荧光光谱法研究核黄素与鲱鱼精DNA的相互作用

在B-R缓冲溶液中, 以吖啶橙(AO)作荧光探针研究了核黄素(RF)与DNA的相互作用. 在pH值为7.25时, 荧光光谱研究表明, RF与DNA发生作用生成了复合物, 其结合比为n_RF∶n_DNA＝5∶1, 28 ℃时RF与DNA的结合常数K＝2.53×10⁶ L/mol; 并运用双倒数法求得RF与DNA相互作用的 为－6.06×10⁴ J/mol, 为－78.70 J/(mol•K), 28 ℃时的 为－3.69×10⁴ J/mol. 同时通过粘度法、盐效应和Scatchard法等研究了RF与DNA的作用方式, 确定了在该实验条件下RF与鲱鱼精DNA之间主要为沟面和静电作用方式.

Study on the Interaction between Riboflavin and Herring Sperm DNA by Fluorescence Spectrometry

The interaction of Riboflavin with DNA was studied in a Britton-Robinson buffer solution by employing acridine orange as a fluorescence probe. The fluorescence spectra indicated that a kind of compound of Riboflavin and DNA was formed when pH was 7.25. The binary compound ratio is n_RF∶n_DNA＝5∶1; the binding constant of Riboflavin with DNA compound is 2.53×10⁶ L/mol at a temperature of 28 ℃; and the thermodynamic parameters of the interaction by a double reciprocal method were calculated: ＝－6.06×10⁴ J/mol, ＝－78.70 J/(mol•K), ＝－3.69×10⁴ J/mol at 28 ℃. The interaction of Riboflavin with DNA was studied also through methods of viscosity and Scatchard as well as salt effect. The results confirm that the groove binding and electrostatic binding are the two major modes of the interaction between Riboflavin and herring sperm DNA.