Pore formation in a lipid bilayer under a tension ramp: modeling the distribution of rupture tensions.
The rupture of fluid membrane vesicles with a steady ramp of micropipette suction has been shown to produce a distribution of breakage tensions, with a mean that rises rapidly with tension rate. Starting from a lattice model that incorporates the essential features of the lipid bilayers held together with hydrophobic forces, and developing it to handle varying tension rates, we reproduce the main features of the experimental results. In essence, we show that the rupture kinetics are driven by the nucleation and growth of pores, with two limiting kinetics-growth-limited and nucleation-limited. The model has been extended to address the role of peptides in solution that can adsorb and insert themselves into the bilayer. At concentrations below those required to spontaneously rupture the membrane, the effect of the peptides is to lower the rupture tensions systematically for all tension rates.
Boucher
Pierre-Alexandre
PA
Ottawa-Carleton Institute for Physics, University of Ottawa, Ottawa, Ontario, Canada.
Joós
Béla
B
Zuckermann
Martin J
MJ
Fournier
Luc
L
D003198:Computer Simulation; D004548:Elasticity; D057927:Hydrophobic and Hydrophilic Interactions; D008051:Lipid Bilayers / Q000737:chemistry*; D008081:Liposomes / Q000737:chemistry*; D008560:Membrane Fluidity; D008956:Models, Chemical; D008958:Models, Molecular; D016062:Porosity; D013314:Stress, Mechanical; D013500:Surface Tension
D008051:Lipid Bilayers; D008081:Liposomes