Saturation with cholesterol increases vertical order and smoothes the surface of the phosphatidylcholine bilayer: A molecular simulation study

► POPC and POPC-Cholesterol (1:1 molar ratio) bilayers were MD simulated for 200 ns each. ► Distributions of vertical positions of POPC and cholesterol atoms were calculated. ► Cholesterol significantly narrows the distribution of vertical positions of each of the lipid atoms. ► The surface of the POPC bilayer saturated with cholesterol is smoother than of the POPC bilayer without cholesterol.