title: Correlated motions of successive amide N-H bonds in proteins.
abstract: New nuclear magnetic resonance (NMR) methods are described for the measurement of cross-correlation rates of zero- and double-quantum coherences involving two nitrogen nuclei belonging to successive amino acids in proteins and peptides. Rates due to the concerted fluctuations of two NH(N) dipole-dipole interactions and to the correlated modulations of two nitrogen chemical shift anisotropies have been obtained in a sample of doubly labeled Ubiquitin. Ambiguities in the determination of dihedral angles can be lifted by comparison of different rates. By defining a heuristic order parameter, experimental rates can be compared with those expected for a rigid molecule. The cross-correlation order parameter that can be derived from a model-free approach can be separated into structural and dynamic contributions.
authors.affiliation: Département de chimie, associé au CNRS, Ecole Normale Supérieure, 24 rue Lhomond, 75231 Paris cedex 05, France.
authors.forename: Philippe
authors.initials: P
authors.lastname: Pelupessy
authors.forename: Sapna
authors.initials: S
authors.lastname: Ravindranathan
authors.forename: Geoffrey
authors.initials: G
authors.lastname: Bodenhausen
mesh_terms: D000577:Amides / Q000737:chemistry*; D007553:Isotope Labeling; D008280:Magnetics; D008962:Models, Theoretical; D009038:Motion; D009587:Nitrogen Isotopes; D019906:Nuclear Magnetic Resonance, Biomolecular / Q000379:methods*; D011506:Proteins / Q000737:chemistry*; D025801:Ubiquitin / Q000737:chemistry
chemical_list: D000577:Amides; D009587:Nitrogen Isotopes; D011506:Proteins; D025801:Ubiquitin