Alonso A, Urbaneja M A, Goñi F M, Carmona F G, Cánovas F G, Gómez-Fernández J C
Biochim Biophys Acta. 1987 Aug 20;902(2):237-46. doi: 10.1016/0005-2736(87)90301-4.
Sonicated unilamellar and large multilamellar liposome suspensions have been treated with the non-ionic detergent Triton X-100, and the subsequent changes in turbidity have been studied as a function of time. Sonicated liposome suspensions exhibit an increase in turbidity that takes place in two stages, a fast, low-amplitude one is completed in less than 100 ms, and a slow large-amplitude one occurs in 20-40 s. The first increase in turbidity is associated to detergent incorporation into the bilayer, and the second one, to vesicle fusion. The fast stage may be detected at all detergent concentrations, while the slow one is only seen above the critical micellar concentration of Triton X-100. Both processes may be interpreted in terms of first-order kinetics. Studies of the variation of kexp with lipid and detergent concentration suggest a complex multi-step mechanism. In the case of multilamellar liposomes, a fast increase in turbidity is also seen after detergent addition, which is followed by a slow (20-60 s) decrease in turbidity and a very slow (up to 12 h) large scale decrease in turbidity. These processes do not conform to single-exponential patterns. The fast stage is also thought to reflect surfactant incorporation, while the decrease in turbidity is interpreted as bilayer solubilization starting with the outer bilayer (slow stage) and proceeding through the remaining ones (very slow stage).
已用非离子型去污剂Triton X-100处理了经超声处理的单层和多层大脂质体悬浮液，并研究了随后的浊度变化随时间的函数关系。经超声处理的脂质体悬浮液的浊度增加分两个阶段进行，一个快速、低幅度的阶段在不到100毫秒内完成，一个缓慢、大幅度的阶段在20-40秒内发生。浊度的第一次增加与去污剂掺入双层有关，第二次增加与囊泡融合有关。快速阶段在所有去污剂浓度下均可检测到，而缓慢阶段仅在Triton X-100的临界胶束浓度以上出现。这两个过程都可以用一级动力学来解释。对kexp随脂质和去污剂浓度变化的研究表明存在一个复杂的多步机制。对于多层脂质体，添加去污剂后也会出现快速的浊度增加，随后是缓慢（20-60秒）的浊度降低和非常缓慢（长达12小时）的大规模浊度降低。这些过程不符合单指数模式。快速阶段也被认为反映了表面活性剂的掺入，而浊度的降低被解释为双层溶解从外层双层开始（缓慢阶段）并继续通过其余双层（非常缓慢阶段）。
