DNA and protein modification and disturbance on cell system with NO produced from photo-reactivation of N-nitrosated amino acids

N-二烷基亚硝胺的N-亚硝基部分吸收长波紫外线，N-二烷基亚硝胺的紫外光降解导致一氧化氮的释放，随后烷基自由基阳离子和活性氧物种的产生是次要事件，导致DNA链断裂、氧化和烷基化DNA损伤和突变。当365 nm的紫外光照射到N-亚硝基-脯氨酸、谷胱甘肽和酪氨酸的中性混合物中时，生成了S-亚硝基谷胱甘肽和3-硝基酪氨酸。这些结果表明，在阳光照射下，N-亚硝基丙氨酸可诱导人体细胞成分的亚硝化和硝化。

The N-nitroso moiety of N-dialkylnitrosamines absorbs UVA photons, UVA-photolysis of N-dialkylnitrosamines brings release of nitric oxide, and subsequent production of alkyl radical cations and active oxygen species follow as secondary events, which cause DNA strand breaks, oxidative and alkylative DNA damages and mutation.Photoproducts from NPRO and dA were isolated, analyzed by MS and NMR, and identified as deoxyinosine and(R)-,(S)-2-(2-pyrrolidyl)-2'-deoxyadenosine. When UV light of 365 nm was irradiated to a neutral mixture of N-nitrosoproline, gluthathione and tyrosine, S-nitrosoglutathione and 3-nitrotyrosine were generated. These results suggest that N-nitrosoproline may induce nitrosation and nitration of cellular components in humans with sunlight.