1emx
From Proteopedia
(New page: 200px<br /><applet load="1emx" size="450" color="white" frame="true" align="right" spinBox="true" caption="1emx" /> '''SOLUTION STRUCTURE OF HPTX2, A TOXIN FROM HE...) |
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| - | [[Image:1emx.jpg|left|200px]]<br /><applet load="1emx" size=" | + | [[Image:1emx.jpg|left|200px]]<br /><applet load="1emx" size="350" color="white" frame="true" align="right" spinBox="true" |
caption="1emx" /> | caption="1emx" /> | ||
'''SOLUTION STRUCTURE OF HPTX2, A TOXIN FROM HETEROPODA VENATORIA SPIDER VENOM THAT BLOCKS KV4.2 POTASSIUM CHANNEL'''<br /> | '''SOLUTION STRUCTURE OF HPTX2, A TOXIN FROM HETEROPODA VENATORIA SPIDER VENOM THAT BLOCKS KV4.2 POTASSIUM CHANNEL'''<br /> | ||
==Overview== | ==Overview== | ||
| - | HpTX2 is a toxin from the venom of Heteropoda venatoria spider that has | + | 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== | ==About this Structure== | ||
| - | 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:// | + | 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== | ==Reference== | ||
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[[Category: toxin]] | [[Category: toxin]] | ||
| - | ''Page seeded by [http:// | + | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 12:29:26 2008'' |
Revision as of 10:29, 21 February 2008
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SOLUTION STRUCTURE OF HPTX2, A TOXIN FROM HETEROPODA VENATORIA SPIDER VENOM THAT BLOCKS KV4.2 POTASSIUM CHANNEL
Overview
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
1EMX is a Single protein structure of sequence from Heteropoda venatoria. Full crystallographic information is available from OCA.
Reference
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
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