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Study of Optical Approximation to Photoproduct Formation in Oligonucleotides by Action Spectra (50 - 300 nm).

通过作用光谱（50 - 300 nm）对寡核苷酸中光产物形成的光学近似研究。

基本信息

批准号：
01580216
负责人：
HIEDA Kotaro
金额：
$ 1.28万
依托单位：
Rikkyo University.
依托单位国家：
日本
项目类别：
Grant-in-Aid for General Scientific Research (C)
财政年份：
1989
资助国家：
日本
起止时间：
1989 至 1990
项目状态：
已结题

项目摘要

1. Thymidylyl- (3'->5') -thymidine (dTpdT) was irradiated in solid state (in vacuum) with monochromatic photons from synchrotron radiation over the wide range of wavelength : far-UV (300 - 200 nm), vacuum-UV (190 - 50 nm), soft X-rays (about 0.5 nm) and ^<60>Co gamma-rays. Photoproducts of dTpdT were analyzed by high performance liquid chromatography (HPLC), detected by absorbance at 220 nm and determined the quantities by the peak areas of HPLC chromatogram. The feasibility of optical approximation to photoproduct formation in dTpdT is studied from the viewpoint whether the results by ^<60>Co gamma-rays can be regarded as the superposition of the results by vacuum-UV.The production of cyclobutane type thymine dimers and (6-4) photoproduct were highest at 260 nm, decreased toward shorter wavelengths and became undetectable below 140 nm. These two dipyrimidine photoproducts were produced efficiently in far-UV region only.Main photoproducts induced by photons between 210 and 0.001 nm (^< … More 60>Co gamma-ray) were thymine (T), 3'-TMP and 5'-TMP, which were produced through destruction of deoxyribose moiety. The ratios among amounts of these photolysis products were almost independent on wavelength. The K-shell excitation of phosphorus induced by 2.153 keV (at resonance absorption peak of phosphorus atom) X-rays and following Auger effects had no special effect. These results indicate that deoxyribose moiety of dTpdT molecule is selectively destroyed when energies above 6 eV (wavelength below 200 nm) are absorbed through excitation, superexcitation or ionization of outer or inner shell electrons. Hence, these results do not conflict with the feasibility of the optical approximation for photoproduct induction by ^<60>Co gamma-rays.2. Main products of oligonucleotide, (pdT)_<10>, irradiated by 175 MR of 2.153 keV X-ray were T, 5'-TMP and oligonucleotides with nucleotide number from 2 to 9. The 5'-TMP and each oligonucleotide photoproduct were produced approximately same number and their total number equaled to about the number of T, indicating that all deoxyribose were equally destroyed and one destruction produced one T and two nucleotide type products (mono and oligo). Less

1.用来自同步辐射的单色光子在宽波长范围内辐照固态（真空中）胸苷酰-（3 '-> 5'）-胸苷（dTpdT）：远紫外（300 - 200 nm）、真空紫外（190 - 50 nm）、软X射线（约0.5 nm）和13 <60>Co γ射线。采用高效液相色谱法（HPLC）分析dTpdT的光产物，在220 nm处测定吸光度，并根据HPLC色谱峰面积确定其含量。从γ-Co γ射线的结果是否可视为真空紫外光的叠加的角度，研究了光产物形成的光学近似的可行性<60>。环丁烷型胸腺嘧啶二聚体和（6-4）光产物的产生在260 nm处最高，向短波长处降低，在140 nm以下变得不可检测。这两种二嘧啶光产物仅在远紫外区有效地产生。 ...更多信息 ~（60）Co γ射线照射后产生的主要产物是胸腺嘧啶（T）、3 '-TMP和5'-TMP，它们是通过破坏脱氧核糖部分而产生的。这些光解产物的数量之间的比例几乎不依赖于波长。2.153keV（磷原子共振吸收峰处）X射线引起的磷的K壳层激发及随后的俄歇效应没有特别的影响。这些结果表明，脱氧核糖部分的dTpdT分子被选择性地破坏时，能量超过6 eV（波长低于200 nm）的吸收，通过激发，超激发或电离的外壳或内壳电子。因此，这些结果与γ-Co γ射线光生产物诱导的光学近似的可行性并不矛盾<60>。寡核苷酸（pdT）_（<10>175）经2.153keVX射线辐照后，主要产物为T，5 '-TMP和核苷酸数为2 ~ 9的寡核苷酸。5 '-TMP和每种寡核苷酸光产物产生的数量大致相同，它们的总数约等于T的数量，这表明所有脱氧核糖都被同样地破坏，并且一次破坏产生一种T和两种核苷酸类型的产物（单核苷酸和寡核苷酸）。少