Can re-entrance be observed in force induced transitions?

TL;DR

This paper predicts and proposes an experimental method to observe re-entrance behavior in DNA force-induced transitions, demonstrating that re-entrance can occur in small oligonucleotides through combined conformational and solvent effects.

Contribution

It introduces a novel experimental protocol for observing re-entrance in DNA transitions and provides exact results supporting its feasibility.

Findings

Re-entrance can be observed in small DNA oligonucleotides.

A new experimental protocol in the constant force ensemble is proposed.

Re-entrance behavior is demonstrated through exact calculations.

Abstract

A large conformational change in the reaction co-ordinate and the role of the solvent in the formation of base-pairing are combined to settle a long standing issue {\it i.e.} prediction of re-entrance in the force induced transition of DNA. A direct way to observe the re-entrance, i.e a strand goes to the closed state from the open state and again to the open state with temperature, appears difficult to be achieved in the laboratory. An experimental protocol (in direct way) in the constant force ensemble is being proposed for the first time that will enable the observation of the re-entrance behavior in the force-temperature plane. Our exact results for small oligonucleotide that forms a hairpin structure provide the evidence that re-entrance can be observed.