UV-A区段紫外辐射对DNA影响的拉曼光谱研究

Raman Spectrometric Study on the Influence of UV-A Radiation on DNA in Aqueous Solution

检测了小牛胸腺 DNA水溶液经 2 h和 16 h UV- A区段紫外辐射的拉曼光谱。实验结果表明 ,该区段紫外辐射对 DNA的影响要比全波段紫外辐射的影响小得多。主链构象基本上没有受到影响。经过较长时间的 UV- A区段紫外辐射后 ,DNA受到了较轻的损伤。 80 3— 816 cm-1间峰的变化表明 DNA链不同区段的构型处于不断的变化之中。脱氧核糖的特征峰 ,或强度有所下降 ,或峰发生了位移 ,或者两种变化皆有 ,表明 A区段紫外辐射对 DNA的脱氧核糖有所损伤。胸腺嘧啶的 6 81cm-1、75 2 cm-1和 1177cm-1谱线都发生了变化 ,表明胸腺嘧啶也受到了影响。但嘌呤碱基和胞嘧啶基本上没有受到影响。

The Raman spectra of calf thymus DNA in aqueous solution with 2 and 16-hour UV-A radiation were presented to study the damage of DNA molecules by UV-A radiation,which was far less than that with the whole ultraviolet radiation.The conformation of main chains hardly changed for shorter time radiation,but slightly damaged for a long time UV-A radiation.The peaks between 803cm -1 and 816cm -1 changed when DNA was UV-A radiated,and the A-type structure remained changing in aqueous solution.When DNA was UV-A radiated ,some peaks corresponding to deoxyribose changed either on peak intensity or on peak position,and some changed on both.The bands at 681,752 and 1177cm -1 ,corresponding to thymine,all changed after UV-A radiation.It proved that thymine was damaged,but UV-A radiation nearly had no influence on purine and cytosine.