Isolation and characterization of an endo-beta-galactosidase from a new strain of Escherichia freundii.
A new strain of Escherichia freundii was isolated from human feces. Compared with the previous strain (Kitamikado, M., and Ueno, R. (1970) Bull. Jpn. Soc. Sci. Fish. 36, 1175-1180), this strain releases comparable levels of endo-beta-galactosidase with lower levels of exoglycosidases in the culture medium containing 0.3% of keratan sulfate. Endo-beta-galactosidase was purified by an improved purification procedure involving Amicon H1P10 hollow fiber filtration, QAE-Sephadex A-50, and CM-Sephadex C-50 chromatographies. The purified enzyme is completely free from proteases and exoglycosidases. The general properties of this enzyme are: molecular weight, 28,000; optimal pH, 5.5 TO 5.8; PI, pH 8.0. This enzyme hydrolyzed keratan sulfates isolated from different sources to produce 6-O-sulfo-GlcNAc beta1 leads to 3Gal as the major product. In addition, the specificity of this enzyme toward various glycoconjugates was also studied.
D000818:Animals; D002236:Carbohydrate Conformation; D004925:Escherichia / Q000201:enzymology*; D005243:Feces; D005696:Galactosidases / Q000378:metabolism*; D006028:Glycosphingolipids; D006801:Humans; D008892:Milk; D008970:Molecular Weight; D009844:Oligosaccharides; D013379:Substrate Specificity; D001616:beta-Galactosidase / Q000302:isolation & purification / Q000378:metabolism*
D006028:Glycosphingolipids; D009844:Oligosaccharides; D005696:Galactosidases; D001616:beta-Galactosidase