Cell water dynamics on multiple time scales
(2008) In Proceedings of the National Academy of Sciences 105(17). p.6266-6271- Abstract
- Water–biomolecule interactions have been extensively studied in dilute solutions, crystals, and rehydrated powders, but none of these model systems may capture the behavior of water in the highly organized intracellular milieu. Because of the experimental difficulty of selectively probing the structure and dynamics of water in intact cells, radically different views about the properties of cell water have proliferated. To resolve this long-standing controversy, we have measured the 2H spin relaxation rate in living bacteria cultured in D2O. The relaxation data, acquired in a wide magnetic field range (0.2 mT–12 T) and analyzed in a model-independent way, reveal water dynamics on a wide range of time scales. Contradicting the view that a... (More)
- Water–biomolecule interactions have been extensively studied in dilute solutions, crystals, and rehydrated powders, but none of these model systems may capture the behavior of water in the highly organized intracellular milieu. Because of the experimental difficulty of selectively probing the structure and dynamics of water in intact cells, radically different views about the properties of cell water have proliferated. To resolve this long-standing controversy, we have measured the 2H spin relaxation rate in living bacteria cultured in D2O. The relaxation data, acquired in a wide magnetic field range (0.2 mT–12 T) and analyzed in a model-independent way, reveal water dynamics on a wide range of time scales. Contradicting the view that a substantial fraction of cell water is strongly perturbed, we find that ≈85% of cell water in Escherichia coli and in the extreme halophile Haloarcula marismortui has bulk-like dynamics. The remaining ≈15% of cell water interacts directly with biomolecular surfaces and is motionally retarded by a factor 15 ± 3 on average, corresponding to a rotational correlation time of 27 ps. This dynamic perturbation is three times larger than for small monomeric proteins in solution, a difference we attribute to secluded surface hydration sites in supramolecular assemblies. The relaxation data also show that a small fraction (≈0.1%) of cell water exchanges from buried hydration sites on the microsecond time scale, consistent with the current understanding of protein hydration in solutions and crystals. (Less)
Please use this url to cite or link to this publication:
https://lup.lub.lu.se/record/1227838
- author
- Persson Sunde, Erik LU and Halle, Bertil LU
- organization
- publishing date
- 2008
- type
- Contribution to journal
- publication status
- published
- subject
- keywords
- Haloarcula marismortui, in vivo NMR, buried water molecules, Escherichia coli, biomolecular hydration
- in
- Proceedings of the National Academy of Sciences
- volume
- 105
- issue
- 17
- pages
- 6266 - 6271
- publisher
- National Academy of Sciences
- external identifiers
-
- wos:000255534100012
- scopus:44049105071
- ISSN
- 1091-6490
- DOI
- 10.1073/pnas.0709585105
- language
- English
- LU publication?
- yes
- id
- 26098097-d856-4b65-a12d-417f398f242b (old id 1227838)
- date added to LUP
- 2016-04-01 12:04:31
- date last changed
- 2022-04-29 00:17:55
@article{26098097-d856-4b65-a12d-417f398f242b,
abstract = {{Water–biomolecule interactions have been extensively studied in dilute solutions, crystals, and rehydrated powders, but none of these model systems may capture the behavior of water in the highly organized intracellular milieu. Because of the experimental difficulty of selectively probing the structure and dynamics of water in intact cells, radically different views about the properties of cell water have proliferated. To resolve this long-standing controversy, we have measured the 2H spin relaxation rate in living bacteria cultured in D2O. The relaxation data, acquired in a wide magnetic field range (0.2 mT–12 T) and analyzed in a model-independent way, reveal water dynamics on a wide range of time scales. Contradicting the view that a substantial fraction of cell water is strongly perturbed, we find that ≈85% of cell water in Escherichia coli and in the extreme halophile Haloarcula marismortui has bulk-like dynamics. The remaining ≈15% of cell water interacts directly with biomolecular surfaces and is motionally retarded by a factor 15 ± 3 on average, corresponding to a rotational correlation time of 27 ps. This dynamic perturbation is three times larger than for small monomeric proteins in solution, a difference we attribute to secluded surface hydration sites in supramolecular assemblies. The relaxation data also show that a small fraction (≈0.1%) of cell water exchanges from buried hydration sites on the microsecond time scale, consistent with the current understanding of protein hydration in solutions and crystals.}},
author = {{Persson Sunde, Erik and Halle, Bertil}},
issn = {{1091-6490}},
keywords = {{Haloarcula marismortui; in vivo NMR; buried water molecules; Escherichia coli; biomolecular hydration}},
language = {{eng}},
number = {{17}},
pages = {{6266--6271}},
publisher = {{National Academy of Sciences}},
series = {{Proceedings of the National Academy of Sciences}},
title = {{Cell water dynamics on multiple time scales}},
url = {{http://dx.doi.org/10.1073/pnas.0709585105}},
doi = {{10.1073/pnas.0709585105}},
volume = {{105}},
year = {{2008}},
}