TRIS(PHENANTHROLINE)RUTHENIUM(II) ENANTIOMER INTERACTIONS WITH DNA - MODE AND SPECIFICITY OF BINDING
TRIS(PHENANTHROLINE)RUTHENIUM(II) ENANTIOMER INTERACTIONS WITH DNA - MODE AND SPECIFICITY OF BINDING
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DOI：
10.1021/bi00061a015
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发表时间：
1993-03-16
期刊：
影响因子：
2.9
通讯作者：
CHAIRES, JB
中科院分区：
文献类型：
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作者：
SATYANARAYANA, S;DABROWIAK, JC;CHAIRES, JB
采用吸光度和荧光法、圆二色性、紫外熔融实验、粘度和竞争透析等方法研究DELTA和邻菲罗啉钌（II）与DNA的相互作用。这些研究的结果表明，这两种异构体结合DNA的单一模式。然而，这两种异构体的不同之处在于它们对DNA流体动力学特性的影响（用粘度来测量），因此，它们各自的结合模式可能不同。完全结合的化合物的光学性质不同于那些自由的，但它们的可见吸光度和荧光发射光谱的扰动是适度的，当与观察到的其他DNA结合化合物的变化。发现这两种异构体与DNA的结合较弱（与已证实的插入物相比），结合常数为10(4)M-1，确定它们与小牛胸腺DNA的结合。每个同分异构体与DNA的结合都有一个小的正焓，这表明结合是由熵驱动的。两种异构体都提高了DNA的熔化温度，两者之间的数量差异很小。每个异构体都有一定的碱基特异性，DELTA异构体优先结合GC碱基对，LAMBDA异构体优先结合AT碱基对。采用竞争透析法检测DELTA和LAMBDA Ru对右手性B DNA和左手性Z DNA的偏好。这两种异构体对这些完全不同的DNA二级结构都没有明显的选择性。
Absorbance and fluorescence methods, circular dichroism, UV melting experiments, viscosity, and competition dialysis were used to study the interaction of DELTA and LAMBDA tris(phenanthroline)ruthenium(II) with DNA. The results of these studies indicated that both isomers bind to DNA by a single mode. The two isomers differ, however, in their effect on the hydrodynamic properties of DNA as measured by viscosity and, therefore, probably differ in their individual binding modes. The optical properties of the fully bound compounds differ from those of the free, but the perturbations of their visible absorbance and fluorescence emission spectra are modest when compared to changes observed for other DNA binding compounds. Binding of both isomers to DNA was found to be weak (in comparison to proven intercalators), with binding constants on the order of 10(4) M-1 determined for their binding to calf thymus DNA. A small, positive enthalpy was found for the binding of each isomer to DNA, suggesting that binding is entropically driven. Both isomers increased the melting temperature of DNA, with little quantitative difference between the two. A modest base specificity was found for each isomer, with the DELTA isomer preferentially binding to GC base pairs, and the LAMBDA isomer preferentially binding to AT base pairs. Competition dialysis was used to examine the preference of DELTA and LAMBDA Ru for right-handed B DNA and left-handed Z DNA. Neither isomer exhibits significant selectivity for these radically different DNA secondary structures.