Lateral diffusion of molecules in two-component lipid bilayer: A monte carlo simulation study

The simulation of equilibrium lateral diffusion of intrinsic molecules in an equimolar DMPC/DSPC mixture was carried out using a thoroughly tested two-state model of two-component phospholipid bilayers. A diffusing intrinsic molecule change gel/fluid mixed phase region, from fluid to gel at any time. The calculated relative diffusion coefficient decreases in the gel/fluid mixed phase region with decreasing temperature. The diffusion measured by fluorescence recovery after photobleaching (FRAP) demonstrated the existence of a threshold temperature, below which long-range diffusion of FRAP probe molecules was essentially blocked.