| Project/Area Number |
02660103
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| Research Category |
Grant-in-Aid for General Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Research Field |
応用微生物学・発酵学
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| Research Institution | University of Tsukuba |
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Principal Investigator |
KAMIYAMA Yoshi Univ. Tsukuba,Inst. Appl. Biochem.,Associate Prof., 応用生物化学系, 助教授 (60015667)
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| Co-Investigator(Kenkyū-buntansha) |
MATSUO Masaru Univ. Tsukuba,Inst. Appl. Biochem.,Assistant Prof., 応用生物化学系, 講師 (30015680)
YASUI Tsuneo Seitoku Junior College of Nutrition,Nutrition,Prof., 食品科学専攻, 教授 (50015632)
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| Project Period (FY) |
1990 – 1992
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| Project Status |
Completed (Fiscal Year 1992)
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| Budget Amount *help |
¥2,200,000 (Direct Cost: ¥2,200,000)
Fiscal Year 1992: ¥400,000 (Direct Cost: ¥400,000)
Fiscal Year 1991: ¥500,000 (Direct Cost: ¥500,000)
Fiscal Year 1990: ¥1,300,000 (Direct Cost: ¥1,300,000)
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| Keywords | beta-xylosidase / Xylooligosaccharide / xylodisaccharide Hydroysis / Condensation / Transfer reaction / 縮合・転移反応 / 反応平衝 / βーキシロシダ-ゼ / ガスクロマトグラフィ- |
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| Research Abstract |
The enzymatic and kinetic characterization of several fungal beta-xylo- sidases in the condensation reaction of xylose were investigated. The results are shown as follows.
1. beta-Xylosidases revealed the "product specificity" in the condensation reaction of xylose. The specificity of xylodisaccharide production in the condensation reaction yielded more variation for the Malbranchea pulchella enzyme (beta beta-1,1- and beta-1,4-xylodisaccharide specific enzyme) than for the Aspergillus niger enzyme etc.(broad specific enzyme) which produced all beta-xylosyl linkage.
2. Of the products, beta-1,4-xylodisaccharide was produced most in the reaction of both type enzymes. A simple mechanism with the forward(condensation) and reverse(hydrolysis) reaction was assumed and the rate constants for the forward reaction of the respective beta-linked xylodisaccharides are experimentally determined as well as the equilibrium constants. Comparison of the actual time course in the xylodisaccharide production with that the obtained by the computer simulation for this simple mechanisum implied that the reaction mechanisum of the M. pulchella enzyme comprised the condensation and hydrolysis reaction,while the mechanisum of the A. niger enzyme further includes the reaction producing xylotriose.
3. A new assay method for xylobiose-hydrolysis activity of beta-xylosidase was developed.
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