Effects of Noise on Coordination of Nonlinear Biochemical Systems

Abstract

Effects of noisy fluctuations in environment on coordination of nonlinear biochemical systems have been analyzed both theoretically and numerically. Once noise induces dynamical changes in a nonlinear biochemical system, response of flux to noisy fluctuations depends on both the dynamics of the system, the nature of the superimposed noise and the values of kinetical parameters, while a steady-state flux in the absence of noise may only depend on the values of kinetical parameters. For a branched biochemical system, noise may induce significant redistribution of flux among the branched reactions. Furthermore, noise may destroy coordination of a nonlinear biochemical system, when it cannot accommodate noise-induced changes. An empirical method has been suggested to determine whether coordination of a biochemical system is destroyed by environmental noise, and a general approach for studying coordination of biochemical systems under noisy fluctuations has also been presented. The theoretical results suggest that studies on coordination and homoeostasis of nonlinear biochemical systems must take their nonlinearities into account. The implications of the theoretical results for understanding flux control, homoeostasis and coordination of nonlinear biochemical systems in the presence of noise have been discussed.