MEMBRANE FUSION: KINETICS AND MECHANISMS.

The authors describe both the aggregation kinetics (where the membranes overcome the physical forces opposing their close approach, e. g. , electrostatic and hydration) and the fusion kinetics (where the destabilization of the apposed membranes can lead to either fusion or lysis). We also discuss the thermodynamic phases of lipids which sometimes govern the interaction between two liposomes. For phospholipid vesicles we have been able to identify two canonical fusion mechanisms and examples of both mechanisms where the intermembrane intermediates which cause fusion appear to be sufficiently long lived to be examined structurally.