DNA与金属锇配合物相互作用的表面电化学研究Studyofthe.PDF

2005 年第 63 卷 化 学 学 报 Vol. 63, 2005 第 22 期, 2069～2076 ACTA CHIMICA SINICA No. 22, 2069～2076 ·研究论文· DNA 与金属锇配合物相互作用的表面电化学研究 张志凌 左 超 庞代文* (武汉大学化学与分子科学学院 武汉 430072) 摘要 采用自己建立的 DNA 表面电化学研究微量方法, 研究了单双链 DNA 与两种锇配合物(联吡啶锇和二氯菲咯啉 锇) 的相互作用. 研究发现, 两种锇配合物都是通过静电作用与 DNA 结合, 其作用方式不受溶液离子强度的影响. 并计 算得到了联吡啶锇和二氯菲咯啉锇与 dsDNA 和 ssDNA 相互作用的多个热力学和动力学参数, 如结合常数 K3＋或 K2＋, 结合常数比 K ＋/K ＋, 离子强度为零时的极限比 K 0 /K 0 , 结合自由能 ΔG , 解离速度常数 k, 结合位点数 s. 3 2 3＋ 2 ＋ b 关键词 DNA; 金属锇配合物; 相互作用; 表面电化学 Study of the Interaction between DNA and Osmium Complexes by Surface Electrochemical Method * ZHANG, Zhi-Ling ZUO, Chao PANG, Dai-Wen (College of Chemistry and Molecular Sciences, Wuhan University, Wuhan 430072) Abstract The interaction of dsDNA and ssDNA with two osmium complexes has been studied by surface electrochemical methods based on DNA modified electrode to find that both osmium complexes could bind DNA with electrostatic interaction even at high ionic strength. And some thermodynamic and kinetics con- stants, such as binding constant K3＋ or K2＋, ratio of binding constants K3＋/K2＋, limiting ratio K 0 /K 0 at 3＋ 2 ＋ zero ionic strength (I ＝0), free energy ΔG , dissociation rate constant k and binding site size s (base pair) i b have been obtained. Keywords DNA; osmium complex; interaction; surface electrochemistry