Abstract
Cholesterol and alpha-tocopherol (vitamin E) are important constituents of cell membranes having similar molecular shapes and sizes. These two molecules, however, exhibit very different properties in membranes and are thought to play different roles in the biology of the cell. Cholesterol is found in high concentrations in membranes, especially those composed of saturated phospholipids such as 1,2-dipalmitoyl-sn-glycero-3-phosphocholine (DPPC), while recent experiments suggest that alpha-tocopherol, which is typically found in much smaller concentrations, preferentially accumulates in membranes containing highly polyunsaturated lipids such as 1-stearoyl-2-docosahexaenoyl-sn-glycero-3-phosphocholine (SDPC). Here we examine the structural and dynamic properties of alpha-tocopherol and cholesterol and their effects on phospholipid bilayers using molecular dynamics (MD) computer simulation methods. Six long simulations (hundreds of nanosecond each) have been carried out, one for each neat lipid (DPPC and SDPC), and one for each solute in each lipid. The dramatically different effect on membrane properties that is observed in the simulation is explained in terms of unique solute-lipid interactions arising from polyunsaturation of the lipid acyl chains.
Published Version (
Free)
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call