Naseem I, Ahmad M, Hadi S M
Department of Biochemistry, Faculty of Life Sciences, Aligarh Muslim University, India.
Biosci Rep. 1988 Oct;8(5):485-92. doi: 10.1007/BF01121647.
Superoxide anion (O2.-) was photogenerated upon illumination of riboflavin in fluorescent light. The rate of O2.- formation was stimulated by double stranded DNA but not by denatured DNA or RNA. Depurinated DNA, which was predominantly depleted in guanine residues, did not exhibit the stimulatory effect, indicating an interaction of riboflavin, or active oxygen species derived from it, with guanine bases. Also, the stimulation of O2.- photogeneration was not observed with ethidium bromide but was seen with proflavin-intercalated DNA. Since ethidium bromide intercalates preferentially between purines and pyrimidines, and proflavin prefers dA-dT rich sites, these results were interpreted to suggest that the interaction of riboflavin with DNA is mainly with GC or CG base pairs.
在荧光灯下照射核黄素时会光生成超氧阴离子（O2.-）。双链DNA可刺激O2.-的形成速率，但变性DNA或RNA则无此作用。主要缺乏鸟嘌呤残基的脱嘌呤DNA未表现出刺激作用，这表明核黄素或其衍生的活性氧物种与鸟嘌呤碱基存在相互作用。此外，溴化乙锭未观察到对O2.-光生成的刺激作用，但原黄素插入的DNA则有此作用。由于溴化乙锭优先插入嘌呤和嘧啶之间，而原黄素更喜欢富含dA-dT的位点，因此这些结果被解释为表明核黄素与DNA的相互作用主要是与GC或CG碱基对。
