Reaction-induced molecular dancing and boosted diffusion of enzymes

TL;DR

This paper introduces a new mechanism called molecular dancing, where enzyme conformational changes induce active motion and boost diffusion without self-propulsion, explaining observed reaction-induced diffusion enhancements.

Contribution

The study develops a systematic theory and numerical simulations of reaction-induced enzyme motion, revealing a novel diffusion enhancement mechanism called molecular dancing.

Findings

Molecular dancing explains enzyme diffusion boosts observed experimentally.

Reaction rate and energy supply linearly affect diffusion enhancement.

The phenomenon may occur in other natural and synthetic systems.

Abstract

A novel mechanism of reaction-induced active molecular motion, not involving any kind of self-propulsion, is proposed and analyzed. Because of the momentum exchange with the surrounding solvent, conformational transitions in mechano-chemical enzymes are accompanied by motions of their centers of mass. As we show, in combination with rotational diffusion, such repeated reciprocal motions generate an additional random walk - or molecular dancing - and hence boost translational diffusion of an enzyme. A systematic theory of this phenomenon is developed, using as an example a simple enzyme model of a rigid two-state dumbbell. To support the analysis, numerical simulations are performed. Our conclusion is that the phenomenon of molecular dancing could underlie the observations of reaction-induced diffusion enhancement in enzymes. Major experimental findings, such as the occurrence of leaps, the anti-chemotaxis, the linear dependence on the reaction turnover rate and on the rate of energy supply, become thus explained. Moreover, the dancing behavior is possible in other systems, natural and synthetic, too. In the future, interesting biotechnology applications may be developed using such effects.