Counterion correlations and attraction between like-charged macromolecules.
A simple model is presented for the appearance of attraction between two like-charged polyions inside a polyelectrolyte solution. The polyions are modeled as rigid cylinders in a continuum dielectric solvent. The strong electrostatic interaction between the polyions and the counterions results in counterion condensation. If the two polyions are sufficiently close to each other their layers of condensed counterions can become correlated resulting in attraction between the macromolecules. To explore the counterion induced attraction we calculate the correlation functions for the condensed counterions. It is found that the correlations are of very short range. For the parameters specific to the double stranded DNA, the correlations and the attraction appear only when the surface-to-surface separation is less than 7 A.
Diehl
A
A
Departamento de Física, Universidade Federal do Ceará, Caixa Postal 6030, CEP 60455-760, Fortaleza, Ceará, Brazil.
Carmona
H A
HA
Levin
Y
Y
D001703:Biophysics / Q000379:methods*; D003600:Cytosol; D004247:DNA / Q000737:chemistry*; D007477:Ions; D015233:Models, Statistical; D009010:Monte Carlo Method; D055672:Static Electricity
D007477:Ions; D004247:DNA