Electronic properties of DNA-related molecules containing a bromine atom
Electronic properties of DNA-related molecules containing a bromine atom
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含有溴原子的 DNA 相关分子的电子特性
DOI：
10.1080/09553002.2020.1800121
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发表时间：
2020
影响因子：
2.6
通讯作者：
Yokoya Akinari
中科院分区：
文献类型：
--
作者：
Hirato Misaki;Onizawa Misato;Baba Yuji;Haga Yoshinori;Fujii Kentaro;Wada Shin-ichi;Yokoya Akinari
目的为了阐明含溴DNA的细胞的俄歇效应的辐射增敏机制，用X射线吸收光谱和比热测量研究了含溴DNA相关分子的电子性质，材料和方法用X射线吸收近边结构（XANES）和X射线光电子能谱（XPS）测量了含溴和不含溴的核苷酸的电子性质。我们确定了5-溴尿嘧啶晶体的比热与胸腺嘧啶作为参考分子在3-48 K的低温下计算的微观状态numbers. ResultsObserved XANES和XPS光谱表明，无论是最低未占分子轨道（LUMO）和核心能级没有受到影响的Br掺入。由25 K附近的比热计算的5-溴尿嘧啶的态数比胸腺嘧啶在20 K以下的态数大约1.5倍，尽管在5 K以下的态数几乎相同。讨论我们的结果表明，Br原子可能对分子的LUMO和芯能级电子态没有实质性贡献，而是涉及与晶格振动的激发相关的微观状态，其可能涉及价电子状态。
PurposeTo clarify the radiosensitization mechanism masking the Auger effect of the cells possessing brominated DNA, the electronic properties of DNA-related molecules containing Br were investigated by X-ray spectroscopy and specific heat measurement.Materials and MethodsX-ray absorption near-edge structure (XANES) and X-ray photoemission spectroscopy (XPS) were used to measure the electronic properties of the nucleotides with and without Br. We determined the specific heat of 5-bromouracil crystals with thymine as a reference molecule at low temperatures of 3–48 K to calculate the microscopic state numbers.ResultsObtained XANES and XPS spectra indicated that both the lowest unoccupied molecular orbital (LUMO) and the core-levels were not affected by the Br incorporation. The state numbers of 5-bromouracil calculated from the specific heats obtained around 25 K was about 1.5 times larger than that for thymine below 20 K, although the numbers were almost the same below 5 K.DiscussionOur results suggest that the Br atom may not contribute substantially to the LUMO and core-level electronic states of the molecule, but rather to the microscopic states related to the excitation of lattice vibrations, which may be involved in valence electronic states.