| 研究課題/領域番号 |
20K05506
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| 研究機関 | 東京大学 |
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研究代表者 |
中村 優希 東京大学, 大学院総合文化研究科, 助教 (70732676)
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| 研究期間 (年度) |
2021-02-01 – 2024-03-31
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| キーワード | Heterogeneous Catatalyst / Enzyme / Mesoporous Silica / C-C Bond Cleavage / Degradation |
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| 研究実績の概要 |
In this research, an enzyme will be immobilized inside the chemically modified mesoporous silica to enhance both its stability and reactivity. The enzyme of interest in this work is protocatechuate 3,4-dioxygenase, which can selectively cleave a strong C-C bond of catechol aromatic rings.
In year 2021 and 2022, preparation of mesoporous silica and modification of its surface using silane coupling agent were achieved. As a choice of mesoporous silica, SBA-15 was synthesized, instead of MCM-41. This was due to the fact that (1) the protocol of its synthesis was well-established in the Ogura lab, the group where this research was carried out, (2) SBA-15 has a similar pore structure as MCM-41 with controlled pore size, and (3) SBA-15 is known to possess high SiOH density on its surface, which allows the easy surface modification to tune the immobilization interactions between its surface and target enzymes.
The SBA-15 prepared in three different average pore sizes of 8 nm, 10 nm, and 12 nm were subjected to surface modification by silane coupling to obtain the modified SBA-15, m-SBA-15.To prove the stabilizing effect of the unstable enzyme via immobilization into mesoporous silica, a more commonly and widely used enzyme compared to protocatechuate 3,4-dioxygenase, lipase, was immobilized first into m-SBA-15. As a result, the increase in stability of lipase was successfully observed through immobilization into m-SBA-15. Moreover, methods to measure its enzymatic activity and quantification of active lipase were established, and optimized pore size for immobilization was explored.
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| 現在までの達成度 (区分) |
現在までの達成度 (区分)
3: やや遅れている
理由
The progress of the research is slightly delayed. This is due to the fact that the synthesis of MCM-41 with large pore size required special techniques, which turned out to be not as straightforward as originally expected. To solve this issue, more suitable choice of mesoporous silica, SBA-15, was selected as a substitute material for its (1) well-established synthetic protocols at Ogura lab, where this research was carried out, (2) similar structure as MCM-41, and (3) high SiOH density on its surface, which allows the easy surface modification to tune the immobilization interactions between its surface and target enzymes.
In addition, immobilization of enzyme into mesoporous silica turned out to require careful handling techniques due to its unstable nature. To establish the proper techniques to treat unstable enzymes, the research project of well-studied lipase was carried out before the immobilization of protocatechuate 3,4-dioxygenase, as indicated in the summary.
Through this approach, acquired protocols for treating lipase can be applied to the immobilization of protocatechuate 3,4-dioxygenase from year 2023, which will result in smooth transition of the research.
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| 今後の研究の推進方策 |
In year 2023, completion of lipase immobilization project as well as exploration of protocatechuate 3,4-dioxygenase immobilization project will be carried out.
First, immobilized lipase will be utilized to explore its stability and reaction efficiency in details. At the same time, immobilization of protocatechuate 3,4-dioxygenase will be explored by applying the acquired protocols for handling unstable enzymes from the lipase project.
During this transition, adjustment of the established protocols will be examined by optimizing reaction conditions for immobilization of protocatechuate 3,4-dioxygenase, which includes the screening of mesoporous silica as well as silane coupling agents for surface modifications.
Once the protocatechuate 3,4-dioxygenase is successfully immobilized into the right choice of mesoporous silica, the obtained material will be used to explore the degradation reactions of catechol moieties via C-C bond activation of aromatic rings.
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| 次年度使用額が生じた理由 |
The amount of grant to be used in the next fiscal year in year 2022 was 7,729 yen. This was mainly due to the fact that many of the conferences were held online or hybrid instead of on-site, which reduced the travel expenses to 0 yen.
Also, the fact that I am currently pregnant with a second child made traveling difficult.
In the next fiscal year, more expense is expected to be used as travel expenses.
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