荧光光谱法研究磷酰化5,7-二羟基黄酮与ctDNA的相互作用

Study on the Non-covalent Interaction of Diethyl Flavone-5,7-yl Phosphate with DNA by Fluorescence Method

以溴化乙锭(EB)为荧光探针,研究了磷酰化5,7-二羟基黄酮与ctDNA的相互作用。实验结果表明,磷酰化5,7-二羟基黄酮与ctDNA间存在相互作用。随着温度的升高,磷酰化5,7-二羟基黄酮对ctDNA-EB体系的荧光猝灭常数降低,磷酰化5,7-二羟基黄酮可与ctDNA形成复合物,此猝灭过程为静态猝灭。根据Stern-Volmer方程,算出25℃及37℃下磷酰化5,7-二羟基黄酮对ctDNA-EB体系的荧光猝灭常数分别为Kq1=30 860 L/mol及Kq2=27 760 L/mol,并且算出它与ctDNA结合的平衡常数为KM=2.39×107L/mol。

The non-covalent interaction of diethyl flavone-5,7-yl phosphate（DFP） with DNA was studied using ethidium bromide（EB） as a probe.The result showed that DFP could interact with DNA to form a non-covalent complex,and that the slope of the fluorescence quenching curve of ctDNA-EB would decrease with the increase of temperature under different concentrations of DFP.The quenching process was confirmed to be a static one.According to the Stern-Volmer equation,the quenching constants of DFP to DNA-EB system were 30 860 L/mol and 27 760 L/mol respectively at 25 ℃ and 37 ℃;and the binding constant of DFP and DNA-EB was 2.39×10^7 L/mol.