Onji T, Liu M S
Biochim Biophys Acta. 1979 Dec 12;558(3):320-4. doi: 10.1016/0005-2736(79)90267-0.
Changes in surface charge density of liposomes induced by E. coli endotoxin were studied by microelectrophoresis. Endotoxin altered the surface charge of phosphatidylcholine liposomes from neutral to negative. The negative charge of the endotoxin-phosphatidylcholine complex was neutralized electrostatically by binding with Ca2+ (2 mM). Phosphatidylcholine liposomes were made positive by addition of the positively charged detergent, hexadecyltrimethylammonium chloride. Endotoxin made the positively charged liposomes less charged. On the other hand, phosphatidylserine liposomes which were negatively charged became less charged in the presence of high concentration of endotoxin (8 mg/ml). The endotoxin effect on phosphatidylserine liposomes was abolished by EDTA (1 mM) but potentiated by CaCl2 (0.1--2 mM). These results indicate that endotoxin interacts with liposomes both hydrophobically and electrostatically.
通过微电泳研究了大肠杆菌内毒素诱导的脂质体表面电荷密度变化。内毒素使磷脂酰胆碱脂质体的表面电荷从中性变为负性。内毒素 - 磷脂酰胆碱复合物的负电荷通过与Ca2 +（2 mM）结合而被静电中和。通过添加带正电荷的去污剂十六烷基三甲基氯化铵使磷脂酰胆碱脂质体带正电。内毒素使带正电的脂质体电荷减少。另一方面，带负电的磷脂酰丝氨酸脂质体在高浓度内毒素（8 mg/ml）存在下电荷减少。EDTA（1 mM）消除了内毒素对磷脂酰丝氨酸脂质体的作用，但CaCl2（0.1 - 2 mM）增强了该作用。这些结果表明内毒素与脂质体既有疏水相互作用又有静电相互作用。
