| Project/Area Number |
11450311
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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 |
生物・生体工学
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| Research Institution | TOKYO INSTITUTE OF TECHNOLOGY |
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Principal Investigator |
OKAHATA Yoshio TOKYO INSTITUTE OF TECHNOLOGY, GRADUATE SCHOOL OF BIOSCIENCE AND BIOTECHNOLOGY, PROFESSOR, 大学院・生命理工学研究科, 教授 (80038017)
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| Co-Investigator(Kenkyū-buntansha) |
MORI Toshiaki TOKYO INSTITUTE OF TECHNOLOGY, GRADUATE SCHOOL OF BIOSCIENCE AND BIOTECHNOLOGY, ASSOCIATE, 大学院・生命理工学研究科, 助教授 (50262308)
佐藤 智典 東京工業大学, 生命理工学部, 助教授 (00162454)
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| Project Period (FY) |
1999 – 2000
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| Project Status |
Completed (Fiscal Year 2000)
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| Budget Amount *help |
¥14,200,000 (Direct Cost: ¥14,200,000)
Fiscal Year 2000: ¥4,200,000 (Direct Cost: ¥4,200,000)
Fiscal Year 1999: ¥10,000,000 (Direct Cost: ¥10,000,000)
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| Keywords | Supercritical Fluid / Lipid-coated Enzyme / Furuorofolm / Transglycosylation / 脂質修飾酵素 / ガラクトシダーゼ |
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| Research Abstract |
Supercritical fluids (scFs) have been attractive as media for enzymatic reactions, as well as other chemical reactions and media for extraction. Because their physical properties can be manipulated by small changes in pressure and temperature, and several of these properties (e.g., density, diffusiveness, and viscosity) are intermediate between those of gas and liquid. The larger diffusiveness in scF compared to a liquid can be expected to increase the reaction rate.
In this report, we report the high catalytic activity of a lipid-coated b-galactosidase for transgalactosylation to alcohols in supercritical fluorofolm (scCHF3). Typical results are stummarized in the figure. A lipid-coated b-galactosidase can catalyse the transgalactosylation from p-nitrophenyl galactopyranoside to 5-phenylpentanol in sufficient efficiency in organic solvents, however the enzyme easily denatured and both the initial rate νo and the conversion decreased drastically in polar solvents above chloroform (the left figure). On the contrary, in the supercritical CHF3, the νo of the reaction increased 20 times compared with those in organic solvents (the right figure). The νo could be reversibly controlled by changing the pressure of supercritical fluid from 1 to 150 atm, and the conversion was almost constant, This means that the reactivity of a lipid-coated enzyme cam be reversibly controlled without denaturation in supercritical fluid by changing pressure (polarity). This is the first example to control enzyme reactions in supercritical fluids.
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