The lateral mobility serves as a key function of the cell membrane and can be regulated by the cholesterol. Here supported lipid bilayers were used to quantitatively analyse the influence of cholesterol on the fluidity of lipid bilayer in the environments with and without an electric field. We observed that with the increase of cholesterol proportion (0−30 mol%), the diffusion coefficient of DOPC lipid bilayer gradually decreased from 1.30 ± 0.15 μm² s⁻¹ to 0.28 ± 0.13 μm² s⁻¹, where as that of DPPC lipid bilayer increased slightly from ∼0 to 0.45 ± 0.18 μm² s⁻¹. We then showed that cholesterol also regulated the movement of charged lipids in the bilayer in the electric field. The migration rate of charged lipids in the DOPC bilayers slowed down as the cholesterol increased. The clarification of the dose-effect relationship of cholesterol for the bidirectional regulating effect on the mobility of lipid bilayer will extend applications of supported lipid bilayers as the model of cell membrane.

横向迁移率是细胞膜的关键功能，可以由胆固醇调节。在此，在有电场和无电场的情况下，使用支持的脂质双层来定量分析胆固醇对脂质双层流动性的影响。我们观察到，与胆固醇比例（0-30摩尔％）的增加，DOPC脂质双层的扩散系数逐渐从1.30±0.15微米下降^2个小号^-1至0.28±0.13微米²小号^-1，其中作为DPPC的脂质双分子层从约0稍微增加至0.45±0.18微米^2个小号^-1。然后，我们证明胆固醇还可以调节电场中双层中带电脂质的运动。随着胆固醇的增加，带电荷脂质在DOPC双层中的迁移速率减慢。胆固醇对脂质双层流动性的双向调节作用的剂量效应关系的阐明将扩大支持的脂质双层作为细胞膜模型的应用。