Seasonal Differences in the UVA/UVB Ratio of Natural Sunlight Influence the Efficiency of the Photoisomerization of (6-4) Photoproducts into their Dewar Valence Isomers.

• Material Type: 博士論文
• Title: Seasonal Differences in the UVA/UVB Ratio of Natural Sunlight Influence the Efficiency of the Photoisomerization of (6-4) Photoproducts into their Dewar Valence Isomers.
• Author/Editor: Nishimura, Kazuki; Ikehata, Hironobu; Douki, Thierry; Cadet, Jean; Sugiura, Shigeki; Mori, Toshio
• Author Heading: Nishimura, Kazuki; Ikehata, Hironobu; Douki, Thierry; Cadet, Jean; Sugiura, Shigeki; Mori, Toshio
• Publication, Distribution, etc.: Wiley
• Publication Date: 2021-05
• Publication Date (W3CDTF): 2021-05
• Alternative Title: 太陽光中のUVA/UVBの比率の季節差がDNA損傷（6-４）型光産物のDewar型光産物への光異性化の効率に影響を及ぼす
• Periodical title: Photochemistry and photobiology
• No. or year of volume/issue: 97 3
• Volume: 97
• Issue: 3
• Pages: 582-588
• ISSN (Periodical Title): ISSN : 0031-8655
• Degree grantor/type: 奈良県立医科大学
• Date Granted: 2021-03-15
• Dissertation Number: 甲第775号
• Degree Type: 博士（医学）
• Text Language Code: eng
• Target Audience: 一般
• Note (General): type:Thesis; The UVA and UVB components of sunlight can produce three classes of bipyrimidine DNA photolesions [cyclobutane pyrimidine dimers (CPDs), pyrimidine (6-4) pyrimidone photoproducts (6-4PPs) and related Dewar valence isomers (DewarPPs)]. The UVA/UVB ratio of sunlight is high in winter and low in summer in the Northern Hemisphere. Since UVB radiation produces 6-4PPs and UVA radiation converts them into DewarPPs through photoisomerization, it is expected that there may be differences in the photoisomerization of 6-4PPs between summer and winter, although that has never been documented. To determine that, isolated DNA was exposed to natural sunlight for 8 h in late summer and in winter, and absolute levels of the three classes of photolesions were quantified using calibrated ELISAs. It was found that sunlight produces CPDs and 6-4PPs in DNA at a ratio of about 9:1 and converts approximately 80% of 6-4PPs into DewarPPs within 3 h. Moreover, photoisomerization is more efficient in winter than in late summer after sunlight irradiation for the same duration, at similar solar UV doses and with the same induction level of CPDs. These results demonstrate that seasonal differences in the UVA/UVB ratio influence the efficiency of the photoisomerization of 6-4PPs into DewarPPs.; 博士（医学）・甲第775号・令和3年3月15日; © 2020 The Authors. Photochemistry and Photobiology published by Wiley Periodicals LLC on behalf of American Society for Photobiology. This is an open access article under the terms of the Creative Commons Attribution License(https://creativecommons.org/licenses/by/4.0/), which permits use, distribution and reproduction in any medium, provided the original work is properly cited.; identifier:Photochemistry and photobiology Vol.97 No.3 p.582-588 (2021 May); identifier:00318655; identifier:http://ginmu.naramed-u.ac.jp/dspace/handle/10564/3899; identifier:Photochemistry and photobiology, 97(3): 582-588
• Source: fulltext; http://ginmu.naramed-u.ac.jp/dspace/bitstream/10564/3899/1/01%e7%94%b2775%e6%9c%ac%e6%96%87%e3%81%ae%e8%a6%81%e6%97%a8.pdf; http://ginmu.naramed-u.ac.jp/dspace/bitstream/10564/3899/2/02%e7%94%b2775%e5%af%a9%e6%9f%bb%e8%a6%81%e6%97%a8.pdf; http://ginmu.naramed-u.ac.jp/dspace/bitstream/10564/3899/3/03%e7%94%b2775%e6%9c%ac%e6%96%87.pdf
• Access Restrictions: インターネット公開
• Related Material (DOI): 10.1111/php.13361
• Periodical Title (NCID): AA00773103; https://ci.nii.ac.jp/ncid/AA00773103
• Data Provider (Database): 国立情報学研究所 : 学術機関リポジトリデータベース（IRDB）（機関リポジトリ）; https://irdb.nii.ac.jp
• Original Data Provider (Database): 奈良県立医科大学 : 奈良県立医科大学機関リポジトリ GINMU