Electrostatic potential of B-DNA: effect of interionic correlations.
Biophys J
; 75(6): 2732-42, 1998 Dec.
Article
en En
| MEDLINE
| ID: mdl-9826596
ABSTRACT
Modified Poisson-Boltzmann (MPB) equations have been numerically solved to study ionic distributions and mean electrostatic potentials around a macromolecule of arbitrarily complex shape and charge distribution. Results for DNA are compared with those obtained by classical Poisson-Boltzmann (PB) calculations. The comparisons were made for 11 and 21 electrolytes at ionic strengths up to 1 M. It is found that ion-image charge interactions and interionic correlations, which are neglected by the PB equation, have relatively weak effects on the electrostatic potential at charged groups of the DNA. The PB equation predicts errors in the long-range electrostatic part of the free energy that are only approximately 1.5 kJ/mol per nucleotide even in the case of an asymmetrical electrolyte. In contrast, the spatial correlations between ions drastically affect the electrostatic potential at significant separations from the macromolecule leading to a clearly predicted effect of charge overneutralization.
Texto completo:
1
Colección:
01-internacional
Base de datos:
MEDLINE
Asunto principal:
ADN
Tipo de estudio:
Prognostic_studies
Idioma:
En
Revista:
Biophys J
Año:
1998
Tipo del documento:
Article
País de afiliación:
Polonia