Tilcock C, Cullis P, Dempsey T, Youens B N, Fisher D
Department of Biochemistry, University of British Columbia, Vancouver, Canada.
Biochim Biophys Acta. 1989 Feb 27;979(2):208-14. doi: 10.1016/0005-2736(89)90436-7.
The kinetics of the partitioning of lipid vesicles containing acidic phospholipids in aqueous two-phase polymer systems are dependent upon the vesicle size; the larger the vesicles, the more readily they absorb to the interfaces between the two polymer phases and hence are cleared from the top phase as phase separation proceeds. The partitioning of neutral lipid vesicles is principally to the bulk interface and is the same in phase systems of both low and high electrostatic potential difference between the two phases (delta psi). The incorporation of negatively charged lipids has two effects upon partition. First, vesicles with negatively charged lipids exhibit increased bottom phase partitioning in phases of low delta psi due to an enhanced wetting of the charged lipids by the lower phase. Second, the presence of a negatively charged group on the vesicle surface results in increased partition to the interface and top phase in phase systems of high delta psi. Differences observed in the partition of vesicles containing various species of negatively charged lipid thus reflect a competition between these two opposing factors.
含有酸性磷脂的脂质囊泡在双水相聚合物体系中的分配动力学取决于囊泡大小；囊泡越大，它们越容易吸附到两个聚合物相之间的界面上，因此随着相分离的进行，它们会更容易从上层相中清除。中性脂质囊泡的分配主要是到本体界面，并且在两相之间静电势差（δψ）较低和较高的相体系中情况相同。带负电荷脂质的掺入对分配有两种影响。首先，由于下层相对带电荷脂质的润湿性增强，带有负电荷脂质的囊泡在低δψ的相中表现出下层相分配增加。其次，囊泡表面存在带负电荷的基团会导致在高δψ的相体系中向界面和上层相的分配增加。因此，在含有各种带负电荷脂质的囊泡分配中观察到的差异反映了这两个相反因素之间的竞争。
