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Abstract NMR relaxation dispersion spectroscopy is a powerful method for studying protein conformational dynamics whereby visible, ground and invisible, excited conformers interconvert on the millisecond time-scale. In addition to providing kinetics and thermodynamics parameters of the exchange process, the CPMG dispersion experiment also allows extraction of the absolute values of the chemical shift differences between interconverting states,
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ê \Updelta ~

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ê
ê , opening the way for structure determination of excited state conformers. Central to the goal of structural analysis is the availability of the chemical shifts of the excited state that can only be obtained once the signs of
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are known. Herein we describe a very simple method for determining the signs of 1HN
\Updelta ~

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values based on a comparison of peak positions in the directly detected dimensions of a pair of 1HNâ??15N correlation maps recorded at different static magnetic fields. The utility of the approach is demonstrated for three proteins that undergo millisecond time-scale conformational rearrangements. Although the method provides fewer signs than previously published techniques it does have a number of strengths: (1) Data sets needed for analysis are typically available from other experiments, such as those required for measuring signs of 15N
\Updelta ~

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values, thus requiring no additional experimental time, (2) acquisition times in the critical detection dimension can be as long as necessary and (3) the signs obtained can be used to cross-validate those from other approaches.

• Content Type Journal Article
• DOI 10.1007/s10858-010-9418-8
• Authors
  • Guillaume Bouvignies, The University of Toronto Departments of Molecular Genetics, Biochemistry and Chemistry Toronto Ontario M5S 1A8 Canada
  • Dmitry M. Korzhnev, The University of Toronto Departments of Molecular Genetics, Biochemistry and Chemistry Toronto Ontario M5S 1A8 Canada
  • Philipp Neudecker, The University of Toronto Departments of Molecular Genetics, Biochemistry and Chemistry Toronto Ontario M5S 1A8 Canada
  • D. Flemming Hansen, The University of Toronto Departments of Molecular Genetics, Biochemistry and Chemistry Toronto Ontario M5S 1A8 Canada
  • Matthew H. J. Cordes, The University of Arizona Department of Chemistry and Biochemistry Tucson AZ 85721-0088 USA
  • Lewis E. Kay, The University of Toronto Departments of Molecular Genetics, Biochemistry and Chemistry Toronto Ontario M5S 1A8 Canada

• • Journal Journal of Biomolecular NMR
  • Online ISSN 1573-5001
  • Print ISSN 0925-2738
  • Journal Volume Volume 47
  • Journal Issue Volume 47, Number 2

Source: Journal of Biomolecular NMR