二(2-苯并咪唑亚甲基)胺合钴（II）配合物与DNA作用方式的研究

本文合成并表征了二(2-苯并咪唑亚甲基)胺合钴（II）配合物。利用荧光、透析、粘度、凝胶电泳等手段，研究了其与DNA的结合机制。在20 ℃，5 mmol/L Tris-HCl (pH 7.1)和50 mmol/L NaCl缓冲溶液中，结合常数为1.96×10⁴ mol/L。应用多电解质理论对实验数据进行定量分析，结果表明该配合物与DNA主要是静电作用。粘度实验表明配合物与DNA作用时，并没有明显地改变DNA溶液的粘度，说明配合物并非以插入方式，而是以一种较微弱方式与DNA结合。同时，凝胶电泳实验证明，该配合物只能以静电作用与DNA结合，并不能产生切割作用。所有以上实验结果说明，该配合物主要是通过正负电荷间的静电作用与DNA结合。

Study on the Binding Mode of a Co(II) Complex with DNA

The mode of binding of CoLCl₂, here L=bis(2‐benzimidazolylmethyl)amine, with calf thymus DNA has been investigated by fluorescence measurements, equilibrium dialysis, viscosity experiments and gel electrophoresis. The complex was found to bind but weakly to DNA, with binding constant of 1.96×10⁴ L/mol determind at 20 °C in a solution containing 5 mmol/L Tris‐HCl (pH 7.1) and 50 mmol/L NaCl. Polyelectrolyte theory was applied to analyse these values. Viscosity experiments show that binding did not alter the relative viscosity of DNA with any complexes to an appreciable extent. Electrophoresis test displayed that the compound could not cleave the DNA. These results show that the complex is essentially electrostatically bound to DNA.