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

本研究的目的是利用同位素编辑的紫外共振拉曼光谱--定点选择性同位素标记和紫外共振拉曼光谱相结合的方法来了解药物与DNA的相互作用机理。本研究的目的是寻找DNA碱基的结构与紫外共振拉曼光谱强度之间的相关性。结果发现，嘌呤环的拉曼强度主要取决于氢键，而与环境的极性-极化率关系不大。然而，我们也知道碱基堆积作用抑制了DNA碱基的拉曼强度(拉曼变色)。为了确定在拉曼…中氢键或堆积占主导地位更强的，同位素编辑的UVRR光谱被测量到与环AMP(CAMP)受体蛋白(CRP)结合的22聚体寡核苷酸(LacDNA)。CRP-(CAMP)2与LacDNA的鸟嘌呤残基形成强氢键，但鸟嘌呤环的碱基堆积没有明显变化。对于LacDNA鸟嘌呤残基的同位素编辑的UVRR谱，一些拉曼光谱在CRP-(CAMP)2结合时显示出明显的频率变化，但没有显示有意义的强度变化。结果表明，DNA水分子的UVRR强度主要取决于碱基堆积的强度。还测量了含有AC不匹配碱基对的19聚体寡核苷酸的同位素编辑UVRR谱，以评估UVRR强度对碱基堆积的敏感性。在DNA的预熔融态检测到了显著的强度变化。这一观察证明了同位素编辑的UVRR光谱作为DNA碱基标记的探针的实用性。较少

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