Please use this identifier to cite or link to this item:
|Title:||Proton relaxation mechanisms and the measurements of r phi, r psi and transannular interproton distances in gramicidin S.||Authors:||Niccolai, Neri
W. A., Gibbons
|Issue Date:||1984||Project:||None||Journal:||BIOPHYSICAL CHEMISTRY||Abstract:||
Monoselective, Rio(SE), biselective, Rio(i,j), and nonselective proton spin-lattice relaxation rates have been measured for dilute solutions of gramicidin S in dimethyl sulfoxide and used to evaluate cross-relaxation rates (sigma ij = Rio(i,j)-Rio(SE)) and Fi ratios (Fi = Ri(NS)/Rio(SE)). The cross-relaxation parameters, sigma, and Fi ratios measured for backbone gramicidin S protons predict that the same correlation time, tau c = 1.2 X 10(-9)s, modulates all the dipolar proton-proton interactions and that these interactions represent the main source for the proton spin-lattice relaxation process. The larger relaxation rates for amide versus alpha-protons of the backbone are attributed to dipolar relaxation between 14N and its directly bonded protons and is an approximate measure of the extent of this. The intrabackbone proton-proton distances, evaluated from sigma values, were consistent with the antiparallel beta-plated sheet/beta II'-turn conformation previously proposed for gramicidin S in solution.
|Appears in Collections:||Publications|
Show full item record
checked on May 17, 2021
Items in DSpace are protected by copyright, with all rights reserved, unless otherwise indicated.