核黄素与脱氧核糖核酸相互作用的电化学和光谱法研究

在实验条件接近人体生理环境的pH7.4的Tris-HCl缓冲溶液中,分别采用电化学方法、紫外光谱法及荧光法并利用中性红作电化学探针,研究了核黄素和小牛胸腺DNA的相互作用。随着DNA浓度逐渐增加,核黄素的峰电流减小,峰位正移;紫外光谱产生减色效应;核黄素的荧光发生猝灭以及核黄素和中性红竞争与DNA相互作用等,采用几种方法的实验结果都表明两者能发生嵌插结合;多种计算方法得到两者作用的结合位点数为1,结合常数达到105(mol/L)-1。

Electrochemical and Spectral Investigation on Interaction Between Riboflavin with Deoxyribonucleic Acid

The interaction between riboflavin(VB_2) and deoxyribonucleic acid (DNA) was studied by electrochemistry , ultraviolet spectrophotometry and fluorescence spectrometry. Neutral red was also used as electrochemical probe. The results of these methods (peak current of riboflavin decreased and the peak potential shifted positively; the ultralviolet spectrum produced hypochromic effect; the fluorescence had quenching effect with increasing the concentration of DNA and the competition between riboflavin and neutral red interacted with DNA) can come to a conclusion: riboflavin binds to DNA mainly by intercalation. Information such as intrinsic binding constant and binding numbers of riboflavin per DNA was also obtained through numerous calculations respectively, the result is approximate and believable.