1999 Fiscal Year Final Research Report Summary
The physiochemical research of highly active and streoselective plastic enzyme invention
| Project/Area Number |
09450317
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| Research Category |
Grant-in-Aid for Scientific Research (B)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
工業物理化学
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| Research Institution | KYOTO UNIVERSITY |
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Principal Investigator |
OHKUBO Katsutoshi Kyoto University, Institute of Advanced Energy, Professor, エネルギー理工学研究所, 教授 (00040402)
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| Co-Investigator(Kenkyū-buntansha) |
KODAKI Tutomu Kyoto University, Institute of Advanced Energy, Asistant prof., エネルギー理工学研究所, 助教授 (70170264)
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| Project Period (FY) |
1997 – 1999
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| Keywords | plastic enzyme / amino acid ester / transition-state analogue / hydrolysis / oxygenesis / template / stereoselection / 立体選択 |
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| Research Abstract |
Based on this Grant-in-Aid for Scientific Research (B), the am phipthic plastic enzymes possessing high acivity and substrate-stereoselectivity were constructed with a particular reference to artificial enzyme action of esterase and mono-or dioxygenase. The active sites of plastic esterase and oxygenase enzymes were supplied by N-acryloyl-L-histidine and N-acryloyl-L-histidine-attached iron (II or III) porphirin, respectively. The stereoselective function of the above plastic enzymes was expected by the action of the L-histidine part in the active site. In the case of the former (plastic esterase), the stereoselective hydrolysis of a target substrate (L-leucine P-nitrophenolate) was performed by taking as a typical example, as follows : plastic esterase was synthsized by the polymerization of the active-site monomer (which combines with the transition-state analogue template of racemic 1- (benzy oxycarbonylamino) isobutylphosphonic acid mono-p-nitrophenyl ester before the polym erization), acrylamido-type monomer and cross-linker, ammnoum-type acrylamido deribative and/or hydrophobic styrene. In regard to the catalytic and stereoselective activitries for the plastic esterase, the hydrolysis reaction progressed at the speed over the double with the 89%e. e. of the L-leucine substrate, as compared with the L-histidine monomer catalyst exhibiting low stereoselectivity. On the other hand, the plastic dioxygenase (prepared similarly with N-acryloyl-L-histidine-attached iron (II or III) porphirin and the above-mentioned monomers used for the polymer framework) demonstrated 98%selectivity for the hydroxylation of styrene and 53%selectivity for the ring-opening dioxygenolysis of tryptophane derivatives. Thus, fundamental research of plastic enzymes was established in the mimetic chemistry of heme-and nonheme enzymes
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