Polymer ejection from strong spherical confinement

Abstract

We examine the ejection of an initially strongly confined flexible polymer from a spherical capsid through a nanoscale pore. We use molecular dynamics for unprecedentedly high initial monomer densities. We show that the time for an individual monomer to eject grows exponentially with the number of ejected monomers. By measurements of the force at the pore we show this dependence to be a consequence of the excess free energy of the polymer due to confinement growing exponentially with the number of monomers initially inside the capsid. This growth relates closely to the divergence of mixing energy in the Flory-Huggins theory at large concentration. We show that the pressure inside the capsid driving the ejection dominates the process that is characterized by the ejection time growing linearly with the lengths of different polymers. Waiting time profiles would indicate that the superlinear dependence obtained for polymers amenable to computer simulations results from a finite-size effect due to the final retraction of polymers' tails from capsids.

6 pages, 9 figures, accepted for publication in Phys. Rev. E, increased readability from previous version

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• Critical evaluation of the computational methods used in the forced polymer translocation
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Cited by in corpus (5)

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• Dynamics of driven translocation of semiflexible polymers
• Quantification of tension to explain bias dependence of driven polymer translocation dynamics
• Uniform description of polymer ejection dynamics from capsid with and without hydrodynamics
• Rigidity-induced scale invariance in polymer ejection from capsid