Quantitative measurement of exchange dynamics in proteins via 13C relaxation dispersion of 13CHD2-labeled samples
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Methyl groups have emerged as powerful probes of protein dynamics with timescales from picoseconds to seconds. Typically, studies involving high molecular weight complexes exploit 13CH3- or 13CHD2-labeling in otherwise highly deuterated proteins. The 13CHD2 label offers the unique advantage of providing 13C, 1H and 2H spin probes, however a disadvantage has been the lack of an experiment to record 13C Carr–Purcell–Meiboom–Gill relaxation dispersion that monitors millisecond time-scale dynamics, implicated in a wide range of biological processes. Herein we develop an experiment that eliminates artifacts that would normally result from the scalar coupling between 13C and 2H spins that has limited applications in the past. The utility of the approach is established with a number of applications, including measurement of ms dynamics of a disease mutant of a 320 kDa p97 complex.
KeywordsCPMG Conformational dynamics Proteins Methyl labeling Relaxation dispersion 13CHD2
A.K.S is the recipient of an EMBO Long Term Fellowship and an Early Postdoc Mobility Fellowship from the Swiss National Science Foundation. This work was funded through a Canadian Institute of Health Research grant to L.E.K. L.E.K. holds a Canada Research Chair in Biochemistry.
- Abragam A (1961) Principles of nuclear magnetism. Clarendon Press, OxfordGoogle Scholar
- Otten R, Villali J, Kern D, Mulder FA (2010) Probing microsecond time scale dynamics in proteins by methyl 1H Carr–Purcell–Meiboom–Gill relaxation dispersion NMR measurements. Application to activation of the signaling protein NtrC(r). J Am Chem Soc 132:17004–17014. doi: 10.1021/ja107410x CrossRefGoogle Scholar