Mass Action Dynamics of Coupled Reactions using Fluctuation Theory

TL;DR

This paper introduces a thermodynamic approach to modeling coupled reactions using fluctuation theory, replacing rate constants with chemical potentials, enabling more efficient simulations of metabolic networks.

Contribution

It presents a novel statistical thermodynamic formulation of mass action kinetics for coupled reactions, applicable at steady and non-stationary states, reducing computational complexity.

Findings

Rescaling of reaction dynamics achieves steady states faster.

Chemical potentials replace rate constants in models.

Potential for improved metabolic network simulations.

Abstract

Comprehensive and predictive simulation of coupled reaction networks has long been a goal of biology and other fields. Currently, metabolic network models that utilize enzyme mass action kinetics have predictive power but are limited in scope and application by the fact that the determination of enzyme rate constants is laborious and low throughput. We present a statistical thermodynamic formulation of the law of mass action for coupled reactions at both steady states and non-stationary states. The formulation is based on a fluctuation theorem for coupled reactions and uses chemical potentials instead of rate constants. When used to model deterministic systems, the theory corresponds to a rescaling of the time dependent reactions in such a way that steady states can be reached on the same time scale but with significantly fewer computational steps. The significance for applications in systems biology is discussed.