Theory of membrane fusion. Adhesion-condensation mechanism

The primary act of the adhesion-condensation mechanism of membrane fusion is considered. It consists in the appearance between the membranes of close dehydrated contact and in the subsequent crystallization of the molecules of the external monolayers finishing up in the zone of contact. Crystallization reduces the area occupied by one molecule and produces elastic stresses rupturing the external monolayer of the membrane in the contact zone with the other membrane. This rupture causes the formation of the tril aminar structure. It has been shown that for the formation of the trilaminar structure between vesicles with a radius of 200 Å the contact area must be not less than 22 per cent of the area of the external monolayer.