Analysis of Shape, Fluctuations, and Dynamics in Intermembrane Junctions

A dynamic-elastic model for weakly adhered intermembrane junctions is presented. Helfrich membrane energetics coupled to hydrodynamic modes of the surrounding solvent reproduce the average shape, fluctuations, and dynamics of these junctions as measured experimentally. Comparison between numerical results and experimental data provides the first direct measure of surface tension in these systems (0.01–0.06 dyn/cm). The measurements suggest bilayer-bilayer adhesion energetics as the dominant source of surface tension in the experimental systems.