Enhanced Diffusion of Enzymes that Catalyze Exothermic Reactions

TL;DR

This paper investigates how enzyme diffusion is enhanced by catalytic exothermic reactions, analyzing proposed mechanisms and highlighting the roles of stochastic swimming and collective heating in explaining experimental observations.

Contribution

It critically evaluates four mechanisms for enzyme diffusion enhancement and identifies the most plausible ones, providing a quantitative framework for biological implications.

Findings

Only stochastic swimming and collective heating can explain the observed enhancement.

The study offers a quantitative model linking exothermicity to enzyme mobility.

Biological significance of enhanced diffusion is discussed in context.

Abstract

Enzymes have been recently found to exhibit enhanced diffusion due to their catalytic activities. A recent experiment [C. Riedel et al., Nature 517, 227 (2015)] has found evidence that suggests this phenomenon might be controlled by the degree of exothermicity of the catalytic reaction involved. Four mechanisms that can lead to this effect, namely, self-thermophoresis, boost in kinetic energy, stochastic swimming, and collective heating, are critically discussed, and it is shown that only the last two could be strong enough to account for the observations. The resulting quantitative description is used to examine the biological significance of the effect.