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

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.