【摘要】 应用吸收光谱法研究了阿霉素铁（Ⅲ）［ＡＤＭ·Ｆｅ（Ⅲ）］与ＤＮＡ的结合作用，结果表明ＡＤＭ·Ｆｅ（Ⅲ）作为一个整体嵌入ＤＮＡ碱基之间形成ＡＤＭ·Ｆｅ（Ⅲ）·ＤＮＡ三元复合物。应用荧光淬灭法得到了不同Ｎａ＋浓度下ＡＤＭ及ＡＤＭ·Ｆｅ（Ⅲ）与ＤＮＡ结合作用的结合常数（Ｋ）、结合位点距离（ｎ）及标准自由能（ΔＧ），并根据多聚电解质理论将ΔＧ分解为电荷作用部分（ΔＧｐｅ）及非电荷作用部分（ΔＧｔ）。结果表明ＡＤＭ·Ｆｅ（Ⅲ）中铁离子直接参与了与ＤＮＡ的作用，ＡＤＭ·Ｆｅ（Ⅲ）较ＡＤＭ更易与ＤＮＡ结合，且结合更为紧密更多还原

【Abstract】 The interaction of ADM·Fe(Ⅲ) with DNA was investigated by absorbance spectrometry.The results indicated that ADM·Fe(Ⅲ) intercalated as a whole unit into base pairs of DNA, and formed an ADM·Fe(Ⅲ)·DNA ternary complex. The binding constant(K), exclusion parameter(n) and free energy(ΔG) of binding reactions of ADM or ADM·Fe(Ⅲ) to DNA under different concentrations of Na+ were determined by fluorescence quenching method. According to polyelectrolyte theory, the DNA binding free energy can be dissected into polyelectrolyte(ΔGpe) and nonelectrostatic(ΔGt) contributions. Comparing the above parameters, it indicated that the ferric ion in ADM·Fe(Ⅲ) interacted with DNA directly, and the binding of ADM·Fe(Ⅲ) to DNA was easier and tighter than that of ADM.更多还原