Relevance of the speed and direction of pulling in simple modular proteins

TL;DR

This paper presents a theoretical framework for understanding how the speed and direction of pulling affect the unfolding pathways of simple modular proteins, validated by molecular dynamics simulations.

Contribution

It introduces a theoretical analysis predicting unfolding sequences in modular proteins and validates it with steered molecular dynamics simulations.

Findings

The first module unfolds under specific pulling speeds.

Theoretical predictions match simulation results within certain velocity ranges.

Anisotropic features influence unfolding pathways.

Abstract

A theoretical analysis of the unfolding pathway of simple modular proteins in length- controlled pulling experiments is put forward. Within this framework, we predict the first module to unfold in a chain of identical units, emphasizing the ranges of pulling speeds in which we expect our theory to hold. These theoretical predictions are checked by means of steered molecular dynamics of a simple construct, specifically a chain composed of two coiled-coils motives, where anisotropic features are revealed. These simulations also allow us to give an estimate for the range of pulling velocities in which our theoretical approach is valid.