Extracting Structural Information of a Heteropolymer from Force-Extension Curves

TL;DR

This paper develops a theoretical method to infer the sequence and internal structure of heteropolymer chains from their force-extension curves, revealing insights into their binding energies and conformations during stretching.

Contribution

It introduces a reverse analysis approach to extract sequence information and structural details of hetero-polymers from experimental force-extension data.

Findings

Identifies characteristic saw-tooth patterns in force-extension curves.

Demonstrates the potential to determine binding energies of internal domains.

Provides a framework for inferring block sizes and conformations from mechanical data.

Abstract

We present a theory for the reverse analysis on the sequence information of a single H/P two-letter random hetero-polymer (RHP) from its force-extension(f-z) curves during quasi static stretching. Upon stretching of a self-assembled RHP, it undergoes several structural transitions. The typical elastic response of a hetero-polymeric globule is a set of overlapping saw-tooth patterns. With consideration of the height and the position of the overlapping saw-tooth shape, we analyze the possibility of extracting the binding energies of the internal domains and the corresponding block sizes of the contributing conformations.