Erschienen:
Springer Science and Business Media LLC, 2019
Erschienen in:Journal of Biomolecular NMR
Sprache:
Englisch
DOI:
10.1007/s10858-018-0219-9
ISSN:
0925-2738;
1573-5001
Entstehung:
Anmerkungen:
Beschreibung:
<jats:title>Abstract</jats:title>
<jats:p>We report linewidth and proton <jats:italic>T</jats:italic><jats:sub>1</jats:sub>, <jats:italic>T</jats:italic><jats:sub>1<jats:italic>ρ</jats:italic></jats:sub> and <jats:italic>T</jats:italic><jats:sub>2</jats:sub>′ relaxation data of the model protein ubiquitin acquired at MAS frequencies up to 126 kHz. We find a predominantly linear improvement in linewidths and coherence decay times of protons with increasing spinning frequency in the range from 93 to 126 kHz. We further attempt to gain insight into the different contributions to the linewidth at fast MAS using site-specific analysis of proton relaxation parameters and present bulk relaxation times as a function of the MAS frequency. For microcrystalline fully-protonated ubiquitin, inhomogeneous contributions are only a minor part of the proton linewidth, and at 126 kHz MAS coherent effects are still dominating. We furthermore present site-specific proton relaxation rate constants during a spinlock at 126 kHz MAS, as well as MAS-dependent bulk <jats:italic>T</jats:italic><jats:sub>1ρ</jats:sub> (<jats:sup>1</jats:sup>H<jats:sup>N</jats:sup>).</jats:p>