title: 3hJ coupling between C(alpha) and H(N) across hydrogen bonds in proteins.
abstract: J couplings between (13)C(alpha) and (1)H(N) across hydrogen bonds in proteins are reported for the first time, and a two- or three-dimensional NMR technique for their measurement is presented. The technique exploits the TROSY effect, i.e., the degree of interference between dipolar and chemical shift anisotropy relaxation mechanisms, for sensitivity enhancement. The 2D or 3D spectra exhibit E.COSY patterns where the splittings in the (13)CO and (1)H(N) dimensions are (1)J((13)C(alpha), (13)CO) and the desired (3h)J((13)C(alpha), (1)H(N)), respectively. A demonstration of the new method is shown for the (15)N,(13)C-labeled protein chymotrypsin inhibitor 2 where 17 (3h)J((13)C(alpha), (1)H(N)) coupling constants ranging from 0 to 1.4 Hz where identified and all of positive sign.
authors.affiliation: Department of Chemistry, Carlsberg Laboratory, Gamle Carlsberg Vej 10, Valby, DK-2500, Denmark.
authors.forename: A
authors.initials: A
authors.lastname: Meissner
authors.forename: O W
authors.initials: OW
authors.lastname: Sorensen
mesh_terms: D002244:Carbon / Q000737:chemistry*; D002247:Carbon Isotopes; D002918:Chymotrypsin / Q000037:antagonists & inhibitors; D004578:Electron Spin Resonance Spectroscopy; D006859:Hydrogen / Q000737:chemistry*; D006860:Hydrogen Bonding; D009682:Magnetic Resonance Spectroscopy / Q000379:methods*; D009584:Nitrogen / Q000737:chemistry; D009587:Nitrogen Isotopes; D010100:Oxygen / Q000737:chemistry; D010455:Peptides / Q000737:chemistry; D010940:Plant Proteins; D011487:Protein Conformation; D011506:Proteins / Q000737:chemistry*; D012680:Sensitivity and Specificity; D015842:Serine Proteinase Inhibitors / Q000737:chemistry
chemical_list: D002247:Carbon Isotopes; D009587:Nitrogen Isotopes; D010455:Peptides; D010940:Plant Proteins; D011506:Proteins; D015842:Serine Proteinase Inhibitors; C093336:chymotrypsin inhibitor 2; D002244:Carbon; D006859:Hydrogen; D002918:Chymotrypsin; D009584:Nitrogen; D010100:Oxygen