Changes in polypeptide conformer populations induced by the solvent environment

✍ Scribed by F. Xu; T. A. Cross

• Publisher: John Wiley and Sons
• Year: 1998
• Tongue: English
• Weight: 234 KB
• Volume: 36
• Category: Article
• ISSN: 0749-1581
• DOI: 10.1002/(sici)1097-458x(199809)36:9<651::aid-omr341>3.0.co;2-6

✦ Synopsis

Changes in the solvent dielectric properties are correlated with changes in polypeptide conformer populations. Gramicidin A, a peptide native to membrane environments, forms a variety of well deÐned dimeric conformations in relatively low dielectric organic solvents. However, changes in this environment lead to changes in the conformer populations with the lowest dielectric solvents favoring the conformers with the lowest net dipole moment. Such changes were characterized by cross-peak intensities in GCOSY solution NMR spectra. In studying membrane-bound polypeptides, it is very important to recognize that the structure is not dictated by just the amino acid sequence, but that the environment plays a very signiÐcant role in deÐning the polypeptide conformation.