【摘要】 利用吸收光谱和荧光光谱方法，研究了吖啶橙（ＡＯ）与质粒ＤＮＡ水溶液、以及含胶束介质的吖啶橙与质粒ＤＮＡ溶液体系的相互结合作用及减色效应。结果表明：吖啶橙对质粒ＤＮＡ的吸收光谱有减色效应；含十二烷基硫酸钠（ＳＤＳ）的ＡＯ水溶液体系中，随着ＳＤＳ浓度的增加，其光谱结果表现为由凝聚态向单体的转化。而在含十二烷基硫酸钠（ＳＤＳ）的ＡＯ与质粒ＤＮＡ溶液体系中，吖啶橙凝聚态随ＳＤＳ浓度的增加，对ＡＯ与质粒ＤＮＡ相互结合产生协同的减色效应，使质粒ＤＮＡ空间结构发生缩拢。进一步采用电泳法研究了ＡＯ凝聚态可能对质粒ＤＮＡ构象的影响，结果表明：在ＡＯ与质粒ＤＮＡ溶液体系中，ＡＯ浓度的增加对质粒ＤＮＡ构象未产生影响；而在含有ＳＤＳ的ＡＯ与质粒ＤＮＡ的溶液体系中，由于ＳＤＳ对ＡＯ凝聚态的解聚作用，以及ＳＤＳ对质粒ＤＮＡ减色效应的协同作用，使得质粒ＤＮＡ的构象发生变化，诱导质粒ＤＮＡ形成超螺旋构象更多还原

【Abstract】 The binding interaction of acridine orange (AO) with plasmid DNA and the DNA hypochromic effect with and without micelle medium in the solution were investigated by absorption spectra and fluorescence spectra. The results showed that AO has hypochromic effect on DNA absorption spectra. With the increasing of sodium dodecyl sulfate (SDS) concentration in AO solution, the spectra shows the AO can change from aggregaed state to monomer. However, in the solution of plasmid DNA and AO, the increment of SDS concentration has a concerted hypochromic effect on the interaction between AO and plasmid DNA, which makes DNA contract. We further studied the possible effect of AO aggregates on plasmid DNA conformation. It appears that the increment of AO concentration has no much influence on DNA conformation in the AO and plasmid DNA solution. However, in the solution of AO and DNA with SDS,SDS has disaggregation effect on AO and concerted influence on plasmid DNA hypochromic effect, which changes the DNA co nformation and induces plasmid DNA into superhelix conformation.\=更多还原