Arnold K, Ohki S, Krumbiegel M
Institute of Biophysics, Karl Marx University, Leipzig, Germany.
Chem Phys Lipids. 1990 Sep;55(3):301-7. doi: 10.1016/0009-3084(90)90168-q.
The binding of dextran sulfate to phospholipid liposomes was investigated by microelectrophoresis experiments. The polyanion binds to neutral phospholipid liposomes (DMPC and PE) only in the presence of Ca2+. If positively charged stearylamine is incorporated in the vesicles dextran sulfate is bound without Ca2+. Negatively charged phospholipids as PS do not bind dextran sulfate, even in the presence of millimolar concentrations of Ca2+. The adsorption of dextran sulfate results in an aggregation of vesicles due to a bridging mechanism. In all cases the aggregation is followed by a disaggregation toward higher dextran sulfate concentrations. The disaggregation process starts at polymer concentrations smaller than the concentration of the onset of saturation of the adsorption. By use of the probe dilution method a fusion of small DMPC and DMPC/PE vesicles in the presence of Ca2+ and dextran sulfate was found.
通过微电泳实验研究了硫酸葡聚糖与磷脂脂质体的结合。该聚阴离子仅在Ca2+存在的情况下与中性磷脂脂质体（二肉豆蔻酰磷脂酰胆碱和磷脂酰乙醇胺）结合。如果在囊泡中掺入带正电荷的硬脂胺，则硫酸葡聚糖在没有Ca2+的情况下也能结合。带负电荷的磷脂如磷脂酰丝氨酸即使在毫摩尔浓度的Ca2+存在下也不结合硫酸葡聚糖。硫酸葡聚糖的吸附由于桥联机制导致囊泡聚集。在所有情况下，聚集之后是向更高硫酸葡聚糖浓度的解聚。解聚过程在聚合物浓度小于吸附饱和起始浓度时开始。通过探针稀释法发现在Ca2+和硫酸葡聚糖存在下小的二肉豆蔻酰磷脂酰胆碱和二肉豆蔻酰磷脂酰胆碱/磷脂酰乙醇胺囊泡发生了融合。
