Effect of high hydrostatic pressure on the bacterial mechanosensitive channel MscS

Macdonald, A. G. and Martinac, B. (2005) Effect of high hydrostatic pressure on the bacterial mechanosensitive channel MscS. European Biophysics Journal, 34 5: 434-441. doi:10.1007/s00249-005-0478-8


Author Macdonald, A. G.
Martinac, B.
Title Effect of high hydrostatic pressure on the bacterial mechanosensitive channel MscS
Journal name European Biophysics Journal   Check publisher's open access policy
ISSN 0175-7571
1432-1017
Publication date 2005-07-01
Sub-type Article (original research)
DOI 10.1007/s00249-005-0478-8
Volume 34
Issue 5
Start page 434
End page 441
Total pages 8
Place of publication Heidelberg, Germany
Publisher Springer
Language eng
Abstract We have investigated the effect of high hydrostatic pressure on MscS, the bacterial mechanosensitive channel of small conductance. Pressure affected channel kinetics but not conductance. At negative pipette voltages (corresponding to membrane depolarization in the inside-out patch configuration used in our experiments) the channel exhibited a reversible reduction in activity with increasing hydrostatic pressure between 0 and 900 atm (90 MPa) at 23 degrees C. The reduced activity was characterized by a significant reduction in the channel opening probability resulting from a shortening of the channel openings with increasing pressure. Thus high hydrostatic pressure generally favoured channel closing. Cooling the patch by approximately 10 degrees C, intended to order the bilayer component of the patch by an amount similar to that caused by 50 MPa at 23 degrees C, had relatively little effect. This implies that pressure does not affect channel kinetics via bilayer order. Accordingly we postulate that lateral compression of the bilayer, under high hydrostatic pressure, is responsible. These observations also have implications for our understanding of the adaptation of mechanosensitive channels in deep-sea bacteria.
Keyword Ion channels
Mechanosensitivity
Bacteria
Patch clamp
Hydrostatic pressure
Q-Index Code C1
Q-Index Status Provisional Code
Institutional Status UQ
Additional Notes A Proceeding of the 28th Annual Meeting of the Australian Society for Biophysics.

Document type: Journal Article
Sub-type: Article (original research)
Collections: Excellence in Research Australia (ERA) - Collection
School of Biomedical Sciences Publications
 
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Created: Thu, 20 Sep 2007, 04:08:50 EST