Dresden 2017 – scientific programme

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BP: Fachverband Biologische Physik

BP 61: Topological Problems in the Physics of Polymers, Biopolymers and Fibers II (Joint Focus Session CPP/BP)

BP 61.2: Talk

Friday, March 24, 2017, 10:30–10:45, ZEU 222

Entropic interactions between two knots on a semiflexible polymer — •Stefanie Stalter, David Richard, Jonathan Siebert, and Peter Virnau — Institut für Physik, JGU Mainz Staudingerweg 7, 55128 Mainz

Two knots on a string can either be separated or intertwined and may even pass through each other. On the microscopic scale such transitions may occur spontaneously driven by thermal fluctuations and can be associated with a topological free energy barrier. In this manuscript we study the respective location of a trefoil (3₁) and a figure-of-eight (4₁) knot on a semiflexible polymer, which is parameterized to model dsDNA in physiological conditions. Two cases are considered: First, end monomers are grafted to two confining walls of varying distance. Free energy profiles and transition barriers are then compared to a subset of free chains, which contain exactly one 3₁ and one 4₁ knot. For the latter we observe a small preference to form an intertwined state, which can be associated with an effective entropic attraction.