Abstract: The dynamic and stability characteristics of lipid raft in the biomembrane have great effect on many biological processes. Extracted lipid rafts from animal cells, not only flask-shaped caveolae but also spherical and ellipsoidal morphology have been observed. Simulated the lipid raft in vitro and focused on the binary and ternary system to study the polymorphisms of membrane structure. The results showed that SM/Chol bilayer appeared tightly clustered irregular microdomains with the increase in surface pressure. For the SM/Chol/DOPC bilayer system, the microdomains formed by SM/Chol floated on the fluid small DOPC area. When DOPE added to the SM/Chol, the bilayers structure became unstable. Ceramide induced SM/Chol bilayer rearrangement, from original irregular structure to closely aggregated round structure. In the mixed monolayers, the molecular area and surface Gibbs free energy determines the molecular interactions. When the excess molecular and excess Gibbs energy is negative deviations from ideality, the interaction between molecules is attractive and the monolayer is more aggregated. Positive deviation from linearity indicates repelling interaction and the monolayer forms phase separation structure. The less the Gibbs energy value, more stable the monolayer is. Combined extraction from animal cells and simulated in vitro methods, study the biological significance of lipid raft between structure and function from super-molecular level. This project conduction can provide theoretical evidence and experimental support for studying biomembrane.

Key words: Lipid raft;  , Microdomain;  , Supramolecular aggregate;  , Dynamic characteristic;  , Stability