NMR Experiments for the measurement of carbon relaxation properties in l3C, I5N-labeled gramicidin channels

BIOL 68

Hong Gu, hgu@uark.edu, Jennifer Diaz, James F. Hinton, and Roger E. Koeppe II, rk2@uark.edu. Chemistry and Biochemistry, University of Arkansas, 101 Chem bldg, Fayetteville, AR 72701
Motional properties are important for understanding functional aspects of proteins and are accessible from NMR relaxation measurements (Biochemistry. 1987, 26, 5153; FEBS Lett. 1988, 236, 71). The goal of this study is to investigate the internal dynamics occurring in gramicidin A (gA) channels. We have synthesized several isotope-enriched gA samples, including [15N-(Val1,Gly2,Ala3,Ala5,Val7)]gA, [15N- (Leu4 ,Val6 ,Val8 , Leu10, Leu12 , Leu14 )] gA minus and [(15N,13C)-(Gly2,Ala5,Val7,Trp9)]gA, for the NMR relaxation experiments. Based upon the 15N- and 13C-NMR spectra for labeled gA samples incorporated in SDS micelles, we have been able to determine T1 values for selected backbone carbonyl carbons, and T1, T2, and NOE values for selected backbone 15NH groups. In future work, these NMR observables will be compared with the predictions of molecular dynamics simulations.
 

Frontiers in Chemical Biology
5:00 PM-7:00 PM, Sunday, August 19, 2007 BCEC -- Exhibit Hall - B2, Poster

Division of Biological Chemistry

The 234th ACS National Meeting, Boston, MA, August 19-23, 2007