Berezhkovskii Alexander M, Szabo Attila
Mathematical and Statistical Computing Laboratory, Division of Computational Bioscience, Center for Information Technology, National Institutes of Health , Bethesda, Maryland 20892, United States.
Laboratory of Chemical Physics, National institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health , Bethesda, Maryland 20892, United States.
J Phys Chem B. 2016 Jul 7;120(26):5998-6002. doi: 10.1021/acs.jpcb.6b01892. Epub 2016 May 2.
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.
在一个微观模型框架内，推导出了拥挤环境中扩散影响的双分子反应速率常数的解析表达式，该模型考虑了：（1）由于拥挤导致的扩散减慢以及扩散率对反应物之间距离的依赖性；（2）拥挤诱导的平均力吸引短程势；（3）与拥挤剂的非特异性可逆结合。该表达式涵盖了从反应控制到扩散控制的范围。拥挤可通过诱导反应物之间的有效吸引力来提高反应控制速率，但会通过降低它们的相对扩散率来降低扩散控制速率。
