title: NMR chemical shifts and structure refinement in proteins.
abstract: Computation of the 13C alpha chemical shifts (or shieldings) of glycine, alanine and valine residues in bovine and Drosophila calmodulins and Staphylococcal nuclease, and comparison with experimental values, is reported using a gauge-including atomic orbital quantum-chemical approach. The full approximately 24 ppm shielding range is reproduced (overall r.m.s.d. = 1.4 ppm) using 'optimized' protein structures, corrected for bond-length/bond-angle errors, and rovibrational effects.
authors.affiliation: Department of Chemistry, University of Illinois at Urbana-Champaign 61801.
authors.forename: D D
authors.initials: DD
authors.lastname: Laws
authors.forename: A C
authors.initials: AC
authors.lastname: de Dios
authors.forename: E
authors.initials: E
authors.lastname: Oldfield
mesh_terms: D000409:Alanine; D000818:Animals; D002147:Calmodulin / Q000737:chemistry*; D002417:Cattle; D004330:Drosophila; D005998:Glycine; D009682:Magnetic Resonance Spectroscopy / Q000379:methods*; D008836:Micrococcal Nuclease / Q000737:chemistry*; D008969:Molecular Sequence Data; D011487:Protein Conformation; D011506:Proteins / Q000737:chemistry*; D014633:Valine
chemical_list: D002147:Calmodulin; D011506:Proteins; D008836:Micrococcal Nuclease; D014633:Valine; D000409:Alanine; D005998:Glycine