铅离子诱导超螺旋DNA断裂的研究

A Breakage of Supercoiled DNA Induced by Pb^(2+)

利用琼脂糖凝胶电泳研究了不同浓度的铅离子对准X174RFDNA超螺旋结构的影响.铅离子浓度越高,对应的DNA超螺旋百分含量-时间曲线随时间变化越明显.实验结果表明铅离子浓度为5×10-4mol/L时,超螺旋DNA结构被破坏,超螺旋形式所占的百分含量与对应的作用时间具有相关性.

Supercoiled DNA was used as a target to interact with free lead ion （Pb2＋） in the absence of redox reagents. The DNA was treated with various concentrations of Pb2＋ and incubation periods, and the amount of supercoiled DNA was determined by gel electrophoresis through intensity analysis. The results showed that a certain level of Pb2＋ （5×10-4 mol/L） would induce a structural breakage of supercoiled DNA in a time-dependent manner.