Replacing the cholesterol hydroxyl group with the ketone group facilitates sterol flip-flop and promotes membrane fluidity.

The 3alpha-hydroxyl group is a characteristic structural element of all membrane sterol molecules, while the 3-ketone group is more typically found in steroid hormones. In this work, we investigate the effect of substituting the hydroxyl group in cholesterol with the ketone group to produce ketosterone. Extensive atomistic molecular dynamics simulations of saturated lipid membranes with either cholesterol or ketosterone show that, like cholesterol, ketosterone increases membrane order and induces condensation.

Stearic acid spin labels in lipid bilayers: insight through atomistic simulations.

Spin-labeled stearic acid species are commonly used for electron paramagnetic resonance (EPR) studies of cell membranes to investigate phase transitions, fluidity, and other physical properties. In this paper, we use large-scale molecular dynamics simulations to investigate the position and behavior of nitroxide spin labels attached to stearic acid molecules in dipalmitoylphosphatidylcholine (DPPC) bilayers. The results of these studies are potentially very important for the interpretation of EPR spectra, which rely on assumptions about the position of the label in the membrane.

Exploring the effect of xenon on biomembranes.

We report the initial findings of 100 ns molecular dynamics simulations of the role of cellular membranes in general anaesthesia. The effect of xenon on hydrated dipalmitoylphosphatidylcholine bilayers is described. The xenon atoms were found to prefer the interfacial and central regions of the bilayer.

Coarse-grained simulation studies of a liquid crystal dendrimer: towards computational predictions of nanoscale structure through microphase separation.

Coarse-grained simulations are described in which the behaviour of a system of model liquid crystalline dendrimer molecules is studied in both liquid and smectic-A liquid crystalline phases. The model system is based on a third generation carbosilane dendrimer, which is functionalised at the surface by short polymeric chains terminated in mesogenic units. The design of the coarse-grained model is based on initial Monte Carlo studies of a single carbosilane molecule at an atomistic level, which yield structural data.

Molecular dynamics simulations of side chain liquid crystal polymer molecules in isotropic and liquid-crystalline melts.

A detailed molecular dynamics simulation study is described for a polysiloxane side chain liquid crystal polymer (SCLCP). The simulations use a coarse-grained model composed of a combination of isotropic and anisotropic interaction sites. On cooling from a fully isotropic polymer melt, we see spontaneous microphase separation into polymer-rich and mesogen-rich regions.