| Institution: | 1. Department Henan Key Laboratory of, Organic Functional Molecule and Drug Innovation, Collaborative Innovation Center of, Henan Province for Green Manufacturing of Fine Chemicals, School of Chemistry and Chemical Engineering, Key Laboratory of Green Chemical Media and Reactions, Ministry of Education, Henan Normal University, Xinxiang, Henan, 453007 P. R. China
State Key Laboratory of Cell Differentiation Regulation and Target Drug, Henan Normal University, Xinxiang, Henan, 453007 P. R. China;2. Department Henan Key Laboratory of, Organic Functional Molecule and Drug Innovation, Collaborative Innovation Center of, Henan Province for Green Manufacturing of Fine Chemicals, School of Chemistry and Chemical Engineering, Key Laboratory of Green Chemical Media and Reactions, Ministry of Education, Henan Normal University, Xinxiang, Henan, 453007 P. R. China;3. Shenzhen Key Laboratory of Synthetic Genomics, Guangdong Provincial Key Laboratory of Synthetic Genomics, CAS Key Laboratory of Quantitative Engineering Biology, Shenzhen Institute of Synthetic Biology, Shenzhen Institutes of Advanced Technology, Chinese Academy of Sciences, Shenzhen, 518055 P. R. China |
| Abstract: | Chemical- and photostability of unnatural base pairs (UBPs) are important to maintain the genetic code integrity, and critical for developing healthy semisynthetic organisms. As reported, dTPT3 was less stable upon irradiation, and thus might act as a pervasive photosensitizer to induce oxidative damage within DNA, causing harm to living semi-synthetic organisms when exposed to UVA radiation. However, there was no knowledge about molecular-level understanding of this damage process. In this paper, we not only identified four photoproducts of dTPT3, including desulfur-dTPT3 (dTPT3H), TPT3 sulphinate (TPT3SO2), TPT3 sulphonate (TPT3SO3) and TPT3-thioTPT3 (TPT3STPT3), but also established a Type II photosensitized oxidation mechanism. In addition, the antioxidant (sodium ascorbate) was able to effectively inhibit the photoproducts formation of dTPT3 and dTPT3 in DNA, suggesting that a reductive environment might protect DNA bearing dTPT3 against UVA oxidation and ameliorate its adverse biological effects. The comprehensive understanding of TPT3’ photochemical stability will give researchers helpful guidance to design more photostable UBPs and construct healthier semisynthetic organisms. |
