| Literature DB >> 12036080 |
Masayuki Okuyama1, Haruhide Mori, Kotomi Watanabe, Atsuo Kimura, Seiya Chiba.
Abstract
Replacement of the catalytic nucleophile Asp481 by glycine in Schizosaccharomyces pombe alpha-glucosidase eliminated the hydrolytic activity. The mutant enzyme (D481G) was found to catalyze the formation of an alpha-glucosidic linkage from beta-glucosyl fluoride and 4-nitrophenyl (PNP) alpha-glucoside to produce two kinds of PNP alpha-diglucosides, alpha-isomaltoside and alpha-maltoside. The two products were not hydrolyzed by D481G, giving 41 and 29% yields of PNP alpha-isomaltoside and alpha-maltoside, respectively. PNP monoglycosides, such as alpha-xyloside, alpha-mannoside, or beta-glucoside, acted as the substrate, but PNP alpha-galactoside and maltose could not. No detectable product was observed in the combination of alpha-glucosyl fluoride and PNP alpha-glucoside. This study is the first report on an "alpha-glycosynthase"-type reaction to form an alpha-glycosidic linkage.Entities:
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Year: 2002 PMID： 12036080 DOI： 10.1271/bbb.66.928
Source DB: PubMed Journal: Biosci Biotechnol Biochem ISSN： 0916-8451 Impact factor: 2.043