Yokouchi Y, Tsunoda T, Imura T, Yamauchi H, Yokoyama S, Sakai H, Abe M
Faculty of Science and Technology, Science University of Tokyo, 2641, Yamazaki, Noda-shi, 278-8510, Chiba-ken, Japan
Colloids Surf B Biointerfaces. 2001 Feb 1;20(2):95-103. doi: 10.1016/s0927-7765(00)00176-4.
The effect of adsorption of bovine serum albumin (BSA) on the membrane characteristics of liposomes at pH 7.4 was examined in terms of zeta potential, micropolarity, microfluidity and permeability of liposomal bilayer membranes, where negatively charged L-alpha-dipalmitoylphosphatidylglycerol (DPPG)/L-alpha-dipalmitoylphosphatidylcholine (DPPC), negatively charged dicetylphosphate (DCP)/DPPC and positively charged stearylamine (SA)/DPPC mixed liposomes were used. BSA with negative charges adsorbed on negatively charged DPPG/DPPC mixed liposomes but did not adsorb on negatively charged DCP/DPPC and positively charged SA/DPPC mixed liposomes. Furthermore, the adsorption amount of BSA on the mixed DPPG/DPPC liposomes increased with increasing the mole fraction of DPPG in spite of a possible electrostatic repulsion between BSA and DPPG. Thus, the adsorption of BSA on liposomes was likely to be related to the hydrophobic interaction between BSA and liposomes. The microfluidity of liposomal bilayer membranes near the bilayer center decreased by the adsorption of BSA, while the permeability of liposomal bilayer membranes increased by the adsorption of BSA on liposomes. These results are considered to be due to that the adsorption of BSA brings about a phase separation in liposomes and that a temporary gap is consequently formed in the liposomal bilayer membranes, thereby the permeability of liposomal bilayer membranes increases by the adsorption of BSA.
在pH 7.4条件下，通过ζ电位、微极性、微流动性和脂质体双层膜的通透性，研究了牛血清白蛋白（BSA）吸附对脂质体膜特性的影响，其中使用了带负电荷的L-α-二棕榈酰磷脂酰甘油（DPPG）/L-α-二棕榈酰磷脂酰胆碱（DPPC）、带负电荷的十六烷基磷酸酯（DCP）/DPPC和带正电荷的硬脂胺（SA）/DPPC混合脂质体。带负电荷的BSA吸附在带负电荷的DPPG/DPPC混合脂质体上，但不吸附在带负电荷的DCP/DPPC和带正电荷的SA/DPPC混合脂质体上。此外，尽管BSA和DPPG之间可能存在静电排斥，但BSA在混合DPPG/DPPC脂质体上的吸附量随着DPPG摩尔分数的增加而增加。因此，BSA在脂质体上的吸附可能与BSA和脂质体之间的疏水相互作用有关。BSA的吸附使脂质体双层膜中心附近的微流动性降低，而BSA在脂质体上的吸附使脂质体双层膜的通透性增加。这些结果被认为是由于BSA的吸附导致脂质体中发生相分离，从而在脂质体双层膜中形成暂时的间隙，进而BSA的吸附增加了脂质体双层膜的通透性。
