Premium
Effect of finite ionic size on the solution of the Poisson‐Boltzmann equation: Application to the binding of divalent metal ions to DNA
Author(s) -
Granot Joseph
Publication year - 1983
Publication title -
biopolymers
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.556
H-Index - 125
eISSN - 1097-0282
pISSN - 0006-3525
DOI - 10.1002/bip.360220715
Subject(s) - polyelectrolyte , divalent , counterion , chemistry , poisson–boltzmann equation , ionic bonding , ion , ionic strength , chemical physics , ionic radius , inorganic chemistry , thermodynamics , organic chemistry , aqueous solution , polymer , physics
The nonlinear Poisson‐Boltzmann equation is solved for a cylindrical polyelectrolyte solution containing mono‐ and divalent counterions and monovalent coions. The finite size of the ions is taken into account by the introduction of the distances of closest approach between the ionic charges and the surface of the polyelectrolyte. The choice of these distances is based on the physicochemical properties of the polyelectrolyte and ions in solution. The effects of the finite ionic size on the distribution of the counterions around the polyelectrolyte and on the local ion concentration and the integrated charge fraction of the divalent cations in the vicinity of the polyelectrolyte are discussed. Theoretical predictions regarding the overall extent of binding and the extent of inner‐sphere binding of divalent counterions to rodlike polyions are compared with the results of nmr studies of the binding of divalent metal ions to DNA.