Diffusion on membrane tubes : a highly discriminatory test of the Saffman-Delbruck theory

摘要: The efficient transport of membrane proteins is vital in maintaining life. In this work, we investigate the such along long thin tubes or tethers. We calculate diffusion constant to leading order low Reynolds number regime be D = (4 pi eta)-1 log(r/a), with r and a being tube protein radii, respectively, eta viscosity. Thus propose an exact limiting form for controversial logarithmic correction, as originally introduced by Saffman Delbruck, that involves radius rather than some "frame size". Our work suggests test correction could achieved measuring on tubes, exploiting fact equilibrium can controlled tension varied over several orders magnitude. analyze time taken transit between cells find vary magnitude physiological tensions. This strong effect biological terms possible regulatory coupling signaling.