Solution structure of α‐conotoxin SI

FEBS Letters

Hargittai, Balazs²  Benie, Andrew J.³  Janes, Robert W.¹  Barany, George²  Whitford, David³ 

[1] School of Biological Sciences, Queen Mary and Westfield College, University of London, Mile End Road, London E1 4NS, UK;Department of Chemistry, University of Minnesota, 207 Pleasant St. S.E., Minneapolis, MN 55455, USA;Molecular and Cellular Biology, Division of Biomedical Sciences, St. Bartholomew's and the Royal London School of Medicine and Dentistry, Queen Mary and Westfield College, University of London, Mile End Road, London E1 4NS, UK

关键词: Conotoxin;    Nuclear magnetic resonance;    Three-dimensional structure;    Nicotinic acetylcholine receptor;    Circular dichroism;    Disulfide linked peptide;    ACh;    acetylcholine;    CD;    circular dichroism;    LED;    longitudinal eddy current delay;    nAChR;    nicotinic acetylcholine receptor;    RAPL;    relative amide proton lifetime;    RMSD;    root mean square deviation;   

DOI  :  10.1016/S0014-5793(00)01724-5

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

The nuclear magnetic resonance solution structure of α-conotoxin SI has been determined at pH 4.2. The 36 lowest energy structures show that α-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 α-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.

【 授权许可】

Unknown