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| | ONLINE | ISSN | : | 1347-6947 | | PRINT | ISSN | : | 0916-8451 |
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| | Bioscience, Biotechnology, and Biochemistry |
| Vol. 64 (2000) , No. 12 pp.2530-2537 |
| [Image PDF (1307K)] [References]  |
 | Gene Cloning and Characterization of α-Glucuronidase of Bacillus stearothermophilus No. 236
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| | | 1) Graduate School of Biotechnology, Korea University |
| (Received January 17, 2000)
(Accepted June 28, 2000)
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| | The α-glucuronidase gene of Bacillus stearothermophilus No. 236 was cloned, sequenced, and expressed in Escherichia coli. The gene, designated aguA, encoded a 691-residue polypeptide with calculated molecular weight of 78,156 and pI of 5.34. The α-glucuronidase produced by a recombinant E. coli strain containing the aguA gene was purified to apparent homogeneity and characterized. The molecular weight of the α-glucuronidase was 77,000 by SDS-PAGE and 161,000 by gel filtration; the functional form of the α-glucuronidase therefore was dimeric. The optimal pH and temperature for the enzyme activity were pH 6.5 and 40°C, respectively. The enzyme's half-life at 50°C was 50 min. The values for the kinetic parameters of Km and Vmax were 0.78 mM and 15.3 U/mg for aldotriouronic acid [2-O-α- (4-O-methyl-α-D-glucopyranosyluronic)-D-xylobiose]. The α-glucuronidase acted mainly on small substituted xylo-oligomers and did not release methylglucuronic acid from intact xylan. Nevertheless, synergism in the release of xylose from xylan was found when α-glucuronidase was added to a mixture of endoxylanase and β-xylosidase.
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| To cite this article: | | Il-Dong CHOI, Hwa-Young KIM and Yong-Jin CHOI, “Gene Cloning and Characterization of α-Glucuronidase of Bacillus stearothermophilus No. 236”, Biosci. Biotechnol. Biochem., Vol. 64, 2530-2537 (2000) . | |
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| doi:10.1271/bbb.64.2530 | | JOI JST.JSTAGE/bbb/64.2530 |
| Copyright (c) 2005 by Japan Society for Bioscience, Biotechnology, and Agrochemistry |
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