1coe
From Proteopedia
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SOLUTION CONFORMATION OF COBROTOXIN: A NUCLEAR MAGNETIC RESONANCE AND HYBRID DISTANCE GEOMETRY-DYNAMICAL SIMULATED ANNEALING STUDY
Overview
The solution conformation of cobrotoxin has been determined by using, proton nuclear magnetic resonance spectroscopy. With the combination of, various two-dimensional NMR techniques, the 1H-NMR spectrum of cobrotoxin, was completely assigned (Yu et al., 1990). A set of 435 approximate, interproton distance restraints was derived from nuclear Overhauser, enhancement (NOE) measurements. These NOE constraints, in addition to the, 29 dihedral angle constraints (from coupling constant measurements) and 26, hydrogen bonding restraints (from the pattern of short-range NOEs), form, the basis of 3-D structure determination by the hybrid distance, geometry-dynamical simulated annealing method. The 23 structures that were, obtained satisfy the experimental restraints, display small deviation from, idealized covalent geometry, and possess good nonbonded contacts. Analysis, of converged structures indicated that there are two antiparallel beta, sheets (double and triple stranded), duly confirming our earlier, observations. These are well defined in terms of both atomic root mean, square (RMS) differences and backbone torsional angles. The average, backbone RMS deviation between the calculated structures and the mean, structure, for the beta-sheet regions, is 0.92 A. The mean solution, structure was compared with the X-ray crystal structure of erabutoxin b, the homologous protein. This yielded information that both structures, resemble each other except at the exposed loop/surface regions, where the, solution structure seems to possess more flexibility.
About this Structure
1COE is a Single protein structure of sequence from Naja atra. Full crystallographic information is available from OCA.
Reference
Solution conformation of cobrotoxin: a nuclear magnetic resonance and hybrid distance geometry-dynamical simulated annealing study., Yu C, Bhaskaran R, Chuang LC, Yang CC, Biochemistry. 1993 Mar 9;32(9):2131-6. PMID:8443154
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