Enhancement of Association Rates by Nonspecific Binding to DNA and Cell Membranes

A comprehensive analytic theory is developed for the kinetics of reversible association with specific sites on DNA and receptors on cell membranes in the presence of nonspecific binding to the target surfaces. Nonspecific binding is treated as a short-range attractive potential, which is more fundamental and realistic than the surface sliding model. The presence of a surface potential around the target enhances the rate of specific association and for reversible reactions leads to deviations from single exponential relaxation.