DNA Compaction and Charge Neutralization Regulated by Divalent Ions in very Low pH Solution.

ABSTRACT: DNA conformation is strongly dependent on the valence of counterions in solution, and a valence of at least three is needed for DNA compaction. Recently, we directly demonstrated DNA compaction and its regulation, mediated by divalent cations, by lowering the pH of a solution. In the present study, we found that the critical electrophoretic mobility of DNA is promoted to around -1.0 × 10-4 cm² V-1 s-1 to incur DNA compaction or condensation in a tri- and tetravalent counterions solution, corresponding to an about 89% neutralized charge fraction of DNA. This is also valid for DNA compaction by divalent counterions in a low pH solution. It is notable that the critical charge neutralization of DNA for compaction is only about 1% higher than the saturated charge fraction of DNA in a mild dival

SUBMITTER: Gao T 

PROVIDER: S-EPMC6419228 | biostudies-literature | 2019 Feb

REPOSITORIES: biostudies-literature