Electric dichroism of DNA. Influence of the ionic environment on the electric polarizability.
Biophys Chem
; 17(1): 35-50, 1983 Jan.
Article
em En
| MEDLINE
| ID: mdl-6824762
ABSTRACT
In order to test the diffuse ion atmosphere polarization model recently developed by us, the effects of ionic strength, titrating with Mg2+ and Co(NH3)3+6, and coion charge on the electric polarizability of short fragments of DNA are investigated. The results are consistent with the predictions of the theory and show that the diffuse ion atmosphere polarization contributes significantly to the overall orientation of DNA. At low ionic strengths, we attempt to separate the total dipole moment into two components one that agrees well with the Debye-Hückel ion atmosphere calculations, while the other, presumably due to condensed counterion polarization, appears to be substantially independent of the ionic strength. At higher salt concentrations, however, a simple separation into dipole components is not possible, perhaps due to a significant coupling of ion flows between the diffuse atmosphere and the condensed counterion layer.
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Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
DNA
Tipo de estudo:
Prognostic_studies
Limite:
Animals
Idioma:
En
Revista:
Biophys Chem
Ano de publicação:
1983
Tipo de documento:
Article