title: Microsecond time scale mobility in a solid protein as studied by the 15N R(1rho) site-specific NMR relaxation rates.
abstract: For the first time, we have demonstrated the site-resolved measurement of reliable (i.e., free of interfering effects) (15)N R(1rho) relaxation rates from a solid protein to extract dynamic information on the microsecond time scale. (15)N R(1rho) NMR relaxation rates were measured as a function of the residue number in a (15)N,(2)H-enriched (with 10-20% back-exchanged protons at labile sites) microcrystalline SH3 domain of chicken alpha-spectrin. The experiments were performed at different temperatures and at different spin-lock frequencies, which were realized by on- and off-resonance spin-lock irradiation. The results obtained indicate that the interfering spin-spin contribution to the R(1rho) rate in a perdeuterated protein is negligible even at low spin-lock fields, in contrast to the case for normal protonated samples. Through correlation plots, the R(1rho) rates were compared with previous data for the same protein characterizing different kinds of internal mobility.
authors.affiliation: Kazan Institute of Biochemistry and Biophysics, Kazan, Russia. Krushelnitsky@mail.knc.ru
authors.forename: Alexey
authors.initials: A
authors.lastname: Krushelnitsky
authors.forename: Tatiana
authors.initials: T
authors.lastname: Zinkevich
authors.forename: Detlef
authors.initials: D
authors.lastname: Reichert
authors.forename: Veniamin
authors.initials: V
authors.lastname: Chevelkov
authors.forename: Bernd
authors.initials: B
authors.lastname: Reif
mesh_terms: D000818:Animals; D002645:Chickens; D009682:Magnetic Resonance Spectroscopy; D013049:Spectrin / Q000737:chemistry*; D013696:Temperature; D013997:Time Factors
chemical_list: D013049:Spectrin