<ref>PMID:9058605</ref> [REFERENCE:2]<ref>PMID:15733564</ref>
<div style="background-color:#fffaf0;">
== Publication Abstract from PubMed ==
HpTX2 is a toxin from the venom of Heteropoda venatoria spider that has been demonstrated to bind on Kv4.2 potassium channel. We have determined the solution structure of recombinant HpTX2 by use of conventional two-dimensional NMR techniques followed by distance-geometry and molecular dynamics. The calculated structure belongs to the Inhibitory Cystin Knot structural family that consists in a compact disulfide-bonded core, from which four loops emerge. A poorly defined two-stranded antiparallel beta-sheet (residues 20-23 and 25-28) is detected. Analysis of the electrostatic charge anisotropy allows us to propose a functional map of HpTX2 different from the one described for kappa-conotoxin PVIIA, but strongly related to the one of charybdotoxin. The orientation of the dipole moment of HpTX2 emerges through K27 which could therefore be the critical lysine residue. Close to this lysine are a second basic residue, R23, an aromatic cluster (F7, W25, W30) and an hydrophobic side chain (L24). The high density in aromatic side chains of the putative functional surface as well as the lack of an asparagine is proposed to be the structural basis of the specificity of HpTX2 toward Kv4.2 channel.
HpTX2 is a toxin from the venom of Heteropoda venatoria spider that has been demonstrated to bind on Kv4.2 potassium channel. We have determined the solution structure of recombinant HpTX2 by use of conventional two-dimensional NMR techniques followed by distance-geometry and molecular dynamics. The calculated structure belongs to the Inhibitory Cystin Knot structural family that consists in a compact disulfide-bonded core, from which four loops emerge. A poorly defined two-stranded antiparallel beta-sheet (residues 20-23 and 25-28) is detected. Analysis of the electrostatic charge anisotropy allows us to propose a functional map of HpTX2 different from the one described for kappa-conotoxin PVIIA, but strongly related to the one of charybdotoxin. The orientation of the dipole moment of HpTX2 emerges through K27 which could therefore be the critical lysine residue. Close to this lysine are a second basic residue, R23, an aromatic cluster (F7, W25, W30) and an hydrophobic side chain (L24). The high density in aromatic side chains of the putative functional surface as well as the lack of an asparagine is proposed to be the structural basis of the specificity of HpTX2 toward Kv4.2 channel.


==About this Structure==
Solution structure of hpTX2, a toxin from Heteropoda venatoria spider that blocks Kv4.2 potassium channel.,Bernard C, Legros C, Ferrat G, Bischoff U, Marquardt A, Pongs O, Darbon H Protein Sci. 2000 Nov;9(11):2059-67. PMID:11152117<ref>PMID:11152117</ref>
1EMX is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Heteropoda_venatoria Heteropoda venatoria]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1EMX OCA].


==Reference==
From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>
Solution structure of hpTX2, a toxin from Heteropoda venatoria spider that blocks Kv4.2 potassium channel., Bernard C, Legros C, Ferrat G, Bischoff U, Marquardt A, Pongs O, Darbon H, Protein Sci. 2000 Nov;9(11):2059-67. PMID:[http://ispc.weizmann.ac.il//pmbin/getpm?pmid=11152117 11152117]
</div>
<div class="pdbe-citations 1emx" style="background-color:#fffaf0;"></div>
== References ==
<references/>
__TOC__
</StructureSection>
[[Category: Heteropoda venatoria]]
[[Category: Heteropoda venatoria]]
[[Category: Single protein]]
[[Category: Large Structures]]
[[Category: Bernard, C.]]
[[Category: Bernard C]]
[[Category: Bishoff, U.]]
[[Category: Bishoff U]]
[[Category: Darbon, H.]]
[[Category: Darbon H]]
[[Category: Ferrat, G.]]
[[Category: Ferrat G]]
[[Category: Legros, C.]]
[[Category: Legros C]]
[[Category: Marquardt, A.]]
[[Category: Marquardt A]]
[[Category: Pongs, O.]]
[[Category: Pongs O]]
[[Category: toxin]]
 
''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 12:29:26 2008''

Latest revision as of 09:34, 30 October 2024

SOLUTION STRUCTURE OF HPTX2, A TOXIN FROM HETEROPODA VENATORIA SPIDER VENOM THAT BLOCKS KV4.2 POTASSIUM CHANNELSOLUTION STRUCTURE OF HPTX2, A TOXIN FROM HETEROPODA VENATORIA SPIDER VENOM THAT BLOCKS KV4.2 POTASSIUM CHANNEL

Structural highlights

1emx is a 1 chain structure with sequence from Heteropoda venatoria. Full experimental information is available from OCA. For a guided tour on the structure components use FirstGlance.
Method:Solution NMR, 26 models
Resources:FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT

Function

TXHP2_HETVE Inhibitor of voltage-gated potassium channels of the Kv4/KCND family. Inhibition of Kv4.3/KCND3 and Kv4.2/KCND2 is strongly voltage-dependent, while inhibition of Kv4.1/KCND1 shows less voltage-dependence. Its binding site may be near the potassium channel voltage sensor. Also blocks calcium channels.[1] [REFERENCE:2][2]

Publication Abstract from PubMed

HpTX2 is a toxin from the venom of Heteropoda venatoria spider that has been demonstrated to bind on Kv4.2 potassium channel. We have determined the solution structure of recombinant HpTX2 by use of conventional two-dimensional NMR techniques followed by distance-geometry and molecular dynamics. The calculated structure belongs to the Inhibitory Cystin Knot structural family that consists in a compact disulfide-bonded core, from which four loops emerge. A poorly defined two-stranded antiparallel beta-sheet (residues 20-23 and 25-28) is detected. Analysis of the electrostatic charge anisotropy allows us to propose a functional map of HpTX2 different from the one described for kappa-conotoxin PVIIA, but strongly related to the one of charybdotoxin. The orientation of the dipole moment of HpTX2 emerges through K27 which could therefore be the critical lysine residue. Close to this lysine are a second basic residue, R23, an aromatic cluster (F7, W25, W30) and an hydrophobic side chain (L24). The high density in aromatic side chains of the putative functional surface as well as the lack of an asparagine is proposed to be the structural basis of the specificity of HpTX2 toward Kv4.2 channel.

Solution structure of hpTX2, a toxin from Heteropoda venatoria spider that blocks Kv4.2 potassium channel.,Bernard C, Legros C, Ferrat G, Bischoff U, Marquardt A, Pongs O, Darbon H Protein Sci. 2000 Nov;9(11):2059-67. PMID:11152117[3]

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.

References

  1. Sanguinetti MC, Johnson JH, Hammerland LG, Kelbaugh PR, Volkmann RA, Saccomano NA, Mueller AL. Heteropodatoxins: peptides isolated from spider venom that block Kv4.2 potassium channels. Mol Pharmacol. 1997 Mar;51(3):491-8. PMID:9058605
  2. Zarayskiy VV, Balasubramanian G, Bondarenko VE, Morales MJ. Heteropoda toxin 2 is a gating modifier toxin specific for voltage-gated K+ channels of the Kv4 family. Toxicon. 2005 Mar 15;45(4):431-42. PMID:15733564 doi:http://dx.doi.org/S0041-0101(04)00480-5
  3. Bernard C, Legros C, Ferrat G, Bischoff U, Marquardt A, Pongs O, Darbon H. Solution structure of hpTX2, a toxin from Heteropoda venatoria spider that blocks Kv4.2 potassium channel. Protein Sci. 2000 Nov;9(11):2059-67. PMID:11152117
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