Knots in Charged Polymers

Abstract

The interplay of topological constraints and Coulomb interactions in static and dynamic properties of charged polymers is investigated by numerical simulations and scaling arguments. In the absence of screening, the long-range interaction localizes irreducible topological constraints into tight molecular knots, while composite constraints are factored and separated. Even when the forces are screened, tight knots may survive as local (or even global) equilibria, as long as the overall rigidity of the polymer is dominated by the Coulomb interactions. As entanglements involving tight knots are not easy to eliminate, their presence greatly influences the relaxation times of the system. In particular, we find that tight knots in open polymers are removed by diffusion along the chain, rather than by opening up. The knot diffusion coefficient actually decreases with its charge density, and for highly charged polymers the knot's position appears frozen.

Revtex4, 9 pages, 9 eps figures

References in corpus (4)

• Equilibrium shapes of flat knots
• Tightness of slip-linked polymer chains
• Entropic Tightening of Vibrated Chains
• Quantization of energy and writhe in self-repelling knots

Cited by in corpus (8)

• Metastable tight knots in a worm-like polymer
• Sequence-specific size, structure, and stability of tight protein knots
• Stiff knots
• Chirality modifies the interaction between knots
• On the factorization of composite polymer knots into separated prime components
• Charged elastic rings: deformation and dynamics
• Entropic alignment of topologically modified ring polymers in cylindrical confinement
• Frequent Knot Discovery