双核钌配合物与c-myc G-四链体DNA的键合性能

Binding properties of a dinuclear ruthenium complex to c-myc G-quadruplex DNA

通过紫外可见吸收光谱和荧光光谱滴定、Job plot、圆二色光谱、聚合酶链式扩增反应(PCR)、显色反应以及FRET实验,研究了苯酚基双核钌配合物与c-myc G-四链体DNA(c-myc Pu27和c-myc Pu22)之间的相互作用.结果表明,配合物对c-myc Pu27和c-myc Pu22 DNA都有较强结合,键合常数分别为6.21×10^(7) L/mol和2.33×10^(6) L/mol,键和模式为沟槽结合,键合物质的量比为2∶1;配合物在浓度为4μmol/L(c-myc Pu27)、6μmol/L(c-myc Pu22)时,可完全抑制PCR扩增产物生成,表明其能够诱导c-myc DNA形成G-四链体结构.此外,配合物可使F27T和F22T的熔解温度分别升高13℃和12℃,且在双链DNA存在时F27T和F22T的熔解温度几乎没有变化,表明其对c-myc G-四链体DNA具有显著的稳定性及选择性.

The interactions of a binuclear phenol-containing ruthenium(Ⅱ)complex with c-myc G-quadruplex DNA(c-myc Pu27 and c-myc Pu22)were investigated by UV-visible absorption spectra and fluorescence spectra titrations,Job plot,CD spectra,PCR(polymerase chain reaction)stop assay,color reaction,and FRET(fluorescence resonance energy transfer)experiments.The complex bind to c-myc Pu27 and c-myc Pu22 DNA strongly with the bonding constants of 6.21×10^(7) L/mol(c-myc Pu27)and 2.33×10^(6) L/mol(c-myc Pu22)via groove mode and the binding stoichiometry is 2∶1.The replication of c-myc DNA was completely blocked by the complex at concentrations of 4μmol/L for c-myc Pu27 and 6μmol/L for c-myc Pu22,indicating that the complex can induce c-myc DNA to form a G-quadruplex structure.In addition,the complex can increase the melting temperatures of F27T and F22T by 13℃(c-myc Pu27)and 12℃(c-myc Pu22),and the melting temperatures of F27T and F22T were almost unchanged in the presence of double-stranded DNA,suggesting that the complex has significant stability and selectivity for c-myc G-quadruplex DNA.