Stretching an heteropolymer

TL;DR

This paper investigates how quenched disorder in monomer sequences affects the entropic elasticity of long heteropolymer chains, revealing that randomness alters elongation-force behavior and can be modeled by a renormalized elastic constant.

Contribution

It introduces a numerical and analytical study of the impact of sequence disorder on polymer elasticity within the Kratky-Porod model, providing a simple renormalization approach.

Findings

Disorder modifies elongation-force characteristics.

A renormalized elastic constant effectively describes the change.

Analytic computation of the effective coupling constant in low force regime.

Abstract

We study the influence of some quenched disorder in the sequence of monomers on the entropic elasticity of long polymeric chains. Starting from the Kratky-Porod model, we show numerically that some randomness in the favoured angles between successive segments induces a change in the elongation versus force characteristics, and this change can be well described by a simple renormalisation of the elastic constant. The effective coupling constant is computed by an analytic study of the low force regime.