Symmetry relations in chemical kinetics arising from microscopic reversibility

TL;DR

This paper reveals a measurable symmetry relation in time-reversible chemical kinetics that connects reactions with the same equilibrium constant, applicable even when traditional rate constants are undefined, with implications for understanding complex biological processes.

Contribution

It introduces a new symmetry relation in chemical kinetics based on microscopic reversibility that does not depend on elementary step knowledge and applies in non-traditional regimes.

Findings

Numerical simulations confirm the symmetry relation in isomerization models.

The relation holds at short times and low activation barriers.

Potential applications in protein folding and unfolding are discussed.

Abstract

It is shown that the kinetics of time-reversible chemical reactions having the same equilibrium constant but different initial conditions are closely related to one another by a directly measurable symmetry relation analogous to chemical detailed balance. In contrast to detailed balance, however, this relation does not require knowledge of the elementary steps that underlie the reaction, and remains valid in regimes where the concept of rate constants is ill-defined, such as at very short times and in the presence of low activation barriers. Numerical simulations of a model of isomerization in solution are provided to illustrate the symmetry under such conditions, and potential applications in protein folding-unfolding are pointed out.