Theory of Crowding Effects on Bimolecular Reaction Rates.
An analytical expression for the rate constant of a diffusion-influenced bimolecular reaction in a crowded environment is derived in the framework of a microscopic model that accounts for: (1) the slowdown of diffusion due to crowding and the dependence of the diffusivity on the distance between the reactants, (2) a crowding-induced attractive short-range potential of mean force, and (3) nonspecific reversible binding to the crowders. This expression spans the range from reaction to diffusion control. Crowding can increase the reaction-controlled rate by inducing an effective attraction between reactants but decrease the diffusion-controlled rate by reducing their relative diffusivity.
Mathematical and Statistical Computing Laboratory, Division of Computational Bioscience, Center for Information Technology, National Institutes of Health , Bethesda, Maryland 20892, United States.
Alexander M
AM
Berezhkovskii
Laboratory of Chemical Physics, National institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health , Bethesda, Maryland 20892, United States.
Attila
A
Szabo
D000818:Animals; D003198:Computer Simulation; D003593:Cytoplasm / Q000737:chemistry*; D004058:Diffusion; D005057:Eukaryotic Cells / Q000737:chemistry; D006801:Humans; D007700:Kinetics; D008956:Models, Chemical