title: Determination of protein rotational correlation time from NMR relaxation data at various solvent viscosities.
abstract: An accurate determination of the overall rotation of a protein plays a crucial role in the investigation of its internal motions by NMR. In the present work, an innovative approach to the determination of the protein rotational correlation time tau(R) from the heteronuclear relaxation data is proposed. The approach is based on a joint fit of relaxation data acquired at several viscosities of a protein solution. The method has been tested on computer simulated relaxation data as compared to the traditional tau(R) determination method from T(1)/T(2) ratio. The approach has been applied to ribonuclease barnase from Bacillus amyloliquefaciens dissolved in an aqueous solution and deuterated glycerol as a viscous component. The resulting rotational correlation time of 5.56 +/- 0.01 ns and other rotational diffusion tensor parameters are in good agreement with those determined from T(1)/T(2) ratio.
authors.affiliation: Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, ul. Miklukho-Maklaya, 16/10, Moscow, 117997, Russia.
authors.forename: Denis S
authors.initials: DS
authors.lastname: Korchuganov
authors.forename: Ivan E
authors.initials: IE
authors.lastname: Gagnidze
authors.forename: Elena N
authors.initials: EN
authors.lastname: Tkach
authors.forename: Alexey A
authors.initials: AA
authors.lastname: Schulga
authors.forename: Mikhail P
authors.initials: MP
authors.lastname: Kirpichnikov
authors.forename: Alexander S
authors.initials: AS
authors.lastname: Arseniev
mesh_terms: D001407:Bacillus / Q000201:enzymology; D001426:Bacterial Proteins; D006859:Hydrogen / Q000737:chemistry; D008958:Models, Molecular; D019906:Nuclear Magnetic Resonance, Biomolecular; D017434:Protein Structure, Tertiary; D012260:Ribonucleases / Q000737:chemistry*; D012399:Rotation; D012997:Solvents / Q000737:chemistry*; D013997:Time Factors; D014783:Viscosity
chemical_list: D001426:Bacterial Proteins; D012997:Solvents; D006859:Hydrogen; D012260:Ribonucleases; C019760:Bacillus amyloliquefaciens ribonuclease