A Unified Approach to Gated Reactions on Networks

TL;DR

This paper introduces a unified framework to analyze gated reactions on networks, linking reaction times to first-passage times, and reveals universal features and exotic kinetics caused by molecular gating.

Contribution

It develops a general approach connecting gated reaction times to ungated first-passage times, providing insights into reaction kinetics affected by molecular gating.

Findings

Reaction times can be expressed via first-passage and return times.

Universal features of gated reactions are identified.

Exotic kinetics due to gating are demonstrated through case studies.

Abstract

For two molecules to react they first have to meet. Yet, reaction times are rarely on par with the first-passage times that govern such molecular encounters. A prime reason for this discrepancy is stochastic transitions between reactive and non-reactive molecular states, which results in effective gating of product formation and altered reaction kinetics. To better understand this phenomenon we develop a unifying approach to gated reactions on networks. We first show that the mean and distribution of the gated reaction time can always be expressed in terms of ungated first-passage and return times. This relation between gated and ungated kinetics is then explored to reveal universal features of gated reactions. The latter are exemplified using a diverse set of case studies which are also used to expose the exotic kinetics that arises due to molecular gating.