2023 Fiscal Year Research-status Report
DNA光損傷修復解明に資するO(N)量子機械学習計算法の開発と応用
| Project/Area Number |
23KJ1736
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| Research Institution | Kyushu University |
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Principal Investigator |
HUANG Xiao 九州大学, 総合理工学府, 特別研究員(DC1)
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| Project Period (FY) |
2023-04-25 – 2026-03-31
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| Keywords | polymer / ground state / excited state / bond cleavage / quantum chemical method |
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| Outline of Annual Research Achievements |
The photodegradation mechanism for polycarbonate was investigated employing the quantum chemical methods. We proposed a new polycarbonate design mechanism against photodegradation, which can be achieved by replacing the hydrogen atom on phenyl ring with the electron-withdrawing group. The results showed that the presence of electron-withdrawing groups on phenyl rings was found to regulate the bond alternation and consequently inhibits the cleavage of carbonate C-O bond of polycarbonate. In contrast, the cleavage of carbonate C-O bond of polycarbonate is facilitated by introducing the electron-donating groups on phenyl rings. This work has been published in Physical Chemistry Chemical Physics Journal (Phys. Chem. Chem. Phys., 2024, 26, 57-61).
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| Current Status of Research Progress |
Current Status of Research Progress
2: Research has progressed on the whole more than it was originally planned.
Reason
To delve deeper into the photodegradation mechanism of complex biological systems such as DNA, we employed a simplified DNA model, 5′-thymidine monophosphate, to investigate the breakage of the DNA glycosidic bond affected by ultraviolet light exposure. Owing to the relatively low energy barriers involved, we proposed two novel reaction paths for the cleavage of the DNA glycosidic bond. One path involves the direct singlet excitation, and the other path proceeds through a triplet excitation via intersystem crossing from the excited singlet state. Currently, we are in the process of preparing the manuscript, which will encompass data summarization, analysis of computational results, and drafting of the manuscript.
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| Strategy for Future Research Activity |
Based on the photodegradation mechanism of DNA damage, the calculations will be performed to identify the proper DNA repair enzyme. An examination of the interactions between the damaged DNA part and different enzyme proteins will be made, including the evaluation of binding energy and the analysis of energy decomposition, with the aim of elucidating a rational and achievable DNA repair mechanism. Combining machine learning, particularly neural network method, should facilitate the identification of suitable enzyme proteins for repairing photo-damaged DNA regions. Besides, I will prepare the presentation for domestic quantum chemistry conferences, summarize the new paper, and submit the paper to international journal.
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