Periodic force induced stabilization or destabilization of the denatured state of a protein

TL;DR

This study investigates how an external sinusoidal force influences protein folding, revealing that such force can both stabilize and destabilize the denatured state depending on the driving frequency, with effects modulated by temperature and viscosity.

Contribution

It demonstrates the complex effects of oscillating external forces on protein folding kinetics, highlighting stabilization and destabilization phenomena beyond traditional barrier crossing models.

Findings

Folding time varies non-monotonically with driving frequency.

External force induces stabilization or destabilization of the denatured state.

Folding dynamics depend on temperature, viscosity, and bath memory effects.

Abstract

We have studied the effects of an external sinusoidal force in protein folding kinetics. The externally applied force field acts on the each amino acid residues of polypeptide chains. Our simulation results show that mean protein folding time first increases with driving frequency and then decreases passing through a maximum. With further increase of the driving frequency the mean folding time starts increasing as the noise-induced hoping event (from the denatured state to the native state) begins to experience many oscillations over the mean barrier crossing time period. Thus unlike one-dimensional barrier crossing problems, the external oscillating force field induces both \emph{stabilization or destabilization of the denatured state} of a protein. We have also studied the parametric dependence of the folding dynamics on temperature, viscosity, non-Markovian character of bath in presence of the external field.