1qmw
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(New page: 200px<br /><applet load="1qmw" size="450" color="white" frame="true" align="right" spinBox="true" caption="1qmw" /> '''SOLUTION STRUCTURE OF ALPHA-CONOTOXIN SI'''<...)
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Revision as of 22:41, 20 November 2007
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SOLUTION STRUCTURE OF ALPHA-CONOTOXIN SI
Overview
The nuclear magnetic resonance solution structure of alpha-conotoxin SI, has been determined at pH 4.2. The 36 lowest energy structures show that, alpha-conotoxin SI exists in a single major solution conformation and is, stabilized by six hydrogen bonds. Comparisons are made between the SI, solution structure and the solution and crystal structures of, alpha-conotoxin GI. Surprisingly, a high degree of similarity between the, backbone conformations of the GI crystal and the SI solution structures is, seen in the region of lowest sequence homology, namely residues Gly-8 to, Ser-12. This similarity is more surprising when considering that in SI a, proline replaces the Arg-9 found in GI. The correspondence in conformation, in this region provides the definitive evidence that it is the loss of the, arginine basic charge at residue 9 which determines the differences in, toxicity between GI and SI, rather than any changes in conformation, induced by the cyclic proline residue.
About this Structure
1QMW is a Single protein structure of sequence from Conus striatus with NH2 as ligand. Full crystallographic information is available from OCA.
Reference
Solution structure of alpha-conotoxin SI., Benie AJ, Whitford D, Hargittai B, Barany G, Janes RW, FEBS Lett. 2000 Jul 7;476(3):287-95. PMID:10913630
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