Cholesterol influence on the bending elasticity of lipid membranes

The influence of cholesterol on the bending elasticity of lipid membranes from 1-stearoyl-2-oleoyl-sn-glycero-3-phosphocholine (SOPC) was studied. We used the analysis of thermally induced shape fluctuations of giant nearly-spherical lipid vesicles for the determination of the bending elastic modulus. atively low concentrations (<10 mol %) of cholesterol in the SOPC membrane the bending elasticity modulus first increases with about 30% upon cholesterol increase and after that decreases to a value slightly lower than that of the pure bilayer. The increase of the cholesterol from 10 to 50 mol % leads to a threefold increase of the bending modulus compared to the value of the pure SOPC membrane.