The Effect of Cholesterol on the Voltage-Current Characteristics of Tethered Lipid Membranes.

In this study, a lipid bilayer membrane model was used, in which the bilayer is tethered to a solid substrate with molecular tethers. The V-I characteristics of the lipid bilayers were found to be non-linear which suggests the presence of pores that are voltage-dependent. At high applied voltages, the conductance reached a limiting value, presumably indicating a limit on the maximum pore size. A decrease in the spacing between tethers (increasing tether density) caused a decrease in the membrane's conductance at high applied voltage, which is consistent with the maximum pore size being determined by the spacing between the tethers. The inclusion of 10 M% cholesterol within the membrane lipid caused a decrease in the membrane conductance. However, the inclusion of higher levels of cholesterol increased the membrane conductance.