Microsecond motions probed by near-rotary-resonance R_1ρ¹⁵N MAS NMR experiments: the model case of protein overall-rocking in crystals.

ABSTRACT: Solid-state near-rotary-resonance measurements of the spin-lattice relaxation rate in the rotating frame (R_1ρ) is a powerful NMR technique for studying molecular dynamics in the microsecond time scale. The small difference between the spin-lock (SL) and magic-angle-spinning (MAS) frequencies allows sampling very slow motions, at the same time it brings up some methodological challenges. In this work, several issues affecting correct measurements and analysis of ¹⁵N R_1ρ data are considered in detail. Among them are signal amplitude as a function of the difference between SL and MAS frequencies, "dead time" in the initial part of the relaxation decay caused by transient spin-dynamic oscillations, measurements under HORROR condition and proper treatment of the

SUBMITTER: Krushelnitsky A 

PROVIDER: S-EPMC5986846 | biostudies-literature | 2018 May

REPOSITORIES: biostudies-literature