Swollen-to-Globular Transition of a Self-Avoiding Polymer Confined in a Soft Tube

Abstract

Monte Carlo simulations are presented for the structural transition of a self-avoiding polymer confined in an elastic soft tube, within the Helfrich energy model for the description of a fluctuating surface. Based on the simulation data of the maximum extension of the confined polymer in the tube and of the tube radius, a swollen-to-globular transition is identified where the confined polymer undergoes an abrupt transition from a shape elongated along the tube axis to a globule that is of much smaller dimensions than that of an unperturbed polymer. An extended regime in the parameter space has been explored where various scaling properties can be viewed.

Pressing soft membrane on a self-avoiding polymer against a flat wall

“…A polymer chain trapped inside a membrane tube can adopt a globular structure at a high surface tension [9][10][11]; a vesicle adhering onto a substrate, which confines a polymer between the membrane and substrate surfaces, induces a budding transition when the adhesion is strong enough [12][13][14]. Beyond the conformation modification, a recent in vitro experiment exploits the excluded-volume effects to scrape and staple DNA chains by vesicles to study the chain topological structure [15].…”

Equilibrium morphologies of a macromolecule under soft confinement

“…Similar theories have been applied to macromolecules in soft tubular confinement and a phase diagram characterising confined polymer shapes as a function of the surface tension and the size of the chain obtained [4]. Electrophoresis experiments on DNA confined in nanometer sized lipid tubules [9] reveal a "snake" to "globule" conformational transition [4] while Monte Carlo [22,23] and molecular dynamics [24] simulations have been used to confirm the scaling behavior. These studies however, do not fully capture the effects of semiflexibility and the nonlinear mechanics of the confining tubule on the conformational properties of the macromolecule which sets the stage of the current work.…”

Unexpected crossover dynamics of single polymer in a corrugated tube

“…In this context, one of the pioneering works to study the statics and dynamics of polymer confined in a cylinder employed Monte-Carlo simulations. 19 Studies also include the investigation of static properties, such as swollen to globule transition, in a soft tube 20 and the relaxation dynamics of polymer chains confined in a cylinder. 21 In a more recent work, it was shown that the DNA confined in a nanotube can exhibit large fluctuations at the shorter length scales and these fluctuations are ceased at longer length scales.…”