title: Immobilization of soluble protein complexes in MAS solid-state NMR: Sedimentation versus viscosity.
abstract: In recent years, MAS solid-state NMR has emerged as a technique for the investigation of soluble protein complexes. It was found that high molecular weight complexes do not need to be crystallized in order to obtain an immobilized sample for solid-state NMR investigations. Sedimentation induced by sample rotation impairs rotational diffusion of proteins and enables efficient dipolar coupling based cross polarization transfers. In addition, viscosity contributes to the immobilization of the molecules in the sample. Natural Deep Eutectic Solvents (NADES) have very high viscosities, and can replace water in living organisms. We observe a considerable amount of cross polarization transfers for NADES solvents, even though their molecular weight is too low to yield significant sedimentation. We discuss how viscosity and sedimentation both affect the quality of the obtained experimental spectra. The FROSTY/sedNMR approach holds the potential to study large protein complexes, which are otherwise not amenable for a structural characterization using NMR. We show that using this method, backbone assignments of the symmetric proteasome activator complex (1.1MDa), and high quality correlation spectra of non-symmetric protein complexes such as the prokaryotic ribosome 50S large subunit binding to trigger factor (1.4MDa) are obtained.
authors.affiliation: Munich Center for Integrated Protein Science (CIPSM) at Department of Chemie, Technische Universität München (TUM), Lichtenbergstr. 4, D-85747 Garching, Germany; Helmholtz-Zentrum München, Deutsches Forschungszentrum für Gesundheit und Umwelt (HMGU), Ingolstädter Landstr. 1, D-85764 Neuherberg, Germany.
authors.forename: Riddhiman
authors.initials: R
authors.lastname: Sarkar
authors.affiliation: Munich Center for Integrated Protein Science (CIPSM) at Department of Chemie, Technische Universität München (TUM), Lichtenbergstr. 4, D-85747 Garching, Germany; Helmholtz-Zentrum München, Deutsches Forschungszentrum für Gesundheit und Umwelt (HMGU), Ingolstädter Landstr. 1, D-85764 Neuherberg, Germany; Technische Universität Berlin, Fakultät II Mathematik und Naturwissenschaften, Institut für Chemie/OC/Biologische Chemie, Müller-Breslau-Straße 10, 10623 Berlin, Germany.
authors.forename: Andi
authors.initials: A
authors.lastname: Mainz
authors.affiliation: Munich Center for Integrated Protein Science (CIPSM) at Department of Chemie, Technische Universität München (TUM), Lichtenbergstr. 4, D-85747 Garching, Germany; Helmholtz-Zentrum München, Deutsches Forschungszentrum für Gesundheit und Umwelt (HMGU), Ingolstädter Landstr. 1, D-85764 Neuherberg, Germany.
authors.forename: Baptiste
authors.initials: B
authors.lastname: Busi
authors.affiliation: Munich Center for Integrated Protein Science (CIPSM) at Department of Chemie, Technische Universität München (TUM), Lichtenbergstr. 4, D-85747 Garching, Germany; Helmholtz-Zentrum München, Deutsches Forschungszentrum für Gesundheit und Umwelt (HMGU), Ingolstädter Landstr. 1, D-85764 Neuherberg, Germany.
authors.forename: Emeline
authors.initials: E
authors.lastname: Barbet-Massin
authors.affiliation: Chair of Food Chemistry and Molecular Sensory Science, Technische Universitat¨ Mu¨nchen, Lise-Meitner-Strasse 34, 85354 Freising, Germany.
authors.forename: Maximilian
authors.initials: M
authors.lastname: Kranz
authors.affiliation: Chair of Food Chemistry and Molecular Sensory Science, Technische Universitat¨ Mu¨nchen, Lise-Meitner-Strasse 34, 85354 Freising, Germany.
authors.forename: Thomas
authors.initials: T
authors.lastname: Hofmann
authors.affiliation: Munich Center for Integrated Protein Science (CIPSM) at Department of Chemie, Technische Universität München (TUM), Lichtenbergstr. 4, D-85747 Garching, Germany; Helmholtz-Zentrum München, Deutsches Forschungszentrum für Gesundheit und Umwelt (HMGU), Ingolstädter Landstr. 1, D-85764 Neuherberg, Germany. Electronic address: reif@tum.de.
authors.forename: Bernd
authors.initials: B
authors.lastname: Reif
mesh_terms: D000818:Animals; D006801:Humans; D055767:Immobilized Proteins; D008279:Magnetic Resonance Imaging; D009682:Magnetic Resonance Spectroscopy; D012997:Solvents
chemical_list: D055767:Immobilized Proteins; D012997:Solvents
keywords: Magic angle spinning; Perdeuteration; Sedimentation; Soluble protein complexes; Viscosity