Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:3.2.1.31 (beta-glucuronidase)
 7,680 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Fibroblasts were incubated in the presence of the anti-microtubular drugs colchicine, vinblastine and vincristine. In concentrations between 10nm and 1 mM these drugs stimulated the secretion of beta-N-acetylglucosaminidase, alpha-N-acetylglucosaminidase and beta-glucuronidase, but not of beta-galactosidase. The endocytosis of beta-N-acetylhexosaminidase and alpha-N-acetylglucosaminidase, but not of beta-glucuronidase, was inhibited at drug concentrations higher than 0.1 micrometer. Formation, secretion and association with the cell membrane of sulphated proteoglycans were not affected by anti-microtubular drugs. Endocytosis of sulphated proteoglycans and their subsequent degradation was inhibited by drug concentrations above 0.1 micrometer. The inhibition of intracellular glycosaminoglycan degradation led to a moderate storage of these compounds. These results suggest that microtubules participate in the control of secretion and endocytosis of lysosomal enzymes, and in the endocytosis and degradation of lysosomal substrates such as sulphated proteoglycans.
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PMID:Studies on secretion and endocytosis of macromolecules by cultivated skin fibroblasts. Effects of anti-microtubular agents on secretion and endocytosis of lysosomal hydrolases and of sulphated glycosaminoglycans. 63 45

Adsorptive endocytosis of five different lysosomal enzymes from various human and non-human sources was susceptible to inhibition by mannose and l-fucose, methyl alpha-d-mannoside, alpha-anomeric p-nitrophenyl glycosides of mannose and l-fucose, mannose 6-phosphate and fructose 1-phosphate. A few exceptions from this general scheme were observed for particular enzymes, particularly for beta-glucuronidase from human urine. The inhibition of alpha-N-acetylglucosaminidase endocytosis by mannose, p-nitrophenyl alpha-d-mannoside and mannose 6-phosphate was shown to be competitive. The loss of endocytosis after alkaline phosphatase treatment of lysosomal enzymes supports the hypothesis that the phosphorylated sugars compete with a phosphorylated carbohydrate on the enzymes for binding to the cell-surface receptors [Kaplan, Achord & Sly (1977) Proc. Natl. Acad. Sci. U.S.A.74, 2026-2030]. Endocytosis of ;low-uptake' forms of alpha-N-acetylglucosaminidase and alpha-mannosidase was likewise susceptible to inhibition by sugar phosphates and by alkaline phosphatase treatment, suggesting that ;low-uptake' forms are either contaminated with ;high-uptake' forms or are internalized via the same route as ;high-uptake' forms. The existence of an alternative route for adsorptive endocytosis of lysosomal enzymes is indicated by the unaffected adsorptive endocytosis of rat liver beta-glucuronidase in the presence of phosphorylated sugars and after treatment with alkaline phosphatase.
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PMID:Evidence for lysosomal enzyme recognition by human fibroblasts via a phosphorylated carbohydrate moiety. 64 6

A simple, automated colorimetric microassay system has been designed to quantitate enzyme activities commonly used as markers for subcellular compartments. This system relies on the spectrophotometric reading of microtiter wells containing the chromophore products. The microassay allows rapid, economical, and quantitative analysis of enzyme activities associated with sucrose or Percoll gradient fractions used for subcellular fractionation studies as well as the screening of a large number of fractions derived from HPLC and other separation columns used for enzyme purification. We describe its use for the quantitation of activities associated with acid and alkaline phosphatases, alkaline phosphodiesterase, beta-glucuronidase, alpha-N-acetylglucosaminidase, alpha-mannosidase, alpha-L-fucosidase, glycosidases, serine esterases, and succinate dehydrogenase, and give the range of their sensitivities. This microassay system has been applied to the isolation of granules of cytolytic lymphocytes and to the identification and purification of a serine esterase from the isolated granules of these cells.
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PMID:Analysis of enzymatic activities of subcellular and chromatographic fractions by an automated colorimetric microassay system. 349 54

Phosphomannosyl residues on acid hydrolases serve as recognition markers which target these enzymes to lysosomes. We have found that the oligosaccharide units of newly synthesized beta-glucuronidase contain phosphate residues in diester linkage between mannose and alpha-linked N-acetylglucosamine residues (Tabas, I., and Kornfeld, S. (1980) J. Biol. Chem. 255, 6633--6639). To obtain larger amounts of these molecules for structural studies, total cellular glycopeptides were isolated from [2-3H]mannose-labeled mouse lymphoma cells, and the phosphorylated oligosaccharides were released by endo-beta-N-acetylglucosaminidase CII and H and isolated by gel filtration and ion exchange chromatography. The fractions were characterized by alpha-mannosidase digestion before and after removal of the phosphate residues and by acetolysis. We also determined whether the phosphate was present as a phosphomonoester or as a diester. The phosphorylated oligosaccharides consisted of a family or related molecules, all of which contained a high mannose-type oligosaccharide core. The major class consisted of isomers containing a single phosphate in diester linkage to 1 of 3 mannose residues of the underlying oligosaccharide. The second class contained isomers with two phosphodiester groups located at five different positions of the oligosaccharide. In both of these classes, the phosphodiester group could be converted to a phosphomonoester by pig liver alpha-N-acetylglucosaminidase, indicating that the cover is alpha-linked N-acetylglucosamine. The third class was similar to the second except that the 2 phosphate residues were present as monoester groups. The last class contained molecules with a single phosphomonoester group. These molecules differed from those with single phosphodiester groups in that the core oligosaccharides were smaller. This is consistent with their being more mature species which have undergone partial processing. These data demonstrate that phosphorylation can occur at 5 separate mannose residues on the high mannose-type oligosaccharides. Individual molecules can have 1, 2, and perhaps even 3 phosphate residues. The majority of the newly synthesized phosphorylated oligosaccharides contain phosphate groups in diester linkage.
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PMID:Structural studies of phosphorylated high mannose-type oligosaccharides. 743 Jan 58

The characterization and properties of a beta-galactanase and alpha- and beta-galactosidases as well as heparan sulfate and chondroitin sulfate degrading enzymes which appear during the 15 days of the embryonic development of the mollusc Pomacea sp. is reported. The beta-galactanase, which appears around day 7 of development, was separated from alpha- and beta-galactosidase which emerge at day 1 and 4 after oviposition, respectively. The galactanase seems to be responsible for the degradation of an acidic beta-galactan (which is also synthesized by the eggs around day 5) to galactose and di- and tri-galactosides. Heparan sulfate appears around day 10 of development together with a heparan sulfate endoglucuronidase responsible for the degradation of its N-acetylated region. An alpha-N-acetylglucosaminidase and a beta-glucuronidase which act upon the N-acetylated fragments formed from heparan sulfate emerge around day 4 of development. Chondroitin sulfate and a chondroitin sulfate sulfatase emerge around day 9 of development whereas a beta-N-acetylgalactosaminidase and the beta beta-galactan, heparan and chondroitin sulfate, respectively. The possible role of these elements in the migration of mesenchymal cells, in the processes of cell-cell recognition and control of cell growth is discussed.
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PMID:Appearance and fate of a beta-galactanase, alpha, beta-galactosidases, heparan sulfate and chondroitin sulfate degrading enzymes during embryonic development of the mollusc Pomacea sp. 806 9

1. The disaccharide sequences of a heparan sulfate isolated from Anomantidae sp. was determined with the aid of heparitinase I, heparitinase II from Flavobacterium heparinum, mollusc beta-glucuronidase and alpha-N-acetylglucosaminidase besides nitrous acid degradation and chemical analyses. 2. Like the mammalian heparan sulfates the mollusc heparan sulfate is composed of different oligosaccharide blocks of N-acetylated disaccharides, N-sulfated disaccharides and N,6-sulfated disaccharides and has in its nonreducing end the monosaccharide glucosamine 2,6-disulfate. 3. The oligosaccharides produced by heparitinase I degradation contain at their reducing ends a N-acetylated, 6-sulfated disaccharide. 4. These and other results lead to the conclusion that the general structure of the heparan sulfate is maintained through evolution.
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PMID:Structure of heparan sulfate from the fresh water mollusc Anomantidae sp: sequencing of its disaccharide units. 822 65