How molecular knots can pass through each other

TL;DR

This paper proposes a mechanism allowing two molecular knots to pass through each other on a polymer strand, with low free energy barriers suggesting possible biological or synthetic applications.

Contribution

It introduces a novel mechanism for knot interchange on polymers, supported by simulations showing low energy barriers.

Findings

Free energy barriers are only a few $k_{B}T$.

Knots can pass through each other on DNA strands.

Potential biological implications for DNA topology.

Abstract

We propose a mechanism in which two molecular knots pass through each other and swap positions along a polymer strand. Associated free energy barriers in our simulations only amount to a few $k_{B}T$, which may enable the interchange of knots on a single DNA strand.