This old version of Proteopedia is provided for student assignments while the new version is undergoing repairs. Content and edits done in this old version of Proteopedia after March 1, 2026 will eventually be lost when it is retired in about June of 2026.
Apply for new accounts at the new Proteopedia. Your logins will work in both the old and new versions.
1qmw
From Proteopedia
|
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 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
Page seeded by OCA on Thu Feb 21 14:41:29 2008
