Secondary and tertiary structural effects on protein NMR chemical shifts: an ab initio approach.
Recent theoretical developments permit the prediction of 1H, 13C, 15N, and 19F nuclear magnetic resonance chemical shifts in proteins and offer new ways of analyzing secondary and tertiary structure as well as for probing protein electrostatics. For 13C, phi, psi torsion angles dominate shielding for C alpha and C beta, but the addition of hydrogen bonding and electrostatics gives even better accord with experiment. For 15NH, side chain (chi 1) torsion angles are also important, as are nearest neighbor sequence effects, whereas for 1HN, hydrogen bonding is particularly significant. For 19F, weak or long-range electrostatic fields dominate 19F shielding nonequivalencies. The ability to predict chemical shifts in proteins from known or test structures opens new avenues to structure refinement or determination, especially for condensed systems.
de Dios
A C
AC
Department of Chemistry, University of Illinois, Urbana-Champaign 61801.
Pearson
J G
JG
Oldfield
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E
D001426:Bacterial Proteins / Q000737:chemistry; D002135:Calcium-Binding Proteins; D002352:Carrier Proteins / Q000737:chemistry; D009682:Magnetic Resonance Spectroscopy; D008956:Models, Chemical; D008958:Models, Molecular; D009004:Monosaccharide Transport Proteins; D033902:Periplasmic Binding Proteins; D017433:Protein Structure, Secondary; D017434:Protein Structure, Tertiary; D011506:Proteins / Q000737:chemistry*
D001426:Bacterial Proteins; D002135:Calcium-Binding Proteins; D002352:Carrier Proteins; D009004:Monosaccharide Transport Proteins; D033902:Periplasmic Binding Proteins; D011506:Proteins; C023550:galactose-binding protein