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DNA attraction in monovalent and divalent electrolytes.

ABSTRACT: The dependence of the effective force on the distance between two DNA molecules was directly computed from a set of extensive all-atom molecular dynamics simulations. The simulations revealed that in a monovalent electrolyte the effective force is repulsive at short and long distances but can be attractive in the intermediate range. This attractive force is, however, too weak (approximately 5 pN per turn of a DNA helix) to induce DNA condensation in the presence of thermal fluctuations. In divalent electrolytes, DNA molecules were observed to form a bound state, where Mg(2+) ions bridged minor groves of DNA. The effective force in divalent electrolytes was predominantly attractive, reaching a maximum of 42 pN per one turn of a DNA helix.

SUBMITTER: Luan B

PROVIDER: S-EPMC2903614 | biostudies-literature | 2008 Nov

REPOSITORIES: biostudies-literature

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DNA attraction in monovalent and divalent electrolytes.

Luan Binquan B Aksimentiev Aleksei A

Journal of the American Chemical Society 20081101 47

The dependence of the effective force on the distance between two DNA molecules was directly computed from a set of extensive all-atom molecular dynamics simulations. The simulations revealed that in a monovalent electrolyte the effective force is repulsive at short and long distances but can be attractive in the intermediate range. This attractive force is, however, too weak (approximately 5 pN per turn of a DNA helix) to induce DNA condensation in the presence of thermal fluctuations. In dival ...[more]

PMID: 18975864

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