Predicted Decrease in Membrane Oxygen Permeability with Addition of Cholesterol.

Aberrations in cholesterol homeostasis are associated with several diseases that can be linked to changes in cellular oxygen usage. Prior biological and physical studies have suggested that membrane cholesterol content can modulate oxygen delivery, but questions of magnitude and biological significance remain open for further investigation. Here, we use molecular dynamics simulations in a first step toward reexamining the rate impact of cholesterol on the permeation of oxygen through phospholipid bilayers. The simulation models are closely compared with published electron paramagnetic resonance (EPR) oximetry measurements. The simulations predict an oxygen permeability reduction due to cholesterol but also suggest that the EPR experiments may have underestimated resistance to oxygen permeation in the phospholipid headgroup region.