Effects of hydrostatic pressure on lipid bilayer membranes. I. Influence on membrane thickness and activation volumes of lipophilic ion transport (original) (raw)

The effect of hydrostatic pressure on S-layer-supported lipid membranes

Biochimica et Biophysica Acta (BBA) - Biomembranes, 2002

We report on the behavior of unsupported and surface layer (S-layer)-supported lipid membranes at the application of a uniform hydrostatic pressure. At a hydrostatic pressure gradient higher than 6 N/m 2 , unsupported lipid membranes, independent from which side pressurized and S-layer-supported lipid membranes pressurized from the lipid-faced side revealed a pronounced increase in capacitance. A maximal hydrostatic pressure gradient of 11.0 N/m 2 resulted in an almost doubling of the capacitance of the (composite) membranes. S-layer-supported lipid membranes showed a hysteresis in the capacitance versus pressure plot, indicating that this composite structure required a certain time to reorient when the pressure gradient acting from the lipid-faced side was balanced. By contrast, the S-layer-supported lipid membrane pressurized from the protein-faced side revealed only a minute increase in capacitance (C/C 0,max = 1.17 F 0.05), reflecting only minor pressure-induced area expansion. In addition, no hysteresis could be observed, indicating that no rearrangement of the composite membrane occurred. The maximal induced tension was with 4.3 F 0.2 mN/m, significantly higher than that of unsupported (2.5 F 0.3 mN/m) and Slayer-supported lipid membranes pressurized from the lipid-faced side (2.6 F 0.1 mN/m). D

Pressure effects on lipid membrane structure and dynamics

Chemistry and Physics of Lipids, 2011

The effect of hydrostatic pressure on lipid structure and dynamics is highly important as a tool in biophysics and bio-technology, and in the biology of deep sea organisms. Despite its importance, high hydrostatic pressure remains significantly less utilised than other thermodynamic variables such as temperature and chemical composition. Here, we give an overview of some of the theoretical aspects which determine lipid behaviour under pressure and the techniques and technology available to study these effects. We also summarise several recent experiments which highlight the information available from these approaches.

The Influence of 1-Alkanols and External Pressure on the Lateral Pressure Profiles of Lipid Bilayers

Biophysical Journal, 2008

The suggestion by Robert Cantor, that drug-induced pressure changes in lipid bilayers can change the conformational equilibrium between open and closed states of membrane proteins and thereby cause anesthesia, attracted much attention lately. Here, we studied the effect of both large external pressure and of 1-alkanols of different chain lengths-some of them anesthetics, others not-on the lateral pressure profiles across dimyristoylphosphatidylcholine (DMPC) bilayers by molecular dynamics simulations. For a pure DMPC bilayer, high pressure both reduced and broadened the tension at the interface hydrophobic/hydrophilic and diminished the repulsion between the phospholipid headgroups. Whereas the effect of ethanol on the lateral pressure profile was similar to the effect of a large external pressure on a DMPC bilayer, long-chain 1-alkanols significantly amplified local maxima and minima in the lateral pressure profile. For most 1-alkanols, external pressure had moderate effects and did not reverse the changes 1-alkanols exerted on the pressure profile. Nevertheless, assuming the bent helix model as a simple geometric model for the transmembrane region of a membrane protein, protein conformational equilibria were shifted in opposite directions by addition of 1-alkanols and additional application of external pressure.

High hydrostatic pressure and the cell membrane

Annals of the New York Academy of Sciences, 2010

The brewing and baking yeast Saccharomyces cerevisiae is a useful eukaryotic model of stress response systems whose study could lead to the understanding of stress response mechanisms in other organisms. High hydrostatic pressure (HHP) exerts broad effects upon yeast cells, interfering with cell membranes, cellular architecture, and the processes of polymerization and denaturation of proteins. In this review, we focus on the effect of HHP on the S. cerevisiae cell membrane and describe the main signaling pathways involved in the pressure response.