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2b3c
From Proteopedia
(New page: 200px<br /><applet load="2b3c" size="450" color="white" frame="true" align="right" spinBox="true" caption="2b3c" /> '''SOLUTION STRUCTURE OF A BETA-NEUROTOXIN FROM...) |
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| - | [[Image:2b3c.jpg|left|200px]]<br /><applet load="2b3c" size=" | + | [[Image:2b3c.jpg|left|200px]]<br /><applet load="2b3c" size="350" color="white" frame="true" align="right" spinBox="true" |
caption="2b3c" /> | caption="2b3c" /> | ||
'''SOLUTION STRUCTURE OF A BETA-NEUROTOXIN FROM THE NEW WORLD SCORPION CENTRUROIDES SCULPTURATUS EWING'''<br /> | '''SOLUTION STRUCTURE OF A BETA-NEUROTOXIN FROM THE NEW WORLD SCORPION CENTRUROIDES SCULPTURATUS EWING'''<br /> | ||
==Overview== | ==Overview== | ||
| - | We report the detailed solution structure of the 7.2 kDa protein CsE-I, a | + | We report the detailed solution structure of the 7.2 kDa protein CsE-I, a beta-neurotoxin from the New World scorpion Centruroides sculpturatus Ewing. This toxin binds to sodium channels, but unlike the alpha-neurotoxins, shifts the voltage of activation toward more negative potentials causing the membrane to fire spontaneously. Sequence-specific proton NMR assignments were made using 600 MHz 2D-NMR data. Distance geometry and dynamical simulated annealing refinements were performed using experimental distance and torsion angle constraints from NOESY and pH-COSY data. A family of 40 structures without constraint violations was generated, and an energy-minimized average structure was computed. The backbone conformation of the CsE-I toxin shows similar secondary structural features as the prototypical alpha-neurotoxin, CsE-v3, and is characterized by a short 2(1/2)-turn alpha-helix and a 3-strand antiparallel beta-sheet, both held together by disulfide bridges. The RMSD for the backbone atoms between CsE-I and CsE-v3 is 1.48 A. Despite this similarity in the overall backbone folding, the these two proteins show some important differences in the primary structure (sequence) and electrostatic potential surfaces. Our studies provide a basis for unravelling the role of these differences in relation to the known differences in the receptor sites on the voltage sensitive sodium channel for the alpha- and beta-neurotoxins. |
==About this Structure== | ==About this Structure== | ||
| - | 2B3C is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Centruroides_sculpturatus Centruroides sculpturatus]. Full crystallographic information is available from [http:// | + | 2B3C is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Centruroides_sculpturatus Centruroides sculpturatus]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=2B3C OCA]. |
==Reference== | ==Reference== | ||
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[[Category: Centruroides sculpturatus]] | [[Category: Centruroides sculpturatus]] | ||
[[Category: Single protein]] | [[Category: Single protein]] | ||
| - | [[Category: Jablonsky, M | + | [[Category: Jablonsky, M J.]] |
| - | [[Category: Jackson, P | + | [[Category: Jackson, P L.]] |
| - | [[Category: Krishna, N | + | [[Category: Krishna, N R.]] |
| - | [[Category: Trent, J | + | [[Category: Trent, J O.]] |
| - | [[Category: Watt, D | + | [[Category: Watt, D D.]] |
[[Category: beta-toxin]] | [[Category: beta-toxin]] | ||
[[Category: new world toxin]] | [[Category: new world toxin]] | ||
[[Category: scorpion neurotoxin]] | [[Category: scorpion neurotoxin]] | ||
| - | ''Page seeded by [http:// | + | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 16:33:42 2008'' |
Revision as of 14:33, 21 February 2008
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SOLUTION STRUCTURE OF A BETA-NEUROTOXIN FROM THE NEW WORLD SCORPION CENTRUROIDES SCULPTURATUS EWING
Overview
We report the detailed solution structure of the 7.2 kDa protein CsE-I, a beta-neurotoxin from the New World scorpion Centruroides sculpturatus Ewing. This toxin binds to sodium channels, but unlike the alpha-neurotoxins, shifts the voltage of activation toward more negative potentials causing the membrane to fire spontaneously. Sequence-specific proton NMR assignments were made using 600 MHz 2D-NMR data. Distance geometry and dynamical simulated annealing refinements were performed using experimental distance and torsion angle constraints from NOESY and pH-COSY data. A family of 40 structures without constraint violations was generated, and an energy-minimized average structure was computed. The backbone conformation of the CsE-I toxin shows similar secondary structural features as the prototypical alpha-neurotoxin, CsE-v3, and is characterized by a short 2(1/2)-turn alpha-helix and a 3-strand antiparallel beta-sheet, both held together by disulfide bridges. The RMSD for the backbone atoms between CsE-I and CsE-v3 is 1.48 A. Despite this similarity in the overall backbone folding, the these two proteins show some important differences in the primary structure (sequence) and electrostatic potential surfaces. Our studies provide a basis for unravelling the role of these differences in relation to the known differences in the receptor sites on the voltage sensitive sodium channel for the alpha- and beta-neurotoxins.
About this Structure
2B3C is a Single protein structure of sequence from Centruroides sculpturatus. Full crystallographic information is available from OCA.
Reference
Solution structure of a beta-neurotoxin from the New World scorpion Centruroides sculpturatus Ewing., Jablonsky MJ, Jackson PL, Trent JO, Watt DD, Krishna NR, Biochem Biophys Res Commun. 1999 Jan 19;254(2):406-12. PMID:9918851
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