title: Demonstration of beta-N-acetyl-D-glucosaminidase and beta-N-acetyl-D-hexosaminidase in Drosophila Kc-cells.
abstract: Kc-cells from Drosophila melanogaster, grown under serum-free conditions, produce two beta-hexosaminidases and secrete these enzymes into the medium. The two enzymes were separated by DEAE-exchange chromatography. According to their substrate specificities one enzyme is a beta-N-acetyl-D-glucosaminidase (E.C.3.2.1.30), the other one a beta-N-acetyl-D-hexosaminidase (E.C.3.2.1.52). The beta-N-acetyl-D-glucosaminidase is predominant in the medium, the beta-N-acetyl-D-hexosaminidase within the cells. The Km values for the substrates pNP-GlcNAc, pNP-GalNAc, and (GlcNAc)2 are 0.8, 16.73, and 1.67 mM for the beta-N-acetyl-D-glucosaminidase and 0.24, 0.44, and 0.2 mM for the beta-N-acetyl-D-hexosaminidase. Both enzymes are inhibited by the products and the beta-N-acetyl-D-glucosaminidase is also inhibited stereospecifically by the substrates pNP-GlcNAc and (GlcNAc)2. Both enzymes are inhibited in a partial competitive way by acetamidolactones, the Kis being as low as 0.1 microM.
authors.affiliation: Institut für Zoologie, Heinrich-Heine-Universität Düsseldorf, F.R.G.
authors.forename: U
authors.initials: U
authors.lastname: Sommer
authors.forename: K D
authors.initials: KD
authors.lastname: Spindler
mesh_terms: D000118:Acetylglucosaminidase / Q000378:metabolism*; D000818:Animals; D002460:Cell Line; D002852:Chromatography, Ion Exchange; D004331:Drosophila melanogaster / Q000166:cytology / Q000201:enzymology*; D007525:Isoelectric Focusing; D001619:beta-N-Acetylhexosaminidases / Q000378:metabolism*
chemical_list: D000118:Acetylglucosaminidase; D001619:beta-N-Acetylhexosaminidases