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)

This study describes effects of sulphasalazine, 5-amino-salicylic acid (5-ASA) and sulphapyridine on polymorphonuclear neutrophils. Chemotaxis by polymorphonuclear neutrophils incubated with 5-ASA was reduced in a concentration dependent fashion (10(-5)-10(-4) M). Degranulation and release of lysozyme and beta-glucuronidase by activated polymorphonuclear neutrophils was inhibited by sulphasalazine but inhibited by sulphasalazine (IC50: 2 x 10(-4) M) and to a lesser extent by 5-ASA (IC50: 10(-3) M). Using a cell-free system sulphasalazine was found to be a strong scavenger and 5-ASA and sulphapyridine had only weak effects. Superoxide anion production requires translocation of a cytochrome b-245 and this translocation was reduced by sulphasalazine (P less than 0.01) but not by 5-ASA or sulphapyridine. In conclusion, the intact sulphasalazine molecule has an action of its own and marked differences exist between the action of sulphasalazine and 5-ASA, which may be important for the clinical activity.
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PMID:Effects of sulphasalazine and its metabolites on neutrophil chemotaxis, superoxide production, degranulation and translocation of cytochrome b-245. 168 23

Rat liver microsomal fractions have been equilibrated in various types of linear density gradients. 15 fractions were collected and assayed for 27 constituents. As a result of this analysis microsomal constituents have been classified, in the order of increasing median density, into four groups labeled a, b, c, and d. Group a includes: monoamine oxidase, galactosyltransferase, 5'-nucleotidase, alkaline phosphodiesterase I, alkaline phosphatase, and cholesterol; group b: NADH cytochrome c reductase, NADPH cytochrome c reductase, aminopyrine demethylase, cytochrome b(5), and cytochrome P 450; group c: glucose 6-phosphatase, nucleoside diphosphatase, esterase, beta-glucuronidase, and glucuronyltransferase; group d: RNA, membrane-bound ribosomes, and some enzymes probably adsorbed on ribosomes: fumarase, aldolase, and glutamine synthetase. Analysis of the microsomal fraction by differential centrifugation in density gradient has further dissociated group a into constituents which sediment more slowly (monoamine oxidase and galactosyltransferase) than those of groups b and c, and 5'-nucleotidase, alkaline phosphodiesterase I, alkaline phosphatase, and the bulk of cholesterol which sediment more rapidly (group a2). The microsomal monoamine oxidase is attributed, at least partially, to detached fragments of external mitochondrial membrane. Galactosyltransferase belongs to the Golgi complex. Group a2 constituents are related to plasma membranes. Constituents of groups b and c and RNA belong to microsomal vesicles derived from the endoplasmic reticulum. These latter exhibit a noticeable biochemical heterogeneity and represent at the most 80% of microsomal protein, the rest being accounted for by particles bearing the constituents of groups a and some contaminating mitochondria, lysosomes, and peroxisomes. Attention is called to the operational meaning of microsomal subfractions and to their cytological complexity.
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PMID:Analytical study of microsomes and isolated subcellular membranes from rat liver. 3. Subfractionation of the microsomal fraction by isopycnic and differential centrifugation in density gradients. 415 Apr 90

Isopycnic equilibration and sedimentation rate studies of rat liver microsomes led previously to the assignment of microsomal constituents into group a1 (monoamine oxidase), group a2 (5'-nucleotidase, alkaline phosphodiesterase I, alkaline phosphatase and cholesterol), group a3 (galactosyltransferase), group b (NADH cytochrome c reductase, NADPH cytochrome c reductase, aminopyrine demethylase, cytochrome b(5) and P 450), and group c (glucose 6-phosphatase, esterase, nucleoside diphosphatase, beta-glucuronidase and glucuronyltransferase). Confirmation and extension of the assignment into groups has been obtained by studying the differential effect of the reagents digitonin, EDTA, and PPi. Digitonin specifically affected the equilibrium density only of the group a2 and (to a lesser extent) group a3, and not of groups b and c under conditions which preserved the structure-linked latency of nucleoside diphosphatase and galactosyltransferase. Within experimental error the rate of sedimentation of all microsomal constituents was unaffected. The morphological appearance under the electron microscope was indistinguishable from that of nondigitonin-treated microsomes, except that a few smooth membranes (< 10%) exhibited broken-looking profiles. Treatment of microsomes with EDTA or PPi detached a substantial part of RNA and released protein in excess over the amount accountable for by detachment of ribosome constituents. This detachment was confirmed by electron microscopy. EDTA and PPi decreased markedly the equilibrium density and the density dispersion of groups b and c, due mainly to the uncoating of rough elements. EDTA and PPi shifted slightly the distribution profiles of groups a towards lower densities, possibly as a result of the release of adsorbed proteins. The combination of EDTA and digitonin, used subsequently, rendered the average equilibrium density of group a2 higher than that of groups b and c. Dense subfractions were thus enriched in constituents of group a2 and showed mainly broken-looking vesicles under the electron microscope. The import of our results on the biochemical and enzymic properties of the subcellular components of the microsome fractions is discussed.
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PMID:Analytical study of microsomes and isolated subcellular membranes from rat liver. IV. Biochemical, physical, and morphological modifications of microsomal components induced by digitonin, EDTA, and pyrophosphate. 436 10

The subcellular distribution of cytochrome b and ubiquinone in resting human neutrophils was investigated by rate zonal sedimentation of postnuclear supernatants on continuous sucrose gradients. Both cytochrome b and ubiquinone were mainly localized in small organelles, tertiary granules, that were resolved from the specific and azurophilic granules as well as from the cell membrane fraction. This cytochrome b- and ubiquinone-rich granule was shown to contain dicyclohexylcarbodiimide (DCCD)-sensitive, Mg2+-dependent ATPase as well as low amounts, less than a third, of the acid hydrolases beta-glucuronidase and N-acetyl-beta-glucosaminidase. Cytochrome b was also found in smaller proportions in plasma membranes and specific granules. A significant proportion of the ubiquinone was located in the region of the gradients where specific granules and mitochondria sedimented. However, quantitative measurements of oligomycin-sensitive ATPase indicated that this second localization of ubiquinone could not be entirely attributed to mitochondrial contamination. Plasma membrane contained small amounts of ubiquinone. In addition, the existence and location of a putative proton pump ATPase were also investigated. The ATPase was mainly located in the plasma membrane and in the upper half of the gradients (tertiary and specific granules), with the highest specific activity occurring in the tertiary granules. This activity was inhibited by 100 microM DCCD. Furthermore, ATP-dependent uptake of [14C]methylamine by tertiary and specific granules was observed. These results suggest that the DCCD-sensitive ATPase may function as a proton pump. DCCD inhibited the release of enzymes from specific granules that occurred when human neutrophils were activated by phorbol myristate acetate. However, higher concentrations of DCCD were required to achieve the same degree of inhibition of O2 uptake (I50 of 0.4 mM for secretion versus 1 mM for O2 uptake). These results suggest that specific granules do not play a crucial role in oxygen metabolism.
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PMID:Subcellular localization of cytochrome b and ubiquinone in a tertiary granule of resting human neutrophils and evidence for a proton pump ATPase. 614 82