电化学方法研究DNA与不可逆靶向分子的相互作用

Electrochemical Methods for Studying the Interaction of DNA with Irreversible Targets

用循环伏安法、示差脉冲伏安法、计时库仑法、整体电解法和扫描电化学显微镜研究了具有抗癌活性的双苯并咪唑衍生物 (BBID)不可逆电化学行为及BBID与DNA的相互作用 ,推导了适用于研究不可逆电活性分子与DNA相互作用的电化学公式 ,该公式可以简便、快速地测定靶向分子与DNA的结合常数和结合位点数 .实验发现 ,BBID与天然鱼精DNA的结合以结构作用为主 ,同时 ,由于求得的结合常数 (K)值较大 ,因此其中可能还存在序列作用的因素 .结合方式主要为包含 4个碱基对的紧密小沟结合 .

The irreversible electrochemical behavior of bis-benzimidazole derivative (BBID) and the interaction of BBID with DNA were studied by cyclic voltammetry, differential pulse voltammetry, chronocoulometry, bulk electrolysis and scan electrochemical microscope technique. An electrochemical equation suitable for studying the interaction of irreversible redox molecule with DNA was obtained. The equation can be used to detect the binding constant (K) and binding site size (s) of BBID on DNA easily and rapidly. The experiments have proved that the main interactions between BBID and the natural fish sperm DNA were sequence mediated and structure mediated. BBID bound tightly to minor groove of the DNA which covered four base pairs.