脂双层膜表面结构与稳定性的原子力显微镜研究

Study of Stability and Structure of Lipid Bilayer Membrane by Atomic Force Microscope

用原子力显微镜研究了 1,2 二油酸甘油 3 磷酸 1 甘油 (DOPG)脂双层膜的表面结构与稳定性 .实验结果表明 ,原子力显微镜的探针与脂双层膜的相互作用导致脂双层膜表面产生一个永久的损伤 .静电相互作用对脂双层膜结构和稳定性的影响表明 ,在NaCl溶液中制成的脂质体 ,随着NaCl浓度的增加 ,它们的双层膜更稳定 .在低的NaCl浓度则经常被损伤 ,在 1mol/LNaCl溶液中制备的脂双层膜变得更稳定 .在KCl溶液中结果恰好相反 .在高的KCl浓度中经常被损伤 ,随着KCl浓度的降低 ,它们的双层膜更稳定 .

Stability and structure of 1, 2-dioleoyl-sn-glycero-3-[phospho-rac-1-glycerol] (DOPG) were investigated with an atomic force microscope (AFM). The results of experiments showed how the surface structure of lipid bilayer membrane could he created by the interaction between the AFM tip and lipid membrane. The tip produced a persistent deformation on the lipid bilayer membrane. Effects of electric interaction on the structure and stability of lipid bilayer membrane showed that the lipid bilayer membrane was more stable with increasing NaCl concentration. The bilayer membrane prepared in 1 mol/L NaCl was rather stable, whereas that formed at low concentration was destabilized. Using KCl instead of NaCl led to the opposite results. The lipid bilayer membrane prepared in KCl solutions at high concentration was destabilized. Stabilizing effects of the glucose and sucrose solutions on the structure of lipid bilayer membranes were also observed.