BIOPHYSICAL THEORY AND MODELING |
The effect of trehalose on a phospholipid membrane under mechanical stress
Cristina S. Pereira 1 and Philippe H. Hunenberger 1*
1 ETH-Zurich
* To whom correspondence should be addressed. E-mail: phil{at}igc.phys.chem.ethz.ch.
Submitted on February 19, 2008
Revised on March 25, 2008
Accepted on 5 May 2008
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Abstract |
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Explicit-solvent molecular dynamics simulations are used to investigate at atomic resolution the effect of trehalose on a hydrated phospholipid bilayer under mechanical stress (stretching forces imposed in the form of negative lateral pressure). Simulations are carried out in the absence or in the presence of trehalose at 325 K and with different values for the negative lateral pressure. In the concentration regime (2 molal) and range of lateral pressures (1 to -250 bar) investigated, trehalose is found to interact directly with the membrane, partially replacing water molecules in the formation of hydrogen bonds with the lipid headgroups. Similar to previous findings in the context of thermal stress, the number, degree of bridging and reaching depth of these hydrogen bonds increases with the magnitude of the perturbation. However, at the concentration considered trehalose is not sufficient to preserve the integrity of the membrane structure and to prevent its extreme elongation (and possible disruption) under the effect of stretching forces.
Key Words:
DPPC, molecular dynamics, phospholipid membrane, surface tension, trehalose
