Simulation of lipid lateral diffusion in membranes.

Computer simulation of lateral diffusion of the phospholipid building blocks of membranes has been carried out using a model of random positional interchange between nearest neighbors under a wide variety of assumptions and initial conditions. Both square and hexagonal lattices have been considered, and programs have been written for the VAX 11/785 which run in as little as 30 ms processor time per completed random walk, permitting "hands on" computation. The same program runs only five times slower on the AT&T PC 6300. Diffusion on square and hexagonal lattices show remarkably similar behavior, a result which does not permit one to say that one lattice symmetry is "better."