Mechanics of membrane fusion

Abstract

Diverse membrane fusion reactions in biology involve close contact between two lipid bilayers, followed by the local distortion of the individual bilayers and reformation into a single, merged membrane. We consider the structures and energies of the fusion intermediates identified in experimental and theoretical work on protein-free lipid bilayers. On the basis of this analysis, we then discuss the conserved fusion-through-hemifusion pathway of merger between biological membranes and propose that the entire progression, from the close juxtaposition of membrane bilayers to the expansion of a fusion pore, is controlled by protein-generated membrane stresses.

Membrane blebbing as a recovery manoeuvre in site-specific sonoporation mediated by targeted microbubbles

“…Perhaps two recovery manoeuvres that may take place during sonoporation are endocytosis-mediated membrane reunion and exocytosismediated vesicular patching [25]. The former is suggested to be applicable to nanometre-sized pores [26], while the latter is often invoked in cases with acute calcium ion (Ca 2þ ) influx [27], which would indeed arise during sonoporation [28,29]. However, the caveat in solely relying on these two manoeuvres to underscore the recovery phase of sonoporation is that they cannot serve to explain why significant membrane protrusions were observed in some sonoporated cells [23].…”

Imprintable membranes from incomplete chiral coalescence

“…For complex fluids with partial positional and/or orientational order, the complexity of the coalescence reactions increases considerably 6 . A well-studied example belonging to this category is lipid vesicles, whose fusion is characterized by complex barriers that include structural distortions, which expose the hydrophobic core of the lipid bilayer and allow the merger to proceed [7][8][9] . In addition to fluid droplets and vesicles, coalescence is also important in the formation of solid structures such as carbon nanotubes or sintered powders 10,11 .…”

Membrane-Transferring Regions of gp41 as Targets for HIV-1 Fusion Inhibition and Viral Neutralization

“…These effects would result in the creation of bulges (or dimples) that protrude from the membrane plane [46]. The tops of these structures are highly curved, an arrangement that can facilitate the formation of lipidic contacts between fusing bilayers [46]. Alternatively, based on the evidence that MTRs may lower the membrane rupture tension [47], it has been proposed that a plausible mechanism of MTR-mediated fusion-promotion could be the destabilization of bilayer diaphragms at hemifusion intermediates [40].…”

“…These effects would result in the creation of bulges (or dimples) that protrude from the membrane plane [46]. The tops of these structures are highly curved, an arrangement that can facilitate the formation of lipidic contacts between fusing bilayers [46].…”