Observation and Relaxation Properties of Individual Fast-Relaxing Proton Transitions in [13CH3]-Methyl-Labeled, Deuterated Proteins
 

Observation and Relaxation Properties of Individual Fast-Relaxing Proton Transitions in [13CH3]-Methyl-Labeled, Deuterated Proteins


Publication year: 2012
Source:Journal of Magnetic Resonance</br>
Hechao Sun, Vitali Tugarinov</br>
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

http://ars.sciencedirect.com/content...000742-fx1.jpg 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.</br>
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Source: Journal of Magnetic Resonance