Observation and Relaxation Properties of Individual Fast-Relaxing Proton Transitions in [13CH3]-Methyl-Labeled, Deuterated Proteins
Publication year: 2012
Source:Journal of Magnetic Resonance
Hechao Sun, Vitali Tugarinov
A pair of NMR experiments is developed for separation of individual fast-relaxing transitions in 13CH3 methyl groups of methyl-protonated, highly deuterated proteins, and the measurement of their relaxation rates. Intra-methyl 1H-1H/1H-13C dipole-dipole cross-correlated spin relaxation that differentiates the rates of the fast-relaxing transitions depending on the state of 13C spins, is measured in the selectively [13CH3]-methyl-labeled, deuterated ubiquitin at 10, 27, and 40 °C. In contrast with previous observations, the 1H-1H/1H-13C cross-correlated relaxation rates measured from relaxation rates of single-quantum proton transitions serve as good measures of side-chain order even in proteins with global rotational correlation times significantly less than 10 ns.
Graphical Abstract
Graphical abstract Highlights
? Experiments are presented for separation of individual 1H transitions in methyls. ? Intra-methyl 1H-1H/1H-13 C cross-correlations in these transitions are quantified. ? 1H-1H/1H-13C cross-correlations serve as good measures of side-chain ordering.
Source:
Journal of Magnetic Resonance