抄録
When Bacillus sp. K40T was cultured in the presence of L-fucose, 1, 2-α-L-fucosidase was found to be produced specifically in the culture fluid. The enzyme was purified to homogeneity from a culture containing only L-fucose by chromatography on hydroxylapatite and chromatofocusing. The molecular weight of the enzyme was estimated to be 200, 000 by gel filtration on Sephadex G-200. The enzyme was optimal at pH 5. 5-7.0 and was stable at pH 6.0-9.0. The enzyme hydrolyzed the α-(1→2)-L-fucosidic linkages in various oligosaccharides and glycoproteins such as lacto-N-fucopentaose (LNF)-I <O-α-L-fucose-(1→2)-O-β-D-galactose-(1→3)-N-acetyl-O-β-D-glucosamine-(1→3)-O-β-D-galactose-(1→4)-D-glucose>, porcine gastric mucin, and porcine submaxillary mucin. The enzyme also acted on human erythrocytes, which was confirmed by the hemagglutination test using Ulex anti-H lectin. The enzyme did not hydrolyze α-(1→3)-, α-(1→4)- and α-(1→6)-L-fucosidic linkages in LNF-III <O-β-D-galactose-(1→4)[O-α-L-fucose-(1→3)-]-N-acetyl-O-β-D-glucosamine-(1→3)-O-β-D-galactose-(1→4)-D-glucose>, LNF-II <O-β-D-galactose-(1→3)[O-α-L-fucose-(1→4)-]-N-acetyl-O-β-D-glucosamine-(1→3)-O-β-D-galactose-(1→4)-D-glucose> or 6-O-α-L-fucoPyrano-syl-N-acetylglucosamine.
