Dependence of amino acid side chain 13C shifts on dihedral angle: application to conformational analysis.

ABSTRACT: Chemical shift data from the BiomagResDataBank and conformational data derived from the protein data bank have been correlated in order to explore the conformational dependence of side chain (13)C resonance shifts. Consistent with predictions based on steric compression, upfield shifts for Cgamma resonances of Thr, Val, Ile, Leu, Met, Arg, Lys, Glu, and Gln residues correlate with both the number of heavy atom (nonproton) gamma-substituents and with gauche conformational orientations of gamma-substituents. The (13)C shift/conformation correlations are most apparent for Cgamma carbons but also can be observed at positions further from the backbone. Intraresidue steric conflict leads to a correlation between upfield-shifted side chain (13)C resonances and statistically lower probabilities in

SUBMITTER: London RE 

PROVIDER: S-EPMC2712834 | biostudies-literature | 2008 Aug

REPOSITORIES: biostudies-literature