title: Restoring Resolution in Biological Solid-State NMR under Conditions of Off-Magic-Angle Spinning.
abstract: Spin-state-selective excitation (S3E) experiments allow the selection of individual transitions in a coupled two spin system. We show that in the solid state, the dipole-dipole interaction (DD) between (15)N and (1)H in a (1)H-(15)N bond and the chemical shift anisotropy (CSA) of (15)N in an amide moiety mutually cancel each other for a particular multiplet component at high field, when the sample is spun off the magic angle (Arctan [√2] = 54.74°). The accuracy of the adjustment of the spinning angle is crucial in conventional experiments. We demonstrate that for S3E experiments, the requirement to spin the sample exactly at the magic angle is not mandatory. Applications of solid state NMR in narrow bore magnets will be facilitated where the adjustment of the magic angle is often difficult. The method opens new perspectives for the development of schemes to determine distances and to quantify dynamics in the solid state.
authors.affiliation: Helmholtz-Zentrum München (HMGU) , Deutsches Forschungszentrum für Gesundheit und Umwelt, Ingolstädter Landstrasse 1, 85764 Neuherberg, Germany.|Munich Center for Integrated Protein Science (CIPS-M) at Department Chemie, Technische Universität München (TUM) , Lichtenbergstrasse 4, 85747 Garching, Germany.
authors.forename: Riddhiman
authors.initials: R
authors.lastname: Sarkar
authors.affiliation: Helmholtz-Zentrum München (HMGU) , Deutsches Forschungszentrum für Gesundheit und Umwelt, Ingolstädter Landstrasse 1, 85764 Neuherberg, Germany.|Munich Center for Integrated Protein Science (CIPS-M) at Department Chemie, Technische Universität München (TUM) , Lichtenbergstrasse 4, 85747 Garching, Germany.
authors.forename: Diana C
authors.initials: DC
authors.lastname: Rodriguez Camargo
authors.affiliation: Université de Lyon , Institut de Sciences Analytiques, Centre de RMN à Très Hauts Champs, 5 rue de la Doua, 69100 Villeurbanne, France.
authors.forename: Guido
authors.initials: G
authors.lastname: Pintacuda
authors.affiliation: Helmholtz-Zentrum München (HMGU) , Deutsches Forschungszentrum für Gesundheit und Umwelt, Ingolstädter Landstrasse 1, 85764 Neuherberg, Germany.|Munich Center for Integrated Protein Science (CIPS-M) at Department Chemie, Technische Universität München (TUM) , Lichtenbergstrasse 4, 85747 Garching, Germany.
authors.forename: Bernd
authors.initials: B
authors.lastname: Reif
mesh_terms: D009682:Magnetic Resonance Spectroscopy / Q000379:methods*
keywords: chemical shift anisotropy; dipole−dipole interaction; spin-state-selective excitation