Eur. Phys. J. E (2014) 37: 21
https://doi.org/10.1140/epje/i2014-14021-6

Regular Article

Global analysis of the ground-state wrapping conformation of a charged polymer on an oppositely charged nano-sphere

¹ Fachbereich Physik, Freie Universität Berlin, Arnimalle 14, 14195, Berlin, Germany
² School of Physics, Institute for Research in Fundamental Sciences (IPM), 19395-5531, Tehran, Iran

^* e-mail: a.naji@ipm.ir

Received: 21 November 2013
Revised: 28 February 2014
Accepted: 3 March 2014
Published online: 31 March 2014

Abstract

We investigate the wrapping conformations of a single, strongly adsorbed polymer chain on an oppositely charged nano-sphere by employing a reduced (dimensionless) representation of a primitive chain-sphere model. This enables us to determine the global behavior of the chain conformation in a wide range of values for the system parameters including the chain contour length, its linear charge density and persistence length as well as the nano-sphere charge and radius, and also the salt concentration in the bathing solution. The structural behavior of a charged chain-sphere complex can be described in terms of a few distinct conformational symmetry classes separated by continuous or discontinuous transition lines which are determined by means of appropriately defined (order) parameters. Our results can be applied to a wide class of strongly coupled polymer-sphere complexes including, for instance, complexes that comprise a mechanically flexible or semiflexible polymer chain or an extremely short or long chain and, as a special case, include the biologically relevant example of DNA-histone complexes.