Effects of β-Sitosteryl Sulfate on the Hydration Behavior of Dipalmitoylphosphatidylcholine

抄録

We investigated the hydration behavior of dipalmitoylphosphatidylcholine (DPPC) bilayers containing sodium β-sitosteryl sulfate (PSO₄). PSO₄ was found to enhance hydration in the headgroup region of DPPC bilayers. Therefore, with the incorporation of PSO₄ into DPPC membranes, the amount of water required to reach the fully hydrated state was enhanced as indicated by the constant values of the main phase transition temperature (T_m) and the bilayer repeat distance (d). For example, with the addition of 20 mol% of PSO₄, the saturation point was shifted to ~70 wt% water compared to ~40 wt% for pure DPPC and 47 wt% for DPPC-cholesterol. The effectiveness of PSO₄ in fluidizing the membrane and enhancing its hydration state can be useful in the pharmaceutical and cosmetic industries.