Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound   Target Concepts: 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)

A subclone of NG108-15 neuroblastoma-glioma hybrid cells was used to study the intracellular distribution of opioid receptors. Subcellular organelles were separated on self-generating Percoll-sucrose gradients and the enzymes beta-glucuronidase, galactosyltransferase, 5'-nucleotidase, and glucose-6-phosphatase were used as markers to localize the various structures. Analysis of the receptor distribution from untreated cells shows that the plasma membranes contained the highest receptor density, but a significant portion of the opioid binding sites was unevenly distributed between the lysosomes, microsomes, and Golgi elements. The enzyme markers indicated that appearance of opioid receptors in these intracellular structures does not result merely from contamination with plasma membranes. About 11% of the receptors appeared in a fraction lighter than plasma membranes. The antilysosomal agent chloroquine altered the intracellular compartmentation of the receptors, possibly by blocking their translocation in the cells. Leu-enkephalin induced time-dependent loss of receptors from all four intracellular compartments examined, but a kinetic analysis showed that the rate of receptor loss in these fractions was not identical. Thus, the percent of receptors appearing in the lysosomal fraction that could still bind [3H]D-Ala2-D-Leu5-enkephalin in vitro was increased on treatment with Leu-enkephalin. As an additional approach to follow the intracellular fate of the receptors, cells were labeled with [3H]diprenorphine, chased with various unlabeled opiates, and the distribution of 3H-ligand-receptors in the cells was monitored. Leu-enkephalin and etorphine altered the distribution of receptor-bound [3H]diprenorphine between the plasma membranes, lysosomes, and Golgi elements, whereas morphine had no such effect. The study sheds light on the role of intracellular structures in the metabolism of opioid receptors in untreated and opioid-treated cells.
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PMID:Subcellular compartmentation of opioid receptors: modulation by enkephalin and alkaloids. 300 5

The isolation of plasma membrane from human peripheral blood monocytes is described. Monocytes were isolated by centrifugal elutriation, to eliminate an adherence step, thus minimizing functional and surface antigenic alterations to the cells. Monocytes were surface-labelled with a radiolabelled monoclonal antibody, 125I-WVH-1, and then disrupted by nitrogen cavitation. Membranes were separated according to equilibrium buoyant density by isopycnic centrifugation on a sucrose gradient. The subcellular membranes were localized using marker enzymes for the plasma membrane, 5'-nucleotidase and leucine 2-naphthylamidase (leucine aminopeptidase), and for intracellular membranes: galactosyltransferase (Golgi), arylsulfatase C (endoplasmic reticulum), monoamine oxidase (mitochondria), catalase (peroxisomes), beta-hexosaminidase and beta-glucuronidase (lysosomal vesicles) and lactate dehydrogenase (cytosol). The monoclonal antibody 125I-WVH-1 was shown to label the plasma membrane, as judged by known markers, and represents a highly specific trace label, applicable to the use of plasma membrane as an immunogen for monoclonal antibody production. The NAD-splitting enzyme, NAD+ nucleosidase, was detected and its presence on the plasma membrane was demonstrated. The subcellular localization of non-specific esterase in human mononuclear phagocytes is controversial. No evidence was found for alpha-naphthyl acetate esterase activity on the plasma membrane or in lysosomal vesicles. However, a membrane-bound esterase in fractions with properties similar to the smooth endoplasmic reticulum was detected.
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PMID:Isolation of plasma membrane from human blood monocytes. Subcellular fractionation and marker distribution. 397 89

The series introduced by this paper reports the results of a detailed analysis of the microsomal fraction from rat liver by density gradient centrifugation. The biochemical methods used throughout this work for the determination of monoamine oxidase, NADH cytochrome c reductase, NADPH cytochrome c reductase, cytochrome oxidase, catalase, aminopyrine demethylase, cytochromes b(5) and P 450, glucuronyltransferase, galactosyltransferase, esterase, alkaline and acid phosphatases, 5'-nucleotidase, glucose 6-phosphatase, alkaline phosphodiesterase I, N-acetyl-beta-glucosaminidase, beta-glucuronidase, nucleoside diphosphatase, aldolase, fumarase, glutamine synthetase, protein, phospholipid, cholesterol, and RNA are described and justified when necessary.
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PMID:Analytical study of microsomes and isolated subcellular membranes from rat liver. I. Biochemical methods. 415 Apr 88

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

Subcellular fractions were prepared from mouse kidney homogenates by differential and sucrose-gradient centrifugation. A fraction enriched in Golgi apparatus was obtained, which had considerably enriched galactosyltransferase and thiamin pyrophosphatase activities, and was morphologically typical of Golgi material. This preparation also had high beta-glucuronidase activity, which increased concomitantly with microsomal beta-glucuronidase activity during the specific stimulation of the enzyme in male mouse kidney after androgen administration. The degree of stimulation was much greater in the Golgi fraction. Gel-electrophoretic patterns of Golgi beta-glucuronidase resembled more closely those of the enzyme located within lysosomes, but contained minor bands similar to those described previously (Swank & Paigen, 1973) as characteristic of the microsomal enzyme. It was concluded that the Golgi complex is involved in the distribution of the enzyme after its synthesis to both lysosomal and microsomal fractions.
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PMID:Golgi beta-glucuronidase of androgen-stimulated mouse kidney. 437 7

1. The following fractions were prepared from rat kidney and characterized ultrastructurally, biochemically and enzymically: (a) an ordinary rough microsomal (RM(1)) fraction; (b) a special rough microsomal (RM(2)) fraction enriched seven- to nine-fold in acid hydrolases over the homogenate; (c) a smooth microsomal (SM) fraction; (d) a Golgi (GM) fraction enriched 2.5-fold in acid hydrolases and 10-, 15- and 20-fold in sialyltransferase, N-acetyl-lactosamine synthetase and galactosyltransferase respectively; (e) a lysosomal (L) fraction enriched 15- to 23-fold in acid hydrolases. The frequency of Golgi sacs and tubules seen in the electron microscope and the specific activity of the three glycosyltransferases in these fractions increased in the order: RM(2)<RM(1)<SM<GM. 2. Five lysosomal hydrolases, acid phosphatase, beta-N-acetyl-hexosaminidase, beta-galactosidase, beta-glucuronidase and arylsulphatase, were characterized in these fractions with respect to (a) solubility on freeze-thawing and (b) electrophoretic mobility in polyacrylamide gels. 3. In the RM(2) fraction each of these hydrolases occurred largely or exclusively as a single bound basic form coincident with cationic glycoprotein bands in gels (Goldstone et al., 1973). 4. In the L fraction these hydrolases were present largely as soluble, acidic (anionic) forms. 5. The solubility, electrophoretic heterogeneity and anodic mobility of these hydrolases increased progressively in subcellular fractions in the order: RM(2)<RM(1)<SM<GM<L. 6. These findings, together with evidence cited in the text showing that N-acetylneuraminic acid residues are responsible for the solubility and electronegative charge of these acidic forms and incorporation of these residues into the Golgi apparatus, support the following scheme for the biosynthesis of lysosomal enzymes. Each hydrolase is synthesized as a bound basic glycoprotein enzyme in a restricted portion of the rough endoplasmic reticulum. The soluble, acidic forms are generated as the nascent glycoprotein enzymes migrate through the Golgi apparatus through the attachment of sugar sequences containing N-acetylneuraminic acid.
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PMID:Physicochemical modifications of lysosomal hydrolases during intracellular transport. 472 40

Dissociated sponge cell system has proved to be a useful model to study the process of cell aggregation both on cellular and subcellular level. The purpose of this review is to discuss recent results obtained from experiments with the marine sponge Geodia cydonium. Dissociated cells form functional aggregates during a process which can be sub-divided into three phases: first, formation of small primary aggregates in the presence of Ca2+; second, formation of secondary aggregates in the presence of an aggregation factor and third, reconstitution of a functional system of water-containing channels by rearrangement in the secondary aggregates. On subcellular level a series of macromolecules are known which are involved in the control of aggregation and separation of sponge cells: Aggregation factor, aggregation receptor, anti-aggregation receptor, beta-glucuronidase, beta-glucuronosyltransferase, beta-galactosyltransferase, beta-galactosidase and a lectin. These components might be linked in the following sequence: (a) Activation of the aggregation receptor by its enzymic glucuronylation; (b) Adhesive recognition of the cells, mediated by the aggregation factor and the glucuronylated aggregation receptor; (c) Inactivation of the aggregation receptor by its deglucuronylation with the membrane-associated beta-glucuronidase; (d) Cell separation due to either the loss of the recognition site (glucuronic acid) of the aggregation receptor for the aggregation factor or to an inactivation of the aggregation factor by the anti-aggregation receptor. The activity of the anti-aggregation receptor is most likely controlled by the Geodia lectin. The events leading to cell-cell recognition cause a change in the following metabolic events: Increase of oxygen uptake, decrease of cyclic AMP level, increase of cyclic GMP level and stimulation of programmed syntheses.
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PMID:Sponge cell aggregation. 624 12

Mouse peritoneal macrophages that had been treated with a monovalent carboxylic ionophore, monensin, selectively secreted lysosomal and nonlysosomal granular enzymes into the medium. When macrophages were incubated with 1 to 10 microM monensin, the release of beta-glucuronidase, beta-hexosaminidase and beta-galactosidase was stimulated time and does dependently. Neither the beta-glucosidase nor acid phosphatase, enzymes bound to the lysosomal membranes, however, were released by monensin. Neutral alpha-glucosidase, shown recently to be localized in nonlysosomal granules of macrophages (15), was released by monensin at concentrations lower than those required for lysosomal enzyme release. Increased release of lysosomal enzymes also took place in a manner similar to that seen with monensin-treated macrophages after treatment of macrophages with weak bases, chloroquine and ammonium chloride. Neutral alpha-glucosidase, however, was not released when chloroquine was present in concentrations that stimulated the release of lysosomal enzymes. The UDP-galactosyltransferase activity of the Golgi apparatus in the macrophages markedly decreased after treatment with low concentration of monensin.
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PMID:Stimulation of the release of lysosomal and nonlysosomal granular enzymes from macrophages treated with monensin. 643 21

To investigate the effect of ethanol or colchicine on the intracellular proteolytic processing of lysosomal beta-glucuronidase, which is considered to occur in the Golgi complex in the intracellular sorting pathway, three rat liver Golgi subfractions, GF-1, GF-2, and GF-3, were isolated from ethanol- or colchicine-treated rats, and the electrophoretic patterns of the extracted Golgi beta-glucuronidase on polyacrylamide gel were examined. The isolated Golgi subfractions from the drug-treated rats gave a better yield of fraction than that from the control rats. The enzymatic characterization of these three subfractions showed no significant contamination by other subcellular structures such as plasma membranes, microsomes, or lysosomes, and no inhibitory effect of the drugs was observed. On the other hand, suppressed galactosyltransferase activity, a marker enzyme of the Golgi complex, was detected in the colchicine-treated rats. The electrophoretic pattern of Golgi beta-glucuronidase on polyacrylamide gel revealed one major band which moved to the same position as the lysosomal enzyme type in the control rats. In contrast, in the ethanol- and colchicine-treated rats, Golgi beta-glucuronidase was found to have two major bands stained for enzyme activity resulting from a mixture of microsomal- and lysosomal-type enzymes. These results suggested that the post-translational modification step, during conversion from a microsomal-type enzyme to a lysosomal-type enzyme, was apparently inhibited. Taken together, these findings indicated that ethanol or colchicine administration to rats caused an inhibitory effect on the intracellular post-translational modification of Golgi beta-glucuronidase destined for targeting to the lysosomes.
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PMID:Inhibitory effect of ethanol and colchicine on the intracellular processing of beta-glucuronidase which occurs in the Golgi complex. 758 Dec 47


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