1997 Fiscal Year Final Research Report Summary
The mechanism of biosynthesis of plant cell walls
| Project/Area Number |
08640818
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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 |
植物生理
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| Research Institution | Saitama University |
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Principal Investigator |
TSUMURAYA Yoichi Saitama University Faculty of Science, Department of Biochemistry and Moletular Biology, Associated professor, 理学部, 助教授 (10142233)
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| Project Period (FY) |
1996 – 1997
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| Keywords | cell walls / arabinogalactan-protein / L-fucose / alpha-L-Fucosyltransferase / GDP-L-fucose / Golgi body |
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| Research Abstract |
This study is aimed to investigate the mechanism of the biosynthesis of arabinogalactan-proteins (AGPs) involved in cell walls of higher plants, and to evaluate their physiological roles concerning to tissue differentiation in relation to the organ specific expression of their sugar chains. To approach this purpose, alpha-L-fucosyltransferse (alpha-L-FucTase), an enzyme catalyzing the transfer of L-fucose (L-Fuc) residues, is focused based on its specific assay for enzyme activity and enzymatic properties, in addition to the localization of the enzyme in sub cellular organs.
1.The reaction mixture was constructed by GDP-L-Fuc as the sugar donor and and Araalpha1*3Galbeta1*6Gal derivatized with 2-aminopyridine (AGG-Pa) as the acceptor substrate together with the microsome (crude membrane) fraction as the enzyme source obtained from 6-d-old radish primary roots. After incubation at 25C,the enzyme activity was assayd by estimation of the transferred product separated by HPLC.The enzyme assay EAS also done by using GDP-L- [^<14>C] -Fuc in order to estimate the tranfer action into high molecular weight compounds.
2.The enzyme properties : The enzyme is maximally active at pH6.0-7.5 and at 25oC,and requires Zwittergent and Mn^<21> or Mg^2. The km values are estimated to be 0.08 and 3.72mM for GDP-L-Fuc and AGG-PA,respectively. Chemical and enzymatic analyzes of fucosylated AGG-PA confirmed the attachment of L-Fuc to the arabinosyl residue at 0-2 by alpha-glycosidic linkage.
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