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Protein conformational exchange measured by (1)H R 1ρ relaxation dispersion of methyl groups.

Weininger, Ulrich LU ; Blissing, Annica T; Hennig, Janosch; Ahlner, Alexandra; Liu, Zhihong; Vogel, Hans; Akke, Mikael LU and Lundström, Patrik (2013) In Journal of Biomolecular NMR 57(1). p.47-55
Abstract
Activated dynamics plays a central role in protein function, where transitions between distinct conformations often underlie the switching between active and inactive states. The characteristic time scales of these transitions typically fall in the microsecond to millisecond range, which is amenable to investigations by NMR relaxation dispersion experiments. Processes at the faster end of this range are more challenging to study, because higher RF field strengths are required to achieve refocusing of the exchanging magnetization. Here we describe a rotating-frame relaxation dispersion experiment for (1)H spins in methyl (13)CHD2 groups, which improves the characterization of fast exchange processes. The influence of (1)H-(1)H... (More)
Activated dynamics plays a central role in protein function, where transitions between distinct conformations often underlie the switching between active and inactive states. The characteristic time scales of these transitions typically fall in the microsecond to millisecond range, which is amenable to investigations by NMR relaxation dispersion experiments. Processes at the faster end of this range are more challenging to study, because higher RF field strengths are required to achieve refocusing of the exchanging magnetization. Here we describe a rotating-frame relaxation dispersion experiment for (1)H spins in methyl (13)CHD2 groups, which improves the characterization of fast exchange processes. The influence of (1)H-(1)H rotating-frame nuclear Overhauser effects (ROE) is shown to be negligible, based on a comparison of R 1ρ relaxation data acquired with tilt angles of 90° and 35°, in which the ROE is maximal and minimal, respectively, and on samples containing different (1)H densities surrounding the monitored methyl groups. The method was applied to ubiquitin and the apo form of calmodulin. We find that ubiquitin does not exhibit any (1)H relaxation dispersion of its methyl groups at 10 or 25 °C. By contrast, calmodulin shows significant conformational exchange of the methionine methyl groups in its C-terminal domain, as previously demonstrated by (1)H and (13)C CPMG experiments. The present R 1ρ experiment extends the relaxation dispersion profile towards higher refocusing frequencies, which improves the definition of the exchange correlation time, compared to previous results. (Less)
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author
organization
publishing date
type
Contribution to journal
publication status
published
subject
in
Journal of Biomolecular NMR
volume
57
issue
1
pages
47 - 55
publisher
Springer
external identifiers
  • wos:000323673800006
  • pmid:23904100
  • scopus:84883554536
ISSN
1573-5001
DOI
10.1007/s10858-013-9764-4
language
English
LU publication?
yes
id
80f7ab9c-1bee-46c0-bd95-66e58545455f (old id 4006315)
date added to LUP
2013-09-09 12:03:16
date last changed
2019-02-27 01:22:06
@article{80f7ab9c-1bee-46c0-bd95-66e58545455f,
  abstract     = {Activated dynamics plays a central role in protein function, where transitions between distinct conformations often underlie the switching between active and inactive states. The characteristic time scales of these transitions typically fall in the microsecond to millisecond range, which is amenable to investigations by NMR relaxation dispersion experiments. Processes at the faster end of this range are more challenging to study, because higher RF field strengths are required to achieve refocusing of the exchanging magnetization. Here we describe a rotating-frame relaxation dispersion experiment for (1)H spins in methyl (13)CHD2 groups, which improves the characterization of fast exchange processes. The influence of (1)H-(1)H rotating-frame nuclear Overhauser effects (ROE) is shown to be negligible, based on a comparison of R 1ρ relaxation data acquired with tilt angles of 90° and 35°, in which the ROE is maximal and minimal, respectively, and on samples containing different (1)H densities surrounding the monitored methyl groups. The method was applied to ubiquitin and the apo form of calmodulin. We find that ubiquitin does not exhibit any (1)H relaxation dispersion of its methyl groups at 10 or 25 °C. By contrast, calmodulin shows significant conformational exchange of the methionine methyl groups in its C-terminal domain, as previously demonstrated by (1)H and (13)C CPMG experiments. The present R 1ρ experiment extends the relaxation dispersion profile towards higher refocusing frequencies, which improves the definition of the exchange correlation time, compared to previous results.},
  author       = {Weininger, Ulrich and Blissing, Annica T and Hennig, Janosch and Ahlner, Alexandra and Liu, Zhihong and Vogel, Hans and Akke, Mikael and Lundström, Patrik},
  issn         = {1573-5001},
  language     = {eng},
  number       = {1},
  pages        = {47--55},
  publisher    = {Springer},
  series       = {Journal of Biomolecular NMR},
  title        = {Protein conformational exchange measured by (1)H R 1ρ relaxation dispersion of methyl groups.},
  url          = {http://dx.doi.org/10.1007/s10858-013-9764-4},
  volume       = {57},
  year         = {2013},
}