title: Urinary endo-beta-galactosidase capable of depolymerizing polylactosaminoglycans.
abstract: Human urine was found to contain an endo-beta-galactosidase capable of depolymerizing sulfated and non-sulfated polylactosaminoglycans. Using 0.05 M sodium phosphate buffer, pH 7.0, this enzyme was not retained by DEAE-Sephadex A-50 or concanavalin A-Sepharose. The urinary endo-beta-galactosidase liberated a disaccharide with chromatographic mobility identical to 6-O-sulfo-GlcNAc beta 1----3Gal as one of the major products from keratan sulfates isolated from whale nasal cartilage, bovine cornea, and human costal cartilage. It also liberated GlcNAc beta 1----3 Gal as one of the major oligosaccharides from erythroglycan. The oligosaccharide profiles produced from various keratan sulfates and erythroglycan by the action of urinary endo-beta-galactosidase are quite similar to those produced by Escherichia freundii endo-beta-galactosidase (Nakagawa, H., Yamada, T., Chien, J.-L., Gardas, A., Kitamikado, M., Li, S.-C., and Li, Y.-T. (1980) J. Biol. Chem. 255, 5955-5959). The presence of urinary endo-beta-galactosidase indicates the existence of a new catabolic pathway for polylactosaminoglycans. This pathway involves the cleavage of internal beta-galactosyl linkages of the glycan chain.
mesh_terms: D005696:Galactosidases / Q000652:urine*; D006026:Glycoside Hydrolases; D006801:Humans; D006868:Hydrolysis; D007700:Kinetics; D011134:Polysaccharides / Q000378:metabolism*; D011509:Proteoglycans / Q000378:metabolism*; D013379:Substrate Specificity; D001616:beta-Galactosidase / Q000302:isolation & purification / Q000652:urine*
chemical_list: D011134:Polysaccharides; D011509:Proteoglycans; C042947:polylactosamino-proteoglycan; D005696:Galactosidases; D006026:Glycoside Hydrolases; C026093:keratan-sulfate endo-1,4-beta-galactosidase; D001616:beta-Galactosidase