Nir S, Bentz J, Wilschut J
Biochemistry. 1980 Dec 23;19(26):6030-6. doi: 10.1021/bi00567a013.
The kinetics of Ca2+-induced fusion of sonicated phosphatidylserine vesicles is analyzed by means of the mass action model. The results of calculations are shown to simulate the experimental results for the mixing of aqueous vesicle volumes, release of vesicle contents and for the observed increase in light scattering [Wilschut, J., Düzgünes, N., Fraley, R., & Papahadjopoulos, D. (1980) Biochemistry (first of three papers in this issue)]. The calculations give the distribution of vesicle sizes during the initial stages of the fusion process and an estimate for the occurrence of multiple fusion events. It is estimated that during the first few seconds from the beginning of the fusion process in the above systems only a small fraction of the material trapped will leak during each fusion event. The fraction of material which leaks per fusion event is further reduced with increased Ca2+ concentrations. The values of the rates of fusion which describe the above experiments suggest that the rate limiting step of the overall fusion reaction is the aggregation and close approach of vesicles to each other rather than the fusion event per se.
通过质量作用模型分析了钙离子诱导的超声处理磷脂酰丝氨酸囊泡融合的动力学。计算结果显示能模拟囊泡水相体积混合、囊泡内容物释放以及观察到的光散射增加的实验结果[威尔舒特，J.，杜兹居内斯，N.，弗雷利，R.，& 帕帕哈吉奥普洛斯，D.（1980年）《生物化学》（本期三篇论文中的第一篇）]。计算给出了融合过程初始阶段囊泡大小的分布以及对多次融合事件发生情况的估计。据估计，在上述系统融合过程开始的最初几秒内，每次融合事件中被困物质只有一小部分会泄漏。随着钙离子浓度增加，每次融合事件中泄漏的物质比例会进一步降低。描述上述实验的融合速率值表明，整个融合反应的限速步骤是囊泡彼此聚集并紧密靠近，而非融合事件本身。
