Description: Neutron scattering reveals extremely slow cell water in a Dead Sea organism

This title appears in the Scientific Report : 2007

Neutron scattering reveals extremely slow cell water in a Dead Sea organism

Intracellular water dynamics in Haloarcula marismortui, an extremely halophilic organism originally isolated from the Dead Sea, was studied by neutron scattering. The water in centrifuged cell pellets was examined by means of two spectrometers, IN6 and IN16, sensitive to motions with time scales of...

Personal Name(s):	Tehei, M.
	Franzetti, B. / Wood, K. / Gabel, F. / Fabiani, E. / Jasnin, M. / Zamponi, M. / Oesterhelt, D. / Zaccai, G. / Ginzburg, M. / Ginzburg, B. Z.
Contributing Institute:	JCNS; JCNS Streumethoden; IFF-4 Neutronenstreuung; IFF-5
Published in:	Proceedings of the National Academy of Sciences of the United States of America, 104 (2007) S. 766 - 771
Imprint:	Washington, DC Academy 2007
Physical Description:	766 - 771
PubMed ID:	17215355
DOI:	10.1073/pnas.0601639104
Document Type:	Journal Article
Research Program:	Großgeräte für die Forschung mit Photonen, Neutronen und Ionen (PNI) Kondensierte Materie
Series Title:	Proceedings of the National Academy of Sciences of the United States of America 104
Subject (ZB):	Escherichia coli Haloarcula marismortui: cytology Intracellular Fluid: chemistry Israel Jordan Neutron Diffraction Neutrons Oceans and Seas Potassium Chloride Sodium Chloride Solutions Spectrum Analysis Time Factors Water: analysis Water: chemistry Water J Haloarcula marismortui water structure and dynamics extreme haplophile
	Publikationsportal JuSER

Please use the identifier: http://dx.doi.org/10.1073/pnas.0601639104 in citations.

Intracellular water dynamics in Haloarcula marismortui, an extremely halophilic organism originally isolated from the Dead Sea, was studied by neutron scattering. The water in centrifuged cell pellets was examined by means of two spectrometers, IN6 and IN16, sensitive to motions with time scales of 10 ps and 1 ns, respectively. From IN6 data, a translational diffusion constant of 1.3 x 10(-5) cm(2) s(-1) was determined at 285 K. This value is close to that found previously for other cells and close to that for bulk water, as well as that of the water in the 3.5 M NaCl solution bathing the cells. A very slow water component was discovered from the IN16 data. At 285 K the water-protons of this component displays a residence time of 411 ps (compared with a few ps in bulk water). At 300 K, the residence time dropped to 243 ps and was associated with a translational diffusion of 9.3 x 10(-8) cm(2) s(-1), or 250 times lower than that of bulk water. This slow water accounts for approximately 76% of cell water in H. marismortui. No such water was found in Escherichia coli measured on BSS, a neutron spectrometer with properties similar to those of IN16. It is hypothesized that the slow mobility of a large part of H. marismortui cell water indicates a specific water structure responsible for the large amounts of K(+) bound within these extremophile cells.