| Project/Area Number |
10650844
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| Research Category |
Grant-in-Aid for Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
Synthetic chemistry
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| Research Institution | Tokyo Institute of Technology |
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Principal Investigator |
IKEDA Hiroshi Tokyo Institute of Technology, Graduate School of Bioscience and Biotechnology, Assistant Professor, 大学院・生命理工学研究科, 助手 (70201910)
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| Project Period (FY) |
1998 – 2001
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| Project Status |
Completed (Fiscal Year 2001)
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| Budget Amount *help |
¥3,800,000 (Direct Cost: ¥3,800,000)
Fiscal Year 2001: ¥400,000 (Direct Cost: ¥400,000)
Fiscal Year 2000: ¥500,000 (Direct Cost: ¥500,000)
Fiscal Year 1999: ¥500,000 (Direct Cost: ¥500,000)
Fiscal Year 1998: ¥2,400,000 (Direct Cost: ¥2,400,000)
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| Keywords | Supermolecule / Artificial Enzyme / Cyclodextrin / Cooperative Effect / Regulation of Activity / Hydrolase / アロステリック / クラウンエーテル / 分子認識 / ベンゾイン縮合 |
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| Research Abstract |
Natural enzymes have mechanisms to control their activities in response to the concentration of substrates, products or other effectors. In contrast, there have not been many reports of artificial enzymes that have mechanisms to control their activities, although many successful artificial enzymes with high catalytic activity or high substrate selectivity have been reported. Thus, an important area of research in the field of supramolecular chemistry is the development of chemical methods to control the activities of artificial enzymes.
In this project, we constructed new supramolecular assembles having regulation systems, such as an allosteric system.
1) We prepared cyclodextrin dimer (designated βCβH) that has a catalytic site located between two β-cyclodextrins and acts as an artificial hydrolase. βCβH shows homotropic allosteric-like effect.
2) Artificial holoenzymes for benzoin condensation were synthesized using thiazolio-appended β-cyclodextrin dimers. The dimer with an L-aspartic acid residue as a linker for connecting two β-cyclodextrin units caused 26-fold acceleration in the benzoin condensation, whereas the dimer with the linker of a L-glutamic acid residue caused only 7-fold acceleration, indicating that the linker length of the dimer is an important factor in this artificial holoenzyme.
3) β-cyclodextrin derivatives bearing a benzo-crown moiety at the primary- or secondary-hydroxy side were synthesized for molecular recognition toward tryptophan (Trp) in zwitterionic form. The secondary-hydroxy side modification was preferable to the primary-hydroxy side one for recognition of Trp, because the ammonium cation part of Trp was located at the secondary-hydroxy side of the cyclodextrin.
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