Role of diffusion in the kinetics of reversible enzyme-catalyzed reactions.

The accurate expression for the steady-state velocity of an irreversible enzyme-catalyzed reaction obtained by Shin and co-workers is generalized to allow for the rebinding of the product. The amplitude of the power-law (t(-1/2)) relaxation of the free- and bound-enzyme concentrations to steady-state values is expressed in terms of the steady-state velocity and the intrinsic (chemical) rate constants. This result is conjectured to be exact, even though our expression for the steady-state velocity in terms of microscopic parameters is only approximate.