Eklund K K, Takkunen J E, Kinnunen P K
Department of Medical Chemistry, University of Helsinki, Finland.
Chem Phys Lipids. 1991 Jan-Feb;57(1):59-66. doi: 10.1016/0009-3084(91)90049-h.
Cation-induced aggregation of acidic phospholipid vesicles consisting of dimyristoylphosphatidylglycerol (DMPG), dipalmitoylphosphatidylserine (DPPS), phosphatidylserine from bovine brain (brPS), and phosphatidylglycerol from egg yolk (eggPG) was studied. Significant differences were evident in the NaCl-induced aggregation of fully saturated and unsaturated acidic phospholipid vesicles. The threshold NaCl concentration of vesicle aggregation ([NaCl]Thr) for DPPS vesicles was 320 mM compared to 610 mM observed for brPS vesicles. For DMPG vesicles the [NaCl]Thr was 430 mM and no aggregation of eggPG vesicles could be observed upon addition of NaCl. The threshold CaCl2 concentrations of aggregation of DMPG and eggPG vesicles were 2.3 and 4.9 mM, respectively. The corresponding threshold CaCl2 concentrations for DPPS and brPS vesicles were 0.85 mM and 1.3 mM, respectively. The inclusion of cholesterol into vesicles attenuated NaCl- and CaCl2-induced aggregation of DMPG and DPPS vesicles. However, enhancement of aggregation by inclusion of cholesterol was observed in the case of NaCl-induced aggregation of brPS vesicles. It is concluded that cation mediated membrane-membrane interactions depend, in addition to polar headgroup structure, on the fatty acid composition of the phospholipids also.
研究了阳离子诱导的由二肉豆蔻酰磷脂酰甘油（DMPG）、二棕榈酰磷脂酰丝氨酸（DPPS）、牛脑磷脂酰丝氨酸（brPS）和蛋黄磷脂酰甘油（eggPG）组成的酸性磷脂囊泡的聚集情况。在NaCl诱导的完全饱和和不饱和酸性磷脂囊泡聚集中，明显存在显著差异。DPPS囊泡的囊泡聚集阈值NaCl浓度（[NaCl]Thr）为320 mM，而brPS囊泡观察到的该值为610 mM。对于DMPG囊泡，[NaCl]Thr为430 mM，加入NaCl后未观察到eggPG囊泡聚集。DMPG和eggPG囊泡聚集的阈值CaCl2浓度分别为2.3 mM和4.9 mM。DPPS和brPS囊泡相应的阈值CaCl2浓度分别为0.85 mM和1.3 mM。将胆固醇加入囊泡中会减弱NaCl和CaCl2诱导的DMPG和DPPS囊泡聚集。然而，在NaCl诱导brPS囊泡聚集的情况下，观察到加入胆固醇会增强聚集。得出的结论是，阳离子介导的膜-膜相互作用除了取决于极性头基结构外，还取决于磷脂的脂肪酸组成。
