Long-range energy transfer in proteins

TL;DR

This paper demonstrates that proteins can efficiently transfer energy over long distances through nonlinear localized modes, with optimal yields at biologically relevant excitation energies, revealing a potential mechanism for energy distribution within proteins.

Contribution

It introduces a coarse-grained nonlinear network model showing how proteins facilitate long-range energy transfer via localized modes, a novel insight into protein energy dynamics.

Findings

Energy can jump between sites with high yields over large distances.

Specific stiff regions are targeted during energy transfer.

Optimal energy transfer occurs at biologically relevant excitation energies.

Abstract

Proteins are large and complex molecular machines. In order to perform their function, most of them need energy, e.g. either in the form of a photon, like in the case of the visual pigment rhodopsin, or through the breaking of a chemical bond, as in the presence of adenosine triphosphate (ATP). Such energy, in turn, has to be transmitted to specific locations, often several tens of Angstroms away from where it is initially released. Here we show, within the framework of a coarse-grained nonlinear network model, that energy in a protein can jump from site to site with high yields, covering in many instances remarkably large distances. Following single-site excitations, few specific sites are targeted, systematically within the stiffest regions. Such energy transfers mark the spontaneous formation of a localized mode of nonlinear origin at the destination site, which acts as an efficient energy-accumulating centre. Interestingly, yields are found to be optimum for excitation energies in the range of biologically relevant ones.