title: Accurate measurement of longitudinal cross-relaxation rates in nuclear magnetic resonance.
abstract: The accuracy of the determination of longitudinal cross-relaxation rates in NMR can be improved by combining symmetrical reconversion with suitable operator swapping methods that lead to the averaging of differences in autorelaxation rates and eliminate the effects of cross relaxation with the environment. The principles are first discussed for an isolated two-spin system comprising a pair of 15N and 1HN nuclei subjected to chemical shift anisotropy and dipole-dipole relaxation, and then extended to include further protons. The gains in accuracy are demonstrated experimentally for the protein ubiquitin.
authors: Département de Chimie, Associé au CNRS, Ecole Normale Supérieure, 24 rue Lhomond, 75231 Paris Cedex 05, France. philippe.pelupessy@ens.fr
authors: Philippe
authors: P
authors: Pelupessy
authors: Fabien
authors: F
authors: Ferrage
authors: Geoffrey
authors: G
authors: Bodenhausen
mesh_terms: D000465:Algorithms; D016880:Anisotropy; D002247:Carbon Isotopes / Q000737:chemistry; D002627:Chemistry, Physical / Q000379:methods; D008279:Magnetic Resonance Imaging / Q000379:methods; D009682:Magnetic Resonance Spectroscopy / Q000379:methods*; D015233:Models, Statistical; D008962:Models, Theoretical; D009587:Nitrogen Isotopes / Q000737:chemistry; D011487:Protein Conformation; D011522:Protons; D013696:Temperature; D025801:Ubiquitin / Q000737:chemistry*
chemical_list: D002247:Carbon Isotopes; D009587:Nitrogen Isotopes; D011522:Protons; D025801:Ubiquitin