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Title: High-throughput simulations reveal membrane-mediated effects of alcohols on MscL gating

Abstract

The mechanosensitive channels of large conductance (MscL) are bacterial membrane proteins that serve as last resort emergency release valves in case of severe osmotic downshock. Sensing bilayer tension, MscL channels are sensitive to changes in the bilayer environment and are, therefore, an ideal test case for exploring membrane protein coupling. Here, we use high-throughput coarse-grained molecular dynamics simulations to characterize MscL gating kinetics in different bilayer environments under the influence of alcohols. We performed over five hundred simulations to obtain sufficient statistics to reveal the subtle effects of changes in the membrane environment on MscL gating. MscL opening times were found to increase with the addition of the straight-chain alcohols ethanol, octanol, and to some extent dodecanol but not with hexadecanol. Increasing concentration of octanol increased the impeding effect, but only up to 10–20 mol %. Our in silico predictions were experimentally confirmed using reconstituted MscL in a liposomal fluorescent efflux assay. Our combined data reveal that the effect of alcohols on MscL gating arises not through specific binding sites but through a combination of the alcohol-induced changes to a number of bilayer properties and their alteration of the MscL–bilayer interface. Finally, our work provides a key example of howmore » extensive molecular simulations can be used to predict the functional modification of membrane proteins by subtle changes in their bilayer environment.« less

Authors:
 [1];  [1];  [1];  [1];  [1];  [1];  [1];  [1]; ORCiD logo [2]
  1. Univ. of Groningen, Groningen (The Netherlands)
  2. Univ. of Groningen, Groningen (The Netherlands); Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)
Publication Date:
Research Org.:
Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)
Sponsoring Org.:
USDOE
OSTI Identifier:
1346131
Report Number(s):
LLNL-JRNL-715277
Journal ID: ISSN 0002-7863
Grant/Contract Number:
AC52-07NA27344
Resource Type:
Journal Article: Accepted Manuscript
Journal Name:
Journal of the American Chemical Society
Additional Journal Information:
Journal Volume: 139; Journal Issue: 7; Journal ID: ISSN 0002-7863
Publisher:
American Chemical Society (ACS)
Country of Publication:
United States
Language:
English
Subject:
59 BASIC BIOLOGICAL SCIENCES

Citation Formats

Melo, Manuel N., Arnarez, Clement, Sikkema, Hendrik, Kumar, Neeraj, Walko, Martin, Berendsen, Herman J. C., Kocer, Armagan, Marrink, Siewert J., and Ingolfsson, Helgi I. High-throughput simulations reveal membrane-mediated effects of alcohols on MscL gating. United States: N. p., 2017. Web. doi:10.1021/jacs.6b11091.
Melo, Manuel N., Arnarez, Clement, Sikkema, Hendrik, Kumar, Neeraj, Walko, Martin, Berendsen, Herman J. C., Kocer, Armagan, Marrink, Siewert J., & Ingolfsson, Helgi I. High-throughput simulations reveal membrane-mediated effects of alcohols on MscL gating. United States. doi:10.1021/jacs.6b11091.
Melo, Manuel N., Arnarez, Clement, Sikkema, Hendrik, Kumar, Neeraj, Walko, Martin, Berendsen, Herman J. C., Kocer, Armagan, Marrink, Siewert J., and Ingolfsson, Helgi I. Thu . "High-throughput simulations reveal membrane-mediated effects of alcohols on MscL gating". United States. doi:10.1021/jacs.6b11091. https://www.osti.gov/servlets/purl/1346131.
@article{osti_1346131,
title = {High-throughput simulations reveal membrane-mediated effects of alcohols on MscL gating},
author = {Melo, Manuel N. and Arnarez, Clement and Sikkema, Hendrik and Kumar, Neeraj and Walko, Martin and Berendsen, Herman J. C. and Kocer, Armagan and Marrink, Siewert J. and Ingolfsson, Helgi I.},
abstractNote = {The mechanosensitive channels of large conductance (MscL) are bacterial membrane proteins that serve as last resort emergency release valves in case of severe osmotic downshock. Sensing bilayer tension, MscL channels are sensitive to changes in the bilayer environment and are, therefore, an ideal test case for exploring membrane protein coupling. Here, we use high-throughput coarse-grained molecular dynamics simulations to characterize MscL gating kinetics in different bilayer environments under the influence of alcohols. We performed over five hundred simulations to obtain sufficient statistics to reveal the subtle effects of changes in the membrane environment on MscL gating. MscL opening times were found to increase with the addition of the straight-chain alcohols ethanol, octanol, and to some extent dodecanol but not with hexadecanol. Increasing concentration of octanol increased the impeding effect, but only up to 10–20 mol %. Our in silico predictions were experimentally confirmed using reconstituted MscL in a liposomal fluorescent efflux assay. Our combined data reveal that the effect of alcohols on MscL gating arises not through specific binding sites but through a combination of the alcohol-induced changes to a number of bilayer properties and their alteration of the MscL–bilayer interface. Finally, our work provides a key example of how extensive molecular simulations can be used to predict the functional modification of membrane proteins by subtle changes in their bilayer environment.},
doi = {10.1021/jacs.6b11091},
journal = {Journal of the American Chemical Society},
number = 7,
volume = 139,
place = {United States},
year = {Thu Jan 26 00:00:00 EST 2017},
month = {Thu Jan 26 00:00:00 EST 2017}
}

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