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Hydration Dynamics of a Halophilic Protein in Folded and Unfolded States

Qvist, Johan LU ; Ortega, Gabriel; Tadeo, Xavier; Millet, Oscar and Halle, Bertil LU (2012) In The Journal of Physical Chemistry Part B 116(10). p.3436-3444
Abstract
Proteins from halophilic microorganisms thriving at high salinity have an excess of charged carboxylate groups, and it is widely believed that this gives rise to an exceptionally strong hydration that stabilizes these proteins against unfolding and aggregation. Here, we examine this hypothesis by characterizing the hydration dynamics of a halophilic model protein with frequency- and temperature-dependent O-17 magnetic relaxation. The halophilic protein Kx6E was constructed by replacing six lysine residues with glutamate residues in the IgG binding domain of protein L. We also studied the unfolded form of Kx6E in the absence of salt. We find that the hydration dynamics of Kx6E does not differ from protein L or from other previously studied... (More)
Proteins from halophilic microorganisms thriving at high salinity have an excess of charged carboxylate groups, and it is widely believed that this gives rise to an exceptionally strong hydration that stabilizes these proteins against unfolding and aggregation. Here, we examine this hypothesis by characterizing the hydration dynamics of a halophilic model protein with frequency- and temperature-dependent O-17 magnetic relaxation. The halophilic protein Kx6E was constructed by replacing six lysine residues with glutamate residues in the IgG binding domain of protein L. We also studied the unfolded form of Kx6E in the absence of salt. We find that the hydration dynamics of Kx6E does not differ from protein L or from other previously studied mesophilic proteins. This finding challenges the hypothesis of exceptional hydration for halophilic proteins. The unfolded form of Kx6E is found to be expanded, with a weaker dynamical perturbation of the hydration water than for folded proteins. (Less)
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author
organization
publishing date
type
Contribution to journal
publication status
published
subject
in
The Journal of Physical Chemistry Part B
volume
116
issue
10
pages
3436 - 3444
publisher
The American Chemical Society
external identifiers
  • wos:000301509500041
  • scopus:84858317534
ISSN
1520-5207
DOI
10.1021/jp3000569
language
English
LU publication?
yes
id
4988d242-d808-48e2-9345-6f45df432542 (old id 2591133)
date added to LUP
2012-05-30 14:43:00
date last changed
2017-09-03 04:21:33
@article{4988d242-d808-48e2-9345-6f45df432542,
  abstract     = {Proteins from halophilic microorganisms thriving at high salinity have an excess of charged carboxylate groups, and it is widely believed that this gives rise to an exceptionally strong hydration that stabilizes these proteins against unfolding and aggregation. Here, we examine this hypothesis by characterizing the hydration dynamics of a halophilic model protein with frequency- and temperature-dependent O-17 magnetic relaxation. The halophilic protein Kx6E was constructed by replacing six lysine residues with glutamate residues in the IgG binding domain of protein L. We also studied the unfolded form of Kx6E in the absence of salt. We find that the hydration dynamics of Kx6E does not differ from protein L or from other previously studied mesophilic proteins. This finding challenges the hypothesis of exceptional hydration for halophilic proteins. The unfolded form of Kx6E is found to be expanded, with a weaker dynamical perturbation of the hydration water than for folded proteins.},
  author       = {Qvist, Johan and Ortega, Gabriel and Tadeo, Xavier and Millet, Oscar and Halle, Bertil},
  issn         = {1520-5207},
  language     = {eng},
  number       = {10},
  pages        = {3436--3444},
  publisher    = {The American Chemical Society},
  series       = {The Journal of Physical Chemistry Part B},
  title        = {Hydration Dynamics of a Halophilic Protein in Folded and Unfolded States},
  url          = {http://dx.doi.org/10.1021/jp3000569},
  volume       = {116},
  year         = {2012},
}