School of Chemical Engineering, University of Science and Technology Liaoning, 185 Qianshan Road, Anshan, Liaoning, 114051, China.
Biosens Bioelectron. 2012 Mar 15;33(1):222-7. doi: 10.1016/j.bios.2012.01.005. Epub 2012 Jan 16.
A novel strategy of amperometric assay for drug-dsDNA interactions was developed based on an inhibitory effect of antimararial drug (quinacrine) on an electrocatalytic activity of DNA-Cu(II) complex. In this method, a DNA-Cu(II) complex immobilized DNA/polyallylamine(PAA) polyion complex membrane was used as a sensing element. The electrocatalytic activity of a DNA-Cu(II) complex for hydrogen peroxide reduction was reversibly inhibited by electron blocking effect of quinacrine-dsDNA interaction and this inhibitory effect was amplified by the hydrogen peroxide reduction. This phenomenon was utilized for development of a novel amperometric biosensor for DNA-binding drug. From the amperometric current-time curves, the response time of the sensor to 20 μM quinacrine was obtained about 20s, and the detection limit of the quinacrine was found to be 10 μM estimated to a signal-to-noise ratio of 3.0. Based on the change of steady-state catalytic current, the kinetic analysis of drug-dsDNA interaction can be done in a similar manner of enzyme inhibition, and the binding constant of the quinacrine with DNA can be calculated. This measurement method would be useful for screening of wide variety of DNA-binding drugs and highly toxic pollutants.
基于抗疟药物（奎宁）对 DNA-Cu(II) 配合物电催化活性的抑制作用，开发了一种用于药物-DNA 相互作用的电流测定分析新策略。在该方法中，将 DNA-Cu(II) 配合物固定在 DNA/聚烯丙胺（PAA）聚离子复合物膜上作为传感元件。DNA-Cu(II) 配合物对过氧化氢还原的电催化活性可被奎宁-DNA 相互作用的电子阻断效应可逆抑制，并且这种抑制作用可通过过氧化氢还原得到放大。这种现象可用于开发用于 DNA 结合药物的新型电流测定生物传感器。从电流-时间曲线可以得到传感器对 20 μM 奎宁的响应时间约为 20s，并且发现奎宁的检测限约为 10 μM，估计信噪比为 3.0。基于稳态催化电流的变化，可以以类似于酶抑制的方式进行药物-DNA 相互作用的动力学分析，并可以计算奎宁与 DNA 的结合常数。这种测量方法将有助于筛选各种 DNA 结合药物和高毒性污染物。
