关键词: 超分子结构, 液晶态, 立方相, 原子力显微镜

A study by the technique of modern physics has been made on the interaction between NaCl, KCl, polyvinyl-pyrolidone (PVP), cholesterol (Chol), glucose and sucrose solutions separately and lipids. It was found that they can make conformational change of super-molecular system in the liquid crystalline state. There are stable effects of the glucose and sucrose solutions on the structure of lipid bilayer membranes. When the lipid bilayer membranes are prepared in NaCl-solutions, they are more stable with increasing NaCl concentration. For KCl it is just the opposite. By the atomic force microscope, a structure of cubic phase and bilayer phase of phosphoethanolamine (PE) was observed. The structure is closely related to the structure of amphoteric molecules, concentration, medium and pH. It was found that sodium salt solutes induce formation of an Im3m(Q²²⁹) cubic phase in DEPE dispersions. A structure transition from Im3m(Q²²⁹) to Pn3m(Q²²⁴) occurred with increasing PVP concentration in the DEPE-PVP super-molecular structures. The effect of oleic acid (OA) on DEPE(1,2-Dielaidoyl-sn-glycero-3-phosphoethanolamine)-PVP super- molecular structures was determined using a certain fixed amount. At a critical concentration of OA, a structure transition from Im3m(Q²²⁹) to Pn3m(Q²²⁴) occurred. The cholesterol promotes formation of a coexisting Pn3m(Q²²⁴) and hexagonal H_II structure. The experiments proved that the structure and function of biologic super-molecular system maybe rest with the cooperativity, directivity and selectivity of hydrogen-bonded interaction, van der Waals interaction, and electric interaction.

Key words: super-molecular ordered structure, liquid crystalline state, cubic phase, atomic force microscope