KINETICS AND SEQUENCE SPECIFICITY OF DRUG DNA INTERACTIONS - AN INVITRO TRANSCRIPTION ASSAY
KINETICS AND SEQUENCE SPECIFICITY OF DRUG DNA INTERACTIONS - AN INVITRO TRANSCRIPTION ASSAY
复制标题
DOI：
10.1021/bi00371a017
复制
发表时间：
1986-11-18
期刊：
影响因子：
2.9
通讯作者：
CROTHERS, DM
中科院分区：
文献类型：
--
作者：
PHILLIPS, DR;CROTHERS, DM
已经开发了一种检测药物结合位点的DNA序列特异性的方法，以及在涉及DNA活性转录的条件下药物从这些位点解离的动力学。在放线菌素D和双插入物双（蒽环类）存在时，检测到特异性转录阻断位点；通过药物结合位点的RNA链生长速率产生药物从这些位点解离的速率。发现用洗涤剂隔离法测定的整个启动子片段的解离速率常数明显快于特定转录阻断位点的解离速率。然而，在其他药物结合位点缺乏明显的阻断意味着药物从转录复合体中这些位点的解离要快得多。我们得出结论，转录阻断是由药物-DNA复合物与RNA聚合酶的DNA序列依赖性相互作用引起的；对阻断有效的序列似乎是放线菌素的GpC和一种双曲霉素化合物的（CpA）3。转录抑制通常比简单结合表现出更大的序列特异性。
An assay has been developed to detect the DNA sequence specificity of drug binding sites, and the kinetics of dissociation of drug from those sites, under conditions involving active transcription of the DNA. Specific transcriptional blockage sites were detected in the presence of actinomycin D and a bis-intercalator, bis(anthracycline); the rate of RNA chain growth past the drug binding sites yields the rate of dissociation of drug from these sites. Rate constants for dissociation from the whole promoter fragment measured by the detergent sequestration method were found to be significantly faster than the rate determined for dissociation for the specific transcriptional blockage site. However, the absence of significant blockage at other drug binding sites implies much more rapid drug dissociation from those sites in the transcriptional complex. We conclude that transcriptional blockage results from a DNA sequence-dependent interaction of the drug-DNA complex with RNA polymerase; the sequences that are effective for blockage appear to be GpC for actinomycin and (CpA)3 for a bis(daunomycin) compound. Transcriptional inhibition may in general show greater sequence specificity than is exhibited by simple binding.