脱水在聚乙二醇诱导膜融合中的作用

DEHYDRATION OF THE PROCESS OF MEMBRANE FUSION INDUCED BY POLYETHYLENE GLYCOL (PEG)

随着各种诱导膜融合的因子相继发现,人们建立了各种膜融合的模型.我们通过对聚乙二醇PEG诱导脂质体融合的分析,认为膜融合的关键在于脱去膜表面的结合水,而其它作用诸如膜脂缺陷.膜脂分相以及脂多型性等尽管是不同膜体系中直接观察到的膜融合形式,都是膜脱去结合水带来的必然结果.膜表面结合水的排除是前因,本文着重讨论脱水及脱水后膜脂结构的一系列变化.

In this paper, we used fluorescence and freeze-fracture techniques to study the molecular mechanism of membrane fusion induced by polyethylene glycol(PEG). Our results indicated that the first step in membrane fusion process is dehydration. Only when phospholipid molecules lose the bound water, can the membranes contact closely, and the dehydration of membrane surface will soon bring about a series of changes in membrane structure, such as lipid defects, lipid lateral phase separation(domain), lipid liquid--gel phase transition and formation of nonbilayer structures, etc., which all promote the membrane fusion.