J. Biol. Chem.

N-Acetylglucosamine-1-phosphodiester alpha-N-acetylglucosaminidase (phosphodiester alpha-GlcNAcase) has been purified 3,000-fold from bovine liver and its kinetic properties determined as described in the previous report (Mullis, K. G., Huynh, M., and Kornfeld, R. (1993) J. Biol. Chem. 269, 1718-1726). This report describes the hydrodynamic and lectin binding properties of phosphodiester alpha-GlcNAcase as well as its intracellular localization. The molecular weight of phosphodiester alpha-GlcNAcase is 204,950, as determined from density gradient centrifugation in D2O and H2O glycerol gradients and gel filtration. Enzymatically active enzyme migrates on sodium dodecyl sulfate-polyacrylamide gel electrophoresis with a molecular weight of 129,000, consistent with native phosphodiester alpha-GlcNAcase being a dimer. The lectin binding properties of phosphodiester alpha-GlcNAcase indicate that it contains sialylated species of both complex type N-linked oligosaccharides and O-linked oligosaccharides. In immunofluorescence studies phosphodiester alpha-GlcNAcase shows a perinuclear, Golgi localization in Vero cells as does the mid-Golgi marker alpha-mannosidase II. After exposure of the Vero cells to brefeldin A, phosphodiester alpha-GlcNAcase assumes an endoplasmic reticulum staining pattern. In contrast, in cells costained with the trans-Golgi marker wheat germ agglutinin, the wheat germ agglutinin marker assumed an endosomal network appearance after exposure to brefeldin A. These findings indicate that phosphodiester alpha-GlcNAcase is normally located within the Golgi stack, separate from the trans-Golgi and trans-Golgi network stained by wheat germ agglutinin.

Source:http://purl.uniprot.org/citations/8294421