Effect of counterions on the spectrum of dissolved DNA polymers.

Abstract

The effective-field model for the dynamics of DNA polymer in solution has beenextended to include the effect of monovalent counterions surrounding the polymer. The effect of site-bound counterions as compared to the area-bound counterions has been included specifically by explicitly introducing degrees of freedom for the counterions associated with a monomer and coupling these to the DNA degrees of freedom via appropriate interactions. Stability of the system for all vibrational modes was used as a criterion to find possible equilibrium positions of the site-bound counterions