| Summary: | 碩士 === 國立臺灣科技大學 === 化學工程系 === 94 === Sol-gel method was employed to encapsulate D-amino acid oxidase (DAAO) and bacterial hemoglobin fused DAAO (VHb-DAAO) by using cysteamine as a catalyst at neutral pH. The sol was prepared by using TMOS. After hydrolysis and condensation of TMOS catalyzed by cysteamine for 30 min at 4 0C, a gel containing added enzymes was obtained. A glass-like solid was obtained after drying the gel at room temperature for two days. The pH and temperature stability of the DAAO were enhanced significantly after encapsulated in silica glass. Catalase was co-encapsulated with DAAO in the glass in order to remove H2O2 produced from DAAO reaction with D-amino acid. Co-encapsulated with catalase, the reaction rate of immobilized DAAO was greatly improved and so did its repeated use. Since O2 is involved in DAAO catalyzed reaction, the constant supply of O2 is required to drive the reaction to completion. Based on the reaction kinetic constants kcat of immobilized DAAO and VHb-DAAO, VHb fused with DAAO did improve the reaction rate of DAAO inside the O2 limited silica glass.
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