2003 Fiscal Year Final Research Report Summary
CONTROL OF OPTIMUM pH FOR IMMOBILIZED ENZYMES
| Project/Area Number |
14550674
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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 |
Composite materials/Physical properties
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| Research Institution | NAGAOKA UNIVERSITY OF TECHNOLOGY |
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Principal Investigator |
SHIMAMURA Masato NAGAOKA UNIVERSITY OF TECHNOLOGY, FACULTY OF ENGINEERING, ASSOCIATE PROFESSOR, 工学部, 助教授 (20251853)
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| Co-Investigator(Kenkyū-buntansha) |
YAMAUCHI Takeshi NIIGATA UNIVERSITY, GRADUATE SCHOOL OF SCIENCE AND TECHNOLOGY, ASSOCIATE PROFESSOR, 大学院・自然科学研究科, 助教授 (90262477)
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| Project Period (FY) |
2002 – 2003
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| Keywords | Immobilized Enzyme / Glucose Oxidase / Magnetite / Graft Polymerization / Acrylic Acid / Acrylamide / Phenylboronic Acid / Biosensor |
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| Research Abstract |
In order to control the optimum pH for immobilized enzymes on solid supports, effects of acidic and basic groups(carboxyl and amino groups) introduced onto the supports were investigated. Magnetite particles (average particle size : 0.2μm) were used as the support, and copolymerization of acrylic acid and acrylamide was initiated from the surface of the magnetite particles to graft acrylic acid-acrylamide copolymers onto the surface. Glucose oxidase(GOx) was immobilized on the magnetite particles by condensation with carboxyl groups of the grafted copolymer. An optimum value of pH for the GOx immobilized on the copolymer-grafted magnetite was observed between that for native GOx (pH 4-5) and that for the GOx immobilized on poly(acrylic acid)-grafted magnetite (pH 7). On the other hand, although condensation of ethylenediamine or N,N-dimethylethylenediamine with the carboxyl groups on the surface of the magnetite was attempted, the amino groups introduced onto the surface were not confirmed clearly for some unknown reason. Instead, as a reference experiment, phenylboronic acid and amine were introduced simultaneously onto the surface of the magnetite to examine the effect of coexisting amino groups on the acidity index pKa of phenylboronic acid on the surface. It was found that the value of pKa was decreased by coexistent amino groups though the pKa value of the immobilized phenylboronic acid was larger than that of free one. This suggests that the optimum pH for immobilized enzymes can be controlled toward an acidic side by basic groups on the supports. The results obtained in this research present a practical technique to control the optimum pH for the immobilized enzymes on solid supports with coexistent acidic or basic groups. This technique has been applied to fabrication of enzyme-electrodes for biosensors.
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Research Products
(6 results)
