Observation and Relaxation Properties of Individual Fast-Relaxing Proton Transitions in [CH3]-Methyl-Labeled, Deuterated Proteins
Publication year: 2012
Source: Journal of Magnetic Resonance, Available online 2 March 2012
Hechao*Sun, Vitali*Tugarinov
A pair of NMR experiments is developed for separation of individual fast-relaxing transitions inCH3methyl groups of methyl-protonated, highly deuterated proteins, and the measurement of their relaxation rates. Intra-methylH-H/H-C dipole-dipole cross-correlated spin relaxation that differentiates the rates of the fast-relaxing transitions depending on the state ofC spins, is measured in the selectively [CH3]-methyl-labeled, deuterated ubiquitin at 10, 27, and 40 °C. In contrast with previous observations, theH-H/H-C 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
Highlights
? Experiments are presented for separation of individualH transitions in methyls. ? Intra-methylH-H/H-C cross-correlations in these transitions are quantified.H-H/H-C cross-correlations serve as good measures of side-chain ordering.
Source:
Journal of Magnetic Resonance