Diffusion in correlated random potentials, with applications to DNA.

摘要: Many biological processes involve one-dimensional diffusion over a correlated inhomogeneous energy landscape with correlation length xi(c). Typical examples are specific protein target location on DNA, nucleosome repositioning, or DNA translocation through nanopore, in all cases xi(c) approximately 10 nm. We investigate such transport by the mean first passage time (MFPT) formalism, and find times which exhibit strong sample to fluctuations. For displacement N, average MFPT is diffusive, while its standard deviation ensemble of profiles scales as N(3/2) large prefactor. Fluctuations thus dominant for displacements smaller than characteristic N(c) >> : typical values much less mean, governed an anomalous rule. Potential consequences random walks, composed rapid scans vicinity favorable valleys occasional jumps further valleys, discussed.