INFLUENCE OF NETROPSIN AND DISTAMYCIN-A ON SECONDARY STRUCTURE AND TEMPLATE ACITVITY OF DNA
INFLUENCE OF NETROPSIN AND DISTAMYCIN-A ON SECONDARY STRUCTURE AND TEMPLATE ACITVITY OF DNA
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DOI：
10.1111/j.1432-1033.1971.tb01466.x
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发表时间：
1971-01-01
期刊：
影响因子：
--
通讯作者：
VENNER, H
中科院分区：
文献类型：
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作者：
ZIMMER, C;PUSCHENDORF, B;VENNER, H
在DNA-聚合酶和RNA-聚合酶体系中，研究了网织蛋白酶和地塞霉素A对DNA二级结构和DNA模板性质的影响。紫外吸收测量表明，由于网织蛋白酶和地塞霉素A与DNA结合，DNA-抗生素复合体具有明显的减色效应。伴随而来的是320 nm以上的吸收峰。这一紫外吸收最大值取决于DNA的(A+T)含量，在热变性后消失。这些结果以及早期的观察结果表明，Netropsin和地塞米松A寡肽的结合具有A和T的特异性。吸光度-温度测量表明，Netropsin显著提高了DNA的热稳定性。当Netropsin与100个DNA磷酸基团的比例低于5摩尔时，甚至可以获得剧烈的变化。对于DNA·netropsin比DNA·地塞米松A复合体，抗生素依赖的熔融温度升高更为明显。变性DNA的结构也受到这两种抗生素的显著影响。结果表明，Netropsin和地塞霉素A与DNA的结合是它们对双螺旋和碱基堆积区亲和力的结果，比较了这两种抗生素对DNA和RNA体外合成的影响，结果表明Netropsin和地塞米松A都能抑制DNA和RNA的聚合反应。在这两个系统中，天然和变性DNA的模板活性都受到这些抗生素的影响。以艾氏腹水癌细胞染色质为模板，核蛋白复合体对地塞米松A的作用与纯DNA一样敏感。
The action of netropsin and distamycin A on the DNA secondary structure and on the template properties of DNA in the DNA‐and RNA‐polymerase systems have been studied.Ultraviolet absorption measurements indicate characteristic hypochromic effects for the DNA‐antibiotic complexes due to binding of netropsin and distamycin A to DNA. These are accompanied by the appearance of an absorption peak beyond 320 nm. This ultraviolet absorption maximum depends on the (A+T) content of DNA and disappears upon heat denaturation. These results together with earlier observations indicate an A and T specificity of the binding of the oligopeptides netropsin and distamycin A.As demonstrated by absorbance‐temperature measurements netropsin increases considerably the thermal stability of DNA. Drastic changes can even be obtained with ratios below 5 moles netropsin per 100 DNA phosphate groups. The antibiotic dependent increase in the melting temperature is more pronounced for the DNA · netropsin than for the DNA · distamycin A complex. The structure of denatured DNA is also affected markedly by both antibiotics. From the results it is concluded that binding of netropsin and distamycin A to DNA is the result of their affinity to double‐helical and base stacked regions.Comparison of the effect of these antibiotics on DNA‐and RNA‐synthesisin vitroshows that both netropsin and distamycin A inhibit the DNA‐ and RNA‐polymerase reactions. In both systems the template activity of native as well as of denatured DNA is affected by these antibiotics. Using chromatin of Ehrlich ascites tumor cells as template it could be shown, that the nucleoprotein complex is as sensitive to the action of distamycin A as pure DNA.