Krasilnikov O V, Sabirov R Z, Ternovsky V I, Merzliak P G, Tashmukhamedov B A
Institute of Physiology, Academy of Sciences of the UzSSR, Tashkent.
Gen Physiol Biophys. 1988 Oct;7(5):467-73.
Polyethylene glycols (PEG) with molecular weight less than or equal to 3000 were shown to effectively protect human erythrocytes from osmotic lysis induced by alpha-staphylotoxin (ST). PEG with MW less than 3000 do not change the conductivity of ion channels induced by ST in bilayer lipid membranes (BLM). Changing the bilayer from a pure phosphatidylcholine (PC) to a negatively charged phosphatidylserine (PS) film results in an asymmetry of the current-voltage characteristics. This is evidenced by the asymmetrical position of the ST-channel pore in bilayer membranes. The results obtained allow to conclude that the ST-channel is an interprotein pore filled with water (with an inner diameter of 2.5-3 nm and a length of approximately 10 nm). It is composed of six molecules of alpha-toxin from Staphylococcus aureus. The ST-channel incorporates into a membrane with only one mouth in contact with the polar lipid heads and the other one protruding 4.5-5 nm from the bilayer plane in water solution.
分子量小于或等于3000的聚乙二醇（PEG）被证明能有效保护人类红细胞免受α-葡萄球菌肠毒素（ST）诱导的渗透裂解。分子量小于3000的PEG不会改变双层脂质膜（BLM）中由ST诱导的离子通道的电导率。将双层膜从纯磷脂酰胆碱（PC）改为带负电荷的磷脂酰丝氨酸（PS）膜会导致电流-电压特性不对称。这由双层膜中ST通道孔的不对称位置证明。所得结果表明，ST通道是一个充满水的蛋白间孔（内径为2.5 - 3纳米，长度约为10纳米）。它由六个金黄色葡萄球菌α-毒素分子组成。ST通道融入膜中时，只有一个口与极性脂质头部接触，另一个口在水溶液中从双层平面突出4.5 - 5纳米。
