One-electron oxidation of condensed DNA toroids: injection-site dependent charge (radical cation) mobility
1School of Chemistry and Biochemistry, Georgia Institute of Technology, Atlanta, Georgia 30332, USA.
Abstract:
DNA condensates were formed by treating linear pUC19 plasmids ligated to an AQ-containing oligomer with spermidine. The condensates are toroid-shaped objects having a radius of 70 to 100 nm. Irradiation of the condensates with UV light (absorbed by the anthraquinone) causes the one-electron oxidation of the DNA and concomitant reaction at GG steps of the oligomer. Analysis of the distance dependence of the reaction at guanine in these condensates reveals a dependency on the position of the AQ. This observation is attributed to a reduction in the rate for trapping of the radical cation in the relatively dehydrated interior of the condensate.
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