Work distribution in manipulated single biomolecules

TL;DR

This paper investigates the relationship between microscopic and effective models in biomolecular unfolding experiments, using simulations to compare work distributions and revealing the influence of multiple time scales.

Contribution

It introduces a comparison method between detailed and effective models for biomolecule unfolding, highlighting the limitations of simplified models for slow protocols.

Findings

Good agreement for fast protocols

Discrepancies increase for slow protocols

Indicates presence of multiple time scales

Abstract

We consider the relation between the microscopic and effective descriptions of the unfolding experiment on a model polypeptide. We evaluate the probability distribution function of the performed work by Monte Carlo simulations and compare it with that obtained by evaluating the work distribution generating function on an effective Brownian motion model tailored to reproduce exactly the equilibrium properties. The agreement is satisfactory for fast protocols, but deteriorates for slower ones, hinting at the existence of processes on several time scales even in such a simple system.