The physical state of water in bacterial spores.
(2009) In Proceedings of the National Academy of Sciences 106(46). p.19334-19339- Abstract
- The bacterial spore, the hardiest known life form, can survive in a metabolically dormant state for many years and can withstand high temperatures, radiation, and toxic chemicals. The molecular basis of spore dormancy and resistance is not understood, but the physical state of water in the different spore compartments is thought to play a key role. To characterize this water in situ, we recorded the water 2H and 17O spin relaxation rates in D2O-exchanged Bacillus subtilis spores over a wide frequency range. The data indicate high water mobility throughout the spore, comparable with binary protein–water systems at similar hydration levels. Even in the dense core, the average water rotational correlation time is only 50 ps. Spore dormancy... (More)
- The bacterial spore, the hardiest known life form, can survive in a metabolically dormant state for many years and can withstand high temperatures, radiation, and toxic chemicals. The molecular basis of spore dormancy and resistance is not understood, but the physical state of water in the different spore compartments is thought to play a key role. To characterize this water in situ, we recorded the water 2H and 17O spin relaxation rates in D2O-exchanged Bacillus subtilis spores over a wide frequency range. The data indicate high water mobility throughout the spore, comparable with binary protein–water systems at similar hydration levels. Even in the dense core, the average water rotational correlation time is only 50 ps. Spore dormancy therefore cannot be explained by glass-like quenching of molecular diffusion but may be linked to dehydration-induced conformational changes in key enzymes. The data demonstrate that most spore proteins are rotationally immobilized, which may contribute to heat resistance by preventing heat-denatured proteins from aggregating irreversibly. We also find that the water permeability of the inner membrane is at least 2 orders of magnitude lower than for model membranes, consistent with the reported high degree of lipid immobilization in this membrane and with its proposed role in spore resistance to chemicals that damage DNA. The quantitative results reported here on water mobility and transport provide important clues about the mechanism of spore dormancy and resistance, with relevance to food preservation, disease prevention, and astrobiology. (Less)
Please use this url to cite or link to this publication:
https://lup.lub.lu.se/record/1502424
- author
- Persson Sunde, Erik LU ; Setlow, Peter ; Hederstedt, Lars LU and Halle, Bertil LU
- organization
- publishing date
- 2009
- type
- Contribution to journal
- publication status
- published
- subject
- in
- Proceedings of the National Academy of Sciences
- volume
- 106
- issue
- 46
- pages
- 19334 - 19339
- publisher
- National Academy of Sciences
- external identifiers
-
- wos:000271907400022
- scopus:73349109182
- ISSN
- 1091-6490
- DOI
- 10.1073/pnas.0908712106
- language
- English
- LU publication?
- yes
- id
- 6b8d9a52-239a-43f7-a742-2155453d2a57 (old id 1502424)
- date added to LUP
- 2016-04-01 11:42:26
- date last changed
- 2022-04-20 20:35:58
@article{6b8d9a52-239a-43f7-a742-2155453d2a57,
abstract = {{The bacterial spore, the hardiest known life form, can survive in a metabolically dormant state for many years and can withstand high temperatures, radiation, and toxic chemicals. The molecular basis of spore dormancy and resistance is not understood, but the physical state of water in the different spore compartments is thought to play a key role. To characterize this water in situ, we recorded the water 2H and 17O spin relaxation rates in D2O-exchanged Bacillus subtilis spores over a wide frequency range. The data indicate high water mobility throughout the spore, comparable with binary protein–water systems at similar hydration levels. Even in the dense core, the average water rotational correlation time is only 50 ps. Spore dormancy therefore cannot be explained by glass-like quenching of molecular diffusion but may be linked to dehydration-induced conformational changes in key enzymes. The data demonstrate that most spore proteins are rotationally immobilized, which may contribute to heat resistance by preventing heat-denatured proteins from aggregating irreversibly. We also find that the water permeability of the inner membrane is at least 2 orders of magnitude lower than for model membranes, consistent with the reported high degree of lipid immobilization in this membrane and with its proposed role in spore resistance to chemicals that damage DNA. The quantitative results reported here on water mobility and transport provide important clues about the mechanism of spore dormancy and resistance, with relevance to food preservation, disease prevention, and astrobiology.}},
author = {{Persson Sunde, Erik and Setlow, Peter and Hederstedt, Lars and Halle, Bertil}},
issn = {{1091-6490}},
language = {{eng}},
number = {{46}},
pages = {{19334--19339}},
publisher = {{National Academy of Sciences}},
series = {{Proceedings of the National Academy of Sciences}},
title = {{The physical state of water in bacterial spores.}},
url = {{http://dx.doi.org/10.1073/pnas.0908712106}},
doi = {{10.1073/pnas.0908712106}},
volume = {{106}},
year = {{2009}},
}