Michaels D W, Abramovitz A S, Hammer C H, Mayer M M
Proc Natl Acad Sci U S A. 1976 Aug;73(8):2852-6. doi: 10.1073/pnas.73.8.2852.
The ion permeability of planar lipid bilayers, as measured electrically, was found to increase modestly upon treatment with purified complement complex C5b,6 and complement components C7 and C8. The subsequent addition C9 greatly amplified this change. No permeability changes occurred when components were added individually to the membrane, or when they were used in paired combinations, or when C5b, C7, C8, and C9 were admixed prior to addition. Thus, there is a significant parallel between the permeability changes induced in the model membrane and damage produced in biological membranes by the C5b-9 complement attack sequence. The efficiency of membrane action by C5b-9 was critically dependent on the order in whcih components were added to the membrane. There were also differences in the electrical properties of membranes treated with C5b-8 and C5b-9, though in both cases the enhanced bilayer permeability is best attributed to the formation of trans-membrane channels. Collectively, the data are consistent with the hypothesis that the mechanism of membrane action by complement involves the production of a stable channel across the lipid bilayer, resulting in cell death by colloid-osmotic lysis.
通过电测量发现，用纯化的补体复合物C5b,6以及补体成分C7和C8处理平面脂质双层后，其离子通透性会适度增加。随后加入C9会极大地放大这种变化。当单独将这些成分添加到膜上，或成对组合使用，或在添加之前将C5b、C7、C8和C9混合时，均未发生通透性变化。因此，在模型膜中诱导的通透性变化与C5b - 9补体攻击序列在生物膜中产生的损伤之间存在显著的平行关系。C5b - 9对膜的作用效率关键取决于向膜中添加成分的顺序。用C5b - 8和C5b - 9处理的膜在电学性质上也存在差异，不过在这两种情况下，双层膜通透性增强最主要归因于跨膜通道的形成。总体而言，这些数据与补体作用于膜的机制涉及在脂质双层中产生稳定通道从而导致细胞因胶体渗透裂解而死亡这一假说相符。
