INTERACTIONS OF HETEROAROMATIC-COMPOUNDS WITH NUCLEIC-ACIDS .1. INFLUENCE OF HETEROATOMS AND POLARIZABILITY ON BASE SPECIFICITY OF INTERCALATING LIGANDS
INTERACTIONS OF HETEROAROMATIC-COMPOUNDS WITH NUCLEIC-ACIDS .1. INFLUENCE OF HETEROATOMS AND POLARIZABILITY ON BASE SPECIFICITY OF INTERCALATING LIGANDS
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DOI：
10.1111/j.1432-1033.1975.tb04137.x
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发表时间：
1975-01-01
期刊：
影响因子：
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通讯作者：
CROTHERS, DM
中科院分区：
文献类型：
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作者：
MULLER, W;CROTHERS, DM
我们已经研究了嵌入配体的碱基特异性的起源，通过研究与DNA的一系列的原黄素和吖啶橙子类似物的相互作用不同的杂原子中存在的发色团。通过对不同G · C含量的DNA样品的染料的差示透析来确定碱基特异性。我们发现，G · C特异性随着发色团的可见吸收带向较长波长移动而增加，这意味着特异性与发色团的极化率之间的关系。这可以通过认识到G · C对比A · T更极性来合理化，因此应该与容易极化的环系统更有利地相互作用。我们还发现发色团氨基的二甲基化增加了特异性，我们讨论了空间和耦合空间电子贡献，我们的结果也与放线菌素与DNA结合的G · C特异性的起源有关。研究的一些化合物具有与放线菌素一样的G · C特异性，但它们缺乏氢键功能作为特异性的合理决定因素。这一观察结果为放线菌素的特异性主要由发色团与G · C对的优先相互作用决定的假设提供了新的生命。
We have examined the origins of base specificity in intercalating ligands by studying the interaction with DNA of a series of proflavine and acridine orange analogs differing in the heteroatoms present in the chromophore. Base specificity was determined by differential dialysis of the dye against DNA samples of differing G · C content. We find that G · C specificity increases as the visible absorbance band of the chromophore moves to longer wavelength, implying a relation between specificity and polarizability of the chromophore. This can be rationalized by recognizing that the G · C pair is more polar than A · T, and should therefore interact more favorably with an easily polarized ring system. We find in addition that dimethylation of the chromophore amino groups increases specificity which we discuss in terms of steric and coupled steric‐electronic contributions.Our results also bear on the origin of G · C specificity in binding actinomycin to DNA. Some of the compounds studied are as G · C specific as actinomycin, yet they lack hydrogen‐bonding functions as plausible determinants of specificity. This observation gives new life to the hypothesis that the specificity of actinomycin is determined primarily by preferential interaction of the chromophore with a G · C pair.