茜素红S-钆(Ⅲ)配合物与DNA的相互作用

The Interaction between Gd(Ⅲ)(ARS)_3 and DNA

在pH 7.0的中性环境下,采用紫外光谱、荧光光谱研究了茜素红S(ARS)与稀土金属Gd(Ⅲ)形成的配合物Gd(Ⅲ)(ARS)3与鲱鱼精DNA的相互作用。同时,用摩尔比法和双倒数法测得配合物的配合比nARS:nGd(Ⅲ)=3:1,Gd(Ⅲ)(ARS)3与DNA的结合常数K25℃=1.99×105L/mol,热力学函数ΔrHmθ=-9.50×104J/mol,ΔrHmθ=-3.02×104J/mol,ΔrHmθ=-217 J/mol.K。选择吖啶橙(AO)作为光谱探针,Gd(Ⅲ)(ARS)3与DNA-AO作用时,电子吸收光谱出现红移。荧光光谱研究表明Gd(Ⅲ)(ARS)3能使DNA-AO发生静态猝灭,Scatchard图显示Gd(Ⅲ)(ARS)3配合物与鲱鱼精DNA之间存在着嵌插与非嵌插混合作用方式。

Under the neutral acidity environment pH 7.0, the interaction between the Gd （ Ⅲ ） （ARS） 3 and herring-sperm DNA has been studied by UV spectra and fluorescent spectra. At the same time, the binding ratio of complex and binding constant between Gd （ Ⅲ ） （ARS） 3 and DNA were confirmed by Unity wavelength substantial amount ratio method and double reciprocal method. The binding ratio is nARS： n Gd（ Ⅲ ） =3：1 ,and the binding constant of Gd（ Ⅲ ） （ARS）3 interacting with DNA is K25℃ = 1. 99 × 105 L/mol, the thermodynamics function △rHm^θ= -9.50 ×10^4 J/mol, △rHm^θ= - 3.02 × 10^4 J/mol, △rHm^θ = -217 J/mol · K. The experiment was carried out by using Acridine orange（AO） as a probe. When the complex interacting with DNA-AO, UV spectra came out Einstein shift and isoehromatie point. The fluorescent spectra shows that Gd（ Ⅲ ）（ARS） can make DNA-AO system fluorescence static quenching. The results got by Seatehard chart indicate that both the spectroscopy intercalation action mode and dispectroscopy intercalation action mode exist between Gd（ Ⅲ ） （ARS）3 and herring-sperm DNA, including static intercalation action mode.