排序方式: 共有4条查询结果,搜索用时 15 毫秒
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Kohsuke Honda Michihiko Kataoka Sakayu Shimizu 《Biotechnology and Bioprocess Engineering》2002,7(3):130-137
Microbial lactonohydrolases (intramolecular ester bond-hydrolyzing enzymes) with unique properties were found. The lactonohydrolase
fromFusarium oxysporum catalyzes enantioselective hydrolysis of aldonate lactones andd-pantoyl lactone (d-PL). This enzyme is useful for the large-scale optical resolution of racemic PL. TheAgrobacterium tumefaciens enzyme catalyzes asymmetric hydrolysis of PL, but the stereospecificity is opposite to that of theFusarium enzyme. Dihydrocoumarin hydrolase (DHase) fromAcinetobacter calcoaceticus is a bifunctional enzyme, which catalyzes not only hydrolysis of aromatic lactones but also bromination of monochlorodimedon
in the presence of H2O2 and dihydrocoumarin. DHase also hydrolyzes several linear esters, and is useful for enantioselective hydrolysis of methyldl-β-acetylthioisobutyrate and regioselective hydrolysis of methyl cetraxate. 相似文献
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A Model Transgenic Cereal Plant with Detoxification Activity for the Estrogenic Mycotoxin Zearalenone 总被引:7,自引:0,他引:7
Higa-Nishiyama A Takahashi-Ando N Shimizu T Kudo T Yamaguchi I Kimura M 《Transgenic research》2005,14(5):713-717
Zearalenone (ZEN) is an estrogenic mycotoxin produced by the necrotrophic cereal pathogen Fusarium graminearum. This mycotoxin is detoxified by ZHD101, a lactonohydrolase from Clonostachys rosea, or EGFP:ZHD101, its fusion to the C-terminus of an enhanced green fluorescence protein. We previously showed that egfp:zhd101 is efficiently expressed in T0 leaves of rice. In this study, we assessed the feasibility of in planta detoxification of the mycotoxin using progeny. When protein extract from T1 leaves was incubated with ZEN, the amount of the toxin decreased significantly as measured by HPLC. ZEN degradation activity
was also detected in vivo in transgenic T2 seeds. These results suggest that zhd101 can be exploited as an efficient and cost-effective system for protection of important cereals that are more susceptible
to the pathogen (e.g., wheat and maize) from contamination with the estrogenic mycotoxin. 相似文献
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Michihiro Sugano Munehiko Yamamoto 《Bioscience, biotechnology, and biochemistry》2013,77(6):1255-1256
Chemical changes in lysozyme during heating at 150~250°C for 20min were investigated by means of IR, ESR, and CD spectroscopies and gel permeation chromatography, and further a tryptic hydrolysate from the lysozyme heated at 200°C was analyzed by ion exchange chromatography. At 150°C, polymerization through disulfide linkages was observed, and at180°C, both polymerization and degradation occurred. When the temperature was raised to 200°C, remarkable changes in the structure of lysozyme, such as cleavage and recombination of peptide bonds, occurred. Over 200°C, polymerization and degradation occurred more violently. 相似文献
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微生物酶拆分方法生产D-泛酸的手性中间体D-泛解酸内酯 总被引:13,自引:0,他引:13
筛选到一株产D-泛解酸内酯水解酶的串珠镰孢霉菌(Fusarium moniliforme SW-902)。产酶条件研究表明,用甘油作碳源,蛋白胨作氮源,初始pH8.0,温度26℃,摇瓶培养3d,产酶量最高。在60L和1000L发酵罐中通风发酵45-47h,产酶量为6-8g干菌体/L,D-泛解酸内酯水解酶酶活力达到0.87-0.92IU/g干菌体。该酶的最适反应温度为55℃,最适反应pH为7.0-7.5。在酶不对称水解泛解酸内酯过程中,对溶液加酶量5%-10%,底物浓度10%-20%,控制水解率20%-30%,水解效果最好。 相似文献
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