Purification and characterization of beta-N-acetylgalactosaminidase from Bacillus sp. AT173-1.
Beta-N-Acetylgalactosaminidase [EC 3.2.1.53] was purified to homogeneity from the culture media of Bacillus sp. AT173-1. The enzyme has a molecular weight of 48,000 as estimated by SDS-PAGE under reducing conditions and an isoelectric point of 4.3. The enzyme requires dithiothreitol as an activator and is most active at pH 6.0. Analysis of its substrate specificity using 2-aminopyridine-labeled oligosaccharides as substrates revealed the enzyme specifically hydrolyzes beta-N-acetylgalactosaminyl linkages of GalNAcbeta1-4Galbeta1-4Glc, GalNAcbeta1-3Gal alpha1-4Galbeta1-4Glc, and N-glycans terminating with beta-N-acetylgalactosamine residues but not those with beta-N-acetylglucosamine residues. The enzyme is thus a novel beta-N-acetylgalactosaminidase with practically no beta-N-acetylglucosaminidase activity.
Tanaka
A
A
Daiwa Kasei K.K., Kosei, Shiga.
Ozaki
S
S
D001407:Bacillus / Q000201:enzymology*; D002240:Carbohydrate Sequence; D002850:Chromatography, Gel; D004229:Dithiothreitol; D004789:Enzyme Activation; D004795:Enzyme Stability; D006596:Hexosaminidases / Q000737:chemistry / Q000302:isolation & purification* / Q000378:metabolism*; D006863:Hydrogen-Ion Concentration; D007526:Isoelectric Point; D007700:Kinetics; D008969:Molecular Sequence Data; D008970:Molecular Weight; D013379:Substrate Specificity; D013439:Sulfhydryl Reagents; D013696:Temperature; D048828:beta-N-Acetyl-Galactosaminidase
D013439:Sulfhydryl Reagents; D006596:Hexosaminidases; D048828:beta-N-Acetyl-Galactosaminidase; D004229:Dithiothreitol