Figure 6.

Alternative pathways for the dilation of hemifusion intermediates. (A) A double HD or inverted micelle intermediate (IMI) formed during fusion between a pure POPE membrane and vesicle. Note the conserved amount of isolated lipid material that is entrapped within the inner leaflet of the inverted micelle. Therefore, quite in contrast to the HD, the bulk membrane is essentially unable to absorb excess IMI material. (B) Initial crack present near the edge of the IMI, i.e., the four-bilayer junction. Propagation of the crack will cleave off a deflated vesicle. To see this figure in color, go online.