Conditions for extreme sensitivity of protein diffusion in membranes to cell environments.
We study protein diffusion in multicomponent lipid membranes close to a rigid substrate separated by a layer of viscous fluid. The large-distance, long-time asymptotics for Brownian motion are calculated by using a nonlinear stochastic Navier-Stokes equation including the effect of friction with the substrate. The advective nonlinearity, neglected in previous treatments, gives only a small correction to the renormalized viscosity and diffusion coefficient at room temperature. We find, however, that in realistic multicomponent lipid mixtures, close to a critical point for phase separation, protein diffusion acquires a strong power-law dependence on temperature and the distance to the substrate H, making it much more sensitive to cell environment, unlike the logarithmic dependence on H and very small thermal correction away from the critical point.
Tserkovnyak
Yaroslav
Y
Lyman Laboratory of Physics, Harvard University, Cambridge, MA 02138, USA.
Nelson
David R
DR
D000818:Animals; D002462:Cell Membrane / Q000737:chemistry / Q000378:metabolism*; D003198:Computer Simulation; D004058:Diffusion; D006801:Humans; D008567:Membranes, Artificial; D008954:Models, Biological; D008956:Models, Chemical; D011506:Proteins / Q000737:chemistry / Q000378:metabolism*
D008567:Membranes, Artificial; D011506:Proteins