Gus'kova R A, Ivanov I I, Kol'tover V K, Akhobadze V V, Rubin A B
Biochim Biophys Acta. 1984 Dec 19;778(3):579-85. doi: 10.1016/0005-2736(84)90409-7.
Egg yolk phosphatidylcholine monolamellar liposomes (1000 A in diameter) loaded with cytochrome c were placed into an external solution, in which superoxide radicals, O2-., were generated by a xanthine-xanthine oxidase system. The penetration of the superoxide radicals across the liposomal membrane was detected by cytochrome c reduction in the inner liposome compartment. The effects of modifiers and temperature on this process were studied. The permeability of liposomal membrane for O2-. (P'O-2 = (7.6 +/- 0.3) X 10(-8) cm/s), or HO.2 (P'HO.2 = 4.9 X 10(-4) cm/s) were determined. The effect of the transmembrane electric potential (K+ concentration gradient, valinomycin) on the permeability of liposomal membranes for O2-. were investigated. It was found that O2-. can penetrate across liposomal membrane in an uncharged form. The feasibility of penetration of superoxide radicals through liposomal membrane, predominantly via anionic channels, was demonstrated by the use of an intramolecular cholesterol-amphotericin B complex.
将负载细胞色素c的蛋黄磷脂酰胆碱单层脂质体（直径1000埃）置于外部溶液中，在该溶液中，超氧自由基O₂⁻由黄嘌呤-黄嘌呤氧化酶系统产生。通过脂质体内层隔室中细胞色素c的还原检测超氧自由基穿过脂质体膜的渗透情况。研究了调节剂和温度对该过程的影响。测定了脂质体膜对O₂⁻（P'O₂ = (7.6 ± 0.3) × 10⁻⁸ cm/s）或HO₂（P'HO₂ = 4.9 × 10⁻⁴ cm/s）的渗透性。研究了跨膜电势（K⁺浓度梯度、缬氨霉素）对脂质体膜对O₂⁻渗透性的影响。发现O₂⁻可以以不带电的形式穿过脂质体膜。通过使用分子内胆固醇-两性霉素B复合物，证明了超氧自由基主要通过阴离子通道穿过脂质体膜的可行性。
