Inter-DNA attraction mediated by divalent counterions
Inter-DNA attraction mediated by divalent counterions
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DOI：
10.1103/physrevlett.99.038104
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发表时间：
2007-07-20
影响因子：
8.6
通讯作者：
Pollack, Lois
中科院分区：
文献类型：
--
作者：
Qiu, Xiangyun;Andresen, Kurt;Pollack, Lois
Can nonspecifically bound divalent counterions induce attraction between DNA strands? Here, we present experimental evidence demonstrating attraction between short DNA strands mediated by Mg2+ ions. Solution small angle x-ray scattering data collected as a function of DNA concentration enable model independent extraction of the second virial coefficient. As the [Mg2+] increases, this coefficient turns from positive to negative reflecting the transition from repulsive to attractive inter-DNA interaction. This surprising observation is corroborated by independent light scattering experiments. The dependence of the observed attraction on experimental parameters including DNA length provides valuable clues to its origin.
