Berlin 2015 – wissenschaftliches Programm

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CPP: Fachverband Chemische Physik und Polymerphysik

CPP 21: Polymer dynamics

CPP 21.6: Vortrag

Dienstag, 17. März 2015, 10:45–11:00, C 264

Entropic segregation of ring polymers confined to a cylinder — •Elena Minina and Axel Arnold — Institute for Computational Physics, University of Stuttgart, Allmandring 3, 70569, Stuttgart, Germany

Newly replicated circular chromosomes segregate inevitably during cell division in elongated primitive bacteria such as E.coli. Although many proteins surrounding the chromosomes are possibly involved in this process, the chromosomes would also move apart without these. The reason is, that overlapping chromosomes lose conformational entropy, and the only chance to gain this entropy is to segregate. In the present study we investigate entropic segregation of ring polymers confined to a cylinder. Using MD simulations and renormalized Flory theory, we estimate how fast overlapping rings segregate and show that the obtained results can be explained by previous results on linear polymers and a simple rescaling argument. This rescaling is based on an argument that a ring can be treated as two independent chains trapped in smaller subcylinders. Our results indicate that this argument can be extended to arbitrary amounts of overlapping chains occupying different amounts of space. The polymers however start segregation only after the initial symmetry of full overlap has been broken. This induction happens by rearranging the polymer ends. We previously showed for linear chains, that this induction time grows exponentially with the polymer length, making segregation a rather slow process. The ring topology however facilitates the segregation process reducing the induction time significantly compared to linear polymers.