DNA变性剂对乳糖阻遏蛋白-操纵基因相互作用的影响。

Effect of DNA denaturants on the lac repressor-operator interaction.

作者信息

Pfahl M

出版信息

Biochim Biophys Acta. 1978 Sep 27;520(2):285-90. doi: 10.1016/0005-2787(78)90227-7.

Abstract

The nitrocellulose filter assay was used to study the effect of the DNA denaturants glycerol and dimethylsulfoxide (Me2SO) on the lac repressor-operator interaction. Both glycerol and Me2SO decrease the rate of dissociation (kb) of the repressor-operator complex but do not significantly alter the rate of association of repressor and operator. In the presence of 10% Me2SO an almost 10-fold increase of affinity of repressor for operator is observed. A small increase in affinity of repressor for Escherichia coli DNA, chicken blood DNA, and poly(dA-dT) is also found. The results lead to the conclusion that lac repressor when interacting with the operator causes local destabilization of the DNA.

摘要

采用硝酸纤维素滤膜分析法研究了DNA变性剂甘油和二甲基亚砜（Me2SO）对乳糖阻遏蛋白与操纵基因相互作用的影响。甘油和Me2SO均降低了阻遏蛋白-操纵基因复合物的解离速率（kb），但对阻遏蛋白与操纵基因的结合速率没有显著影响。在10% Me2SO存在的情况下，观察到阻遏蛋白对操纵基因的亲和力几乎增加了10倍。还发现阻遏蛋白对大肠杆菌DNA、鸡血DNA和聚（dA-dT）的亲和力有小幅增加。结果得出结论，乳糖阻遏蛋白与操纵基因相互作用时会导致DNA局部不稳定。