title: Physical properties of beta-N-acetyl-D-glucosaminidase and beta-N-acetyl-D-hexosaminidase from Drosophila Kc-cells.
abstract: Kc-cells from Drosophila produce two different beta-D-hexosaminidases, a beta-N-acetyl-D-glucosaminidase (E.C.3.2.1.30) and a beta-N-acetyl-D-hexosaminidase (E.C.3.2.1.52), which are also secreted into the medium. The Mr of both enzymes is about 126,000 +/- 9,700; the S-values are 8.37 +/- 0.44. Both enzymes have about the same pH optima at 5.5 and the same thermal stability. The temperature optima are identical (50 degrees C) for both enzymes if p-nitrophenyl-N-acetylglucosaminide is used as a substrate. However, when p-nitrophenyl-N-acetylgalactosaminide is used as the substrate the beta-N-acetyl-D-hexosaminidase has a temperature optimum about 10 degrees C higher. With higher salt concentrations, the activity of the beta-N-acetyl-D-glucosaminidase increases, whereas beta-N-acetyl-D-hexosaminidase is inhibited. Both enzymes also differ in their sensitivity to urea, the beta-N-acetyl-D-hexosaminidase being less sensitive than the beta-N-acetyl-D-glucosaminidase.
authors.affiliation: Institut für Zoologie, Heinrich-Heine-Universität Düsseldorf, Federal Republic of Germany.
authors.forename: U
authors.initials: U
authors.lastname: Sommer
authors.forename: K D
authors.initials: KD
authors.lastname: Spindler
mesh_terms: D000118:Acetylglucosaminidase / Q000737:chemistry* / Q000378:metabolism; D000818:Animals; D002460:Cell Line; D004331:Drosophila melanogaster / Q000166:cytology / Q000201:enzymology*; D004795:Enzyme Stability; D006863:Hydrogen-Ion Concentration; D008970:Molecular Weight; D013696:Temperature; D001619:beta-N-Acetylhexosaminidases / Q000737:chemistry* / Q000378:metabolism
chemical_list: D000118:Acetylglucosaminidase; D001619:beta-N-Acetylhexosaminidases