DNA纤维经醋酸处理后脱嘌呤的拉曼谱带分析  

Analysis of Raman Spectrum for DNA Fiber Treated by Acetic Acid

作　　者：余多慰[1] 柯惟中[1] 赵含英[1] 朱景宁[1] 

机构地区：[1]南京师范大学生命科学学院江苏省生物资源重点实验室,江苏南京210097

出　　处：《分析测试学报》2001年第5期1-4,共4页Journal of Instrumental Analysis

基　　金：江苏省教委自然科学基金资助项目 (1998SWX2SJ0001) ;江苏省生物资源重点实验室科研基金资助项目(1998SZS02)

摘　　要：鲱鱼精DNA纤维经醋酸处理 ,0.5h内以B型构象为主 ,这是酸溶液溶解DNA纤维的结果 ;DNA纤维在醋酸中浸润17h后 ,A、B型构象都存在 ,以A型居多 ;在拉曼光谱分析中 ,由于存在醋酸脱嘌呤的干扰 ,所以主链构象仅依磷酸脱氧核糖核酸主链—OPO—特征模得出的结论为准 ;DNA经酸处理后 ,拉曼图谱中表征N9R糖苷键的诸峰均减色明显 ,有些甚至消失 ,这表明了脱嘌呤变化 ;在该过程中 ,碱基质子化作用也极为显著 ,它与脱嘌呤变化的共同作用导致N3、N7、N9 原子两侧各键的电子云有不同程度减色 ,它们均导致了DNA双链之间氢键的断裂 ,使有关特征峰表现出相应的变化 ,但醋酸处理DNA并不导致DNA单链的断裂。Conformation of herring sperm DNA fiber in acetic acid solution was analyzed by laser Raman spectrometry. The DNA fiber exists mainly in B _ DNA conformation, treated by acetic acid within 0.5 h, but it exists in both types of A _ DNA and B _ DNA conformations, and A _ DNA conformation is in the majority, treated by acetic acid after 17 h. The characteristic peaks of glucosidic bond for N9R in Raman spectra weakens, some even disappear with the time treated by acetic acid, it indicates that purine base falls off from DNA bone chains. In this course base protonation reaction occurs obviously. Combining depurination, it led to the breakage of hydrogen bond in DNA double bound, and therefore charasteristic peaks correspondingly changes, but the acetic acid treatment does not lead to the breakage of single bond in DNA.

关 键 词：拉曼光谱 DNA纤维 醋酸 脱嘌呤 酸处理 氢键 

分 类 号：Q523[生物学—生物化学]