摘要
对鲱精DNA纤维用pH 1 85酸溶液处理不同时间后 ,将样品进行拉曼光谱分析。结果表明DNA分子发生明显的质子化作用 ,有部分GC碱基对之间形成Hoogsteen型氢键的证明。酸不仅导致了DNA中部分嘌呤的脱落 ,同时还有部分嘧啶的脱落 ,其原因与嘧啶的质子化可能强于嘌呤有关。质子化、脱嘌呤、脱嘧啶的共同作用进一步引起原有正常配对的氢键断裂 ,DNA分子内双链状态不稳定 ,可见酸处理DNA时发生了酸变性这一现象 ,但其产物性质显著不同于热变性或碱变性产物。
The effects of pH 1.85 acetic acid solution treatment on the herring sperm DNA fiber have been studied by Raman spectroscopy. The studies of the Raman data indicated that the protonation of the DNA fiber is obvious. In those studies, evidence was obtained indicating that some of the protonated cytosine-guanine base pairs is a Hoogsteen type base pairs, in which the guanine conformational change enables the hydrogen bonding of N-7 of guanine and N-3 of cytosine. It was also shown that not only purine but also pyrimidine partly fall off from backbones of dsDNA after treatment with acetic acid, and the protonation of pyrimidine might be stronger than that of purine. Meanwhile, the evidence was found for the breaking of hydrogen bonds caused by protonation, depurination and depyrimidination.
出处
《光谱学与光谱分析》
SCIE
EI
CAS
CSCD
北大核心
2003年第4期734-738,共5页
Spectroscopy and Spectral Analysis
基金
江苏省教委自然科学基金 (1 998SWX2SJ0 0 0 1 )
江苏省生物资源重点实验室科研基金项目
