Ward B, Rehfuss R, Goodisman J, Dabrowiak J C
Department of Chemistry, Syracuse University, NY 13244-1200.
Nucleic Acids Res. 1988 Feb 25;16(4):1359-69. doi: 10.1093/nar/16.4.1359.
Footprinting experiments for DNase I digests of a 139-base-pair segment of pBR-322 DNA in the presence of either netropsin or actinomycin D were carried out. Plots of oligonucleotide concentration as a function of drug concentration were analyzed to study the enhancement in cleavage rates at approximately 30 sites, accompanying drug binding at other sites. The pattern of enhancements is not consistent with drug-induced DNA structural changes, but agrees with a redistribution mechanism involving DNase I. Since the total number of enzyme molecules per fragment remains unchanged, drug binding at some sites increases the enzyme concentration at other sites, giving rise to increased cleavage. The consequences of the redistribution mechanism for analysis of footprinting experiments are indicated.
在存在纺锤菌素或放线菌素D的情况下，对pBR - 322 DNA的139个碱基对片段进行了DNase I消化的足迹实验。分析了寡核苷酸浓度与药物浓度的关系图，以研究在大约30个位点处切割速率的增强情况，这伴随着药物在其他位点的结合。增强模式与药物诱导的DNA结构变化不一致，但与涉及DNase I的重新分布机制相符。由于每个片段中酶分子的总数保持不变，药物在某些位点的结合会增加其他位点的酶浓度，从而导致切割增加。文中指出了重新分布机制对足迹实验分析的影响。
