Enzymatic and physical studies on the triplex dTn.dAn.rUn.
Enzymatic and physical studies on the triplex dTn.dAn.rUn.
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三链体 dTn.dAn.rUn 的酶学和物理研究。
DOI：
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发表时间：
1973
期刊：
影响因子：
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通讯作者：
A. R. Morgan
中科院分区：
文献类型：
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作者：
N. L. Murray;A. R. Morgan
三链体dTn-dAn-rUn作为模型系统进行了研究，酶促和物理的观点，试图从体内情况下分离三链体的合理方法可能会出现。三重体的特征在于混合曲线和其平衡浮力密度。在5 mM磷酸钠（pH 7.3）中，KCl浓度低于0.4 M时，三链体解离为dTn + dAn + rUn，在约0.3 M KCl时解离完成。 如果MgCl 2取代KCl，则在1 mM MgCl 2下发生强烈的合作解离。 碱性滴定dTn → dAn → rUn时，rUn先解离，dTn → dAn后解离，酸性滴定则是三链体全部解离。dTn和dAn的转录和复制均被三链体的形成强烈抑制。当与双链体dTn/dAn或rUn相比时，三链体中的DNA和RNA部分在一定程度上受到保护，免受DNA酶I和胰腺RNA酶降解。精胺与dTn β dAn和dTn β dAn β rUn的结合同样良好，这与...
The triplex dTn∙dAn∙rUn was studied as a model system both enzymatically and physically with a view that a rational approach for attempting to isolate triplexes from in vivo situations might emerge. The triplex was characterized by mixing curves and by its equilibrium buoyant density. In 5 mM Na phosphate, pH 7.3, for KCl concentrations below 0.4 M the triplex dissociated into dTn∙dAn + rUn, dissociation being complete at about 0.3 M KCl. If MgCl2 replaced KCl a strongly cooperative dissociation occurred at 1 mM MgCl2. Whereas with alkaline titration of dTn∙dAn∙rUn, rUn was dissociated first followed by dTn∙dAn, acidic titration resulted in the whole triplex dissociating together. Both transcription and replication of dTn∙dAn were strongly inhibited by formation of a triplex. The DNA and RNA moieties in the triplex are somewhat protected against DNase I and pancreatic RNase degradation, when compared with duplex dTn∙dAn or rUn. Spermine binds equally well to dTn∙dAn and dTn∙dAn∙rUn which is consistent wit...