Nonequilibrium dynamics of an exactly solvable Ising-like model and protein translocation

TL;DR

This paper models protein translocation using an exactly solvable Ising-like framework with diffusive dynamics, providing precise predictions for translocation times and revealing intermediate states consistent with experimental observations.

Contribution

It introduces a novel diffusive dynamics approach on an exactly solvable model to study protein translocation, linking theoretical predictions with experimental findings.

Findings

Exact evaluation of average translocation time

Identification of intermediate states during translocation

Agreement with experimental observations

Abstract

Using an Ising-like model of protein mechanical unfolding, we introduce a diffusive dynamics on its exactly known free energy profile, reducing the nonequilibrium dynamics of the model to a biased random walk. As an illustration, the model is then applied to the protein translocation phenomenon, taking inspiration from a recent experiment on the green fluorescent protein pulled by a molecular motor. The average translocation time is evaluated exactly, and the analysis of single trajectories shows that translocation proceeds through an intermediate state, similar to that observed in the experiment.