Melting a stretched DNA

TL;DR

This paper investigates how stretching forces affect DNA melting using simulations, models, and heuristics, revealing different phase behaviors depending on force application and monomer assumptions.

Contribution

It provides a comprehensive analysis of DNA melting under stretching, highlighting the impact of force application points and monomer size assumptions on melting behavior.

Findings

Force application to one or both strands alters the phase diagram dramatically.

Monomer size assumptions lead to opposite conclusions on overstretching-induced melting.

Different models predict contrasting melting behaviors under stretching.

Abstract

We study the melting of a double stranded DNA in the presence of stretching forces, via 3D Monte-Carlo simulations, exactly solvable models and heuristic arguments. The resulting force-temperature phase diagram is dramatically different for the cases where the force is applied to only one strand or to both. Different assumptions on the monomer size of single and double stranded DNA lead to opposite conclusions as to whether DNA melts or not as it overstretches.