Solution Structure of a β-Neurotoxin from the New World ScorpionCentruroides sculpturatusEwing
| Autor: | J.O Trent, Dean D. Watt, Michael J. Jablonsky, N.R. Krishna, Patricia L. Jackson |
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| Rok vydání: | 1999 |
| Předmět: |
Models
Molecular Protein Conformation Molecular Sequence Data Neurotoxins Static Electricity Biophysics Scorpion Venoms Sequence alignment Dihedral angle Antiparallel (biochemistry) Biochemistry Protein Structure Secondary Scorpions Protein structure Static electricity Animals Computer Simulation Amino Acid Sequence Nuclear Magnetic Resonance Biomolecular Molecular Biology Sequence Homology Amino Acid Chemistry Protein primary structure Cell Biology Solutions Crystallography Proton NMR Sequence Alignment Two-dimensional nuclear magnetic resonance spectroscopy |
| Zdroj: | Biochemical and Biophysical Research Communications. 254:406-412 |
| ISSN: | 0006-291X |
| DOI: | 10.1006/bbrc.1998.9904 |
| Popis: | 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. |
| Databáze: | OpenAIRE |
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