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,Photochemistry and Photobiology

当前位置： X-MOL 学术 › Photochem. Photobiol. › 论文详情

Our official English website, www.x-mol.net, welcomes your feedback! (Note: you will need to create a separate account there.)

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
Photochemistry and Photobiology ( IF 2.6 ) Pub Date : 2020-12-22 , DOI: 10.1111/php.13361
Kazuki Nishimura _{1,

2} , Hironobu Ikehata ₃ , Thierry Douki ₄ , Jean Cadet ₅ , Shigeki Sugiura ₁ , Toshio Mori _{1,

2,

6}

Affiliation

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.

中文翻译：

自然阳光 UVA/UVB 比率的季节差异影响 (6-4) 光产物光异构化为其杜瓦价异构体的效率

阳光的 UVA 和 UVB 成分可产生三类联嘧啶 DNA 光损伤 [环丁烷嘧啶二聚体 (CPD)、嘧啶 (6-4) 嘧啶酮光产物 (6-4PPs) 和相关杜瓦价异构体 (DewarPPs)]。在北半球，阳光中的UVA/UVB比率冬季高，夏季低。由于 UVB 辐射产生 6-4PP，而 UVA 辐射通过光异构化将其转化为 DewarPP，因此预计夏季和冬季 6-4PP 的光异构化可能存在差异，尽管这一点从未有过记录。为了确定这一点，在夏末和冬季将分离的 DNA 暴露在自然阳光下 8 小时，并使用校准的 ELISA 对三类光损伤的绝对水平进行定量。研究发现，阳光在DNA中以大约9:1的比例产生CPD和6-4PP，并在3小时内将大约80%的6-4PP转化为DewarPP。此外，在阳光照射相同时间、相似的太阳紫外线剂量和相同的 CPD 诱导水平后，冬季的光致异构化比夏末更有效。这些结果表明，UVA/UVB 比率的季节差异影响 6-4PP 光异构化为 DewarPP 的效率。

更新日期：2020-12-22

点击分享查看原文

点击收藏

公开下载

阅读更多本刊最新论文本刊介绍/投稿指南11