Detection of DNA structural changes upon drug-binging by a combination of site-selective deutaretation and difference Raman intensity changes

我的研究目标是利用“同位素编辑紫外共振拉曼光谱”-结合位点选择性同位素标记和紫外共振拉曼（UVRR）光谱来了解药物-DNA相互作用的机制。这个项目的目的是发现DNA碱基的结构和UVRR强度之间的相关性。用Kamlet和Taft提出的三个溶剂参数：氢键供体酸、氢键受体碱度和极性极化率，对腺嘌呤和鸟嘌呤衍生物在几种溶剂中的紫外拉曼光谱进行了记录，并分析了紫外拉曼光谱强度。因此，我们发现嘌呤环的拉曼强度主要取决于氢键，而不受环境极性极化率的影响。然而，我们也知道碱基堆叠相互作用会抑制DNA碱基的拉曼强度（拉曼低色度）。为了确定在拉曼光谱中是氢键还是堆积为主，我们对环AMP （cAMP）受体蛋白（CRP）结合的22聚寡核苷酸（LacDNA）进行了同位素编辑的UVRR光谱测量。CRP-(cAMP)2配合物与LacDNA的鸟嘌呤残基形成强氢键，但鸟嘌呤环的碱基堆叠并没有明显改变。对于LacDNA鸟嘌呤残基的同位素编辑UVRR光谱，一些拉曼波段在CRP-(cAMP)2结合后显示出明显的频率变化，但没有显示出有意义的强度变化。结果表明，水溶液DNA的UVRR强度主要取决于碱基堆叠的强度。我们还测量了含有ac错配碱基对的19聚寡核苷酸的同位素编辑UVRR光谱，以评估UVRR强度对碱基堆叠的敏感性。在DNA的预熔状态下检测到显著的强度变化。这一观察结果证明了同位素编辑UVRR光谱作为DNA碱基定位探针的实用性。少

The goal of my research is to understand the mechanism of drug-DNA interaction by using of"isotope-edited UV resonance Raman spectroscopy -a combination of site-selective isotope labeling and ultraviolet resonance Raman (UVRR) spectroscopy The aim of this project is to find the correlation between the structure and UVRR intensity of DNA bases.UV Raman spectra of adenine and guanine derivatives were recorded in several solvents and the intensities of UV Raman bands were analyzed by using three solvent parameters proposed by Kamlet and Taft : the hydrogen-bond donor acidy, hydrogen-bond acceptor basicity, and polarity-polarizability. As a result, we have found that the Raman intensity of the purine rings depends mostly on hydrogen bonding but little on environmental polarity-polarizability.However, it is also known that base stacking interactions suppress the Raman intensity of DNA bases (Raman hypochromism). In order to determine either hydrogen-bonding or stacking is dominant in Raman … More intensity, isotope-edited UVRR spectra were measured of a 22-mer oligonucleotide (LacDNA) bound by cyclic AMP (cAMP) receptor protein (CRP). CRP-(cAMP)2 complex forms strong hydrogen bonds with guanine residues of LacDNA, but base stacking of the guanine rings are not significantly altered by the complex. For isotope-edited UVRR spectra of the guanine residues of LacDNA, some Raman bands showed appreciable frequency changes but did not show meaningful intensity changes upon CRP-(cAMP)2 binding. It is indicated that the UVRR intensities of aqueous DNA must predominantly be determined by the strength of the base stacking. Isotope edited UVRR spectra of a 19-mer oligonucleotide containing a AC-mismatched base pair were also measured to evaluate the sensitivity of the UVRR intensity to the base stacking. A significant intensity change was detected at the pre-melting state of the DNA. This observation demonstrates the utility of isotope-edited UVRR spectroscopy as a probe of the base staking of DNA bases. Less