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)

The development of experimental cholecystitis produced by lysophosphatidylcholine is associated with reversal of the normal absorptive characteristics of gallbladder mucosa, resulting in the intraluminal accumulation of water, glycoprotein, and protein. The purpose of the present study was to attempt to ascertain if the protein leaks into the lumen because of the cytolytic properties of lysophosphatidylcholine or if it is due to an active secretory process and to characterize the protein produced. Experiments were performed on anesthetized cats undergoing gallbladder perfusion with and without lysophosphatidylcholine. The amount of protein in the perfusate was measured and albumin clearance from blood to gallbladder lumen was calculated with and without the administration of vesicular transport inhibitors. In separate experiments, control and lysophosphatidylcholine (LPC) produced gallbladder perfusates were collected and the protein subjected to SDS-PAGE to ascertain the nature of the protein secreted. Inhibitors of both microtubular and microfilament activity decreased the protein accumulation and clearance produced by lysophosphatidylcholine. Gallbladder white blood cell accumulation and inflammation as evaluated by beta-glucuronidase and prostaglandin E levels were not significantly altered by cytochalasin or colchicine administration. Lysophosphatidylcholine also produced significant increases in perfusate LDH levels. The protein produced was primarily a 66-kDa protein. Transfer of the protein to a nitrocellulose membrane and immunoblotting with anti-albumin antibody demonstrated that the protein was albumin. The results suggest that during the development of cholecystitis, lysophosphatidylcholine produces albumin accumulation in the gallbladder primarily by inducing an active secretory process resulting in gallbladder distension.
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PMID:Gallbladder mucosal protein secretion during development of experimental cholecystitis. 772 80

Factor J (FJ) is a new inhibitor of the complement system. This work supports the fact that FJ is a cationic molecule (pI > or = 9.6 in native conditions, or pI = 8.1 in denaturing conditions) with a high sugar content (40%) that is able to interact with different lectins, suggesting a complex glycosylation. SDS impaired FJ migration in polyacrylamide gel electrophoresis. In Triton-acid-urea-polyacrylamide gel electrophoresis FJ migrated as a complex, dispersed molecule. In contrast, FJ after Smith degradation (dFJ) gave a single, smeared band of M(r) = 23.4 kDa in reducing SDS-PAGE. dFJ retained only 60% of the initial inhibitory activity of intact FJ. When digestions with different proteinases were performed, no modification of activity was observed. After beta-glucuronidase digestion, FJ lost 80% of its initial activity. Consequently, glycosylation plays an important role in the inhibitory activity of FJ.
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PMID:Factor J, a human inhibitor of complement C1, is a cationic, highly glycosylated protein. 789 Mar 18

The neutrophil plasma membrane has a major role in migration, phagocytosis, and destruction of microorganisms. Neutrophils isolated from blood and mammary secretions were homogenized, and the plasma membrane fraction was isolated on discontinuous sucrose gradient (20, 32, and 50%). Purity of plasma membrane preparation was determined by use of marker enzyme analysis. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) of the membrane proteins was performed under reducing conditions for polypeptide characterization. The membrane proteins were also labeled with 125I externally, using 1,3,4,6-tetrachloro-3 alpha-6 alpha-diphenylglycouril, and proteins were separated by SDS-PAGE and autoradiographed. Compared with whole cell homogenate, the plasma membrane fraction obtained at the 20/32% interface was enriched for the marker enzymes, 5'-nucleotidase (16-fold), alkaline phosphatase (5.5-fold), and total phosphatase (26-fold). The membrane fraction had minimal specific activity for beta-glucuronidase (0.4-fold), compared with whole cell homogenate. Plasma membrane protein yield was about 500 micrograms/10(9) bovine blood neutrophils. The SDS-PAGE of plasma membrane proteins revealed 25 protein bands, of which 13 were major bands. There were 3 distinct bands (18, 36, and 65 kd) in the plasma membrane-enriched fraction (20/32 interface) that were not seen in other fractions (30/50% and pellet). Further, 125I-labeling identified 5 distinct protein bands (205, 140, 65, 35, and 30 kd). Blood and mammary neutrophils had similar polypeptide patterns, except that 36- and 65-kd bands were more prominent for blood neutrophils than for mammary neutrophils.
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PMID:Isolation and partial polypeptide characterization of bovine neutrophil plasma membranes. 794 18

Bull seminal plasma contains high levels of beta-glucuronidase. The present study describes the isolation and characterization of beta-glucuronidase, and its role in fertilization. beta-glucuronidase was purified by ion exchange chromatography, saccharolactone-agarose affinity chromatography, and gel filtration. The specific activity of the purified enzyme was 4,414 mumoles/mg protein/min. The purified enzyme showed a single band on 7.5% PAGE. On SDS-PAGE, the enzyme appeared to consist of four identical subunits of M(r) 75,000 each. The apparent Km and Vmax for beta-glucuronidase were 0.4 mM and 5.7 mumol/min using phenolpthalein mono-beta-glucuronic acid as the substrate. beta-glucuronidase appeared to accelerate the cumulus dispersion in vitro.
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PMID:Purification and characterization of beta-glucuronidase from bull seminal plasma and its role in fertilization. 798 Sep 49

The nucleotide (nt) sequence of a 2.57-kb Sau3A fragment carrying the Rhizobium meliloti beta-galactosidase (beta Gal)-encoding gene (RmlacZ) was determined. An open reading frame (ORF) of 2.26 kb was identified which encoded a 755-amino-acid (aa) polypeptide with a calculated molecular mass of 84,141 Da, in fair agreement with the value of 88 kDa determined by SDS-PAGE. The deduced N-terminal aa sequence was confirmed by direct sequencing of electrophoretically purified R. meliloti beta Gal. The size of the native R. meliloti beta Gal was approx. 174 kDa. Similarities were found between the aa sequence of the R. meliloti beta Gal and those from Clostridium thermosulfurogenes EM1 and Agrobacterium radiobacter, as well as human beta-glucuronidase (beta Glu). Comparisons with beta Gal from Escherichia coli, Klebsiella pneumoniae, Lactobacillus bulgaricus and Kluyveromyces lactis found only weak similarities; however, the putative active site residues appear to be conserved. The RmlacZ sequence is flanked by two partially sequenced ORFs, which show aa sequence and organisational similarities to the previously reported lac operon in A. radiobacter.
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PMID:Nucleotide and deduced amino acid sequences of Rhizobium meliloti 102F34 lacZ gene: comparison with prokaryotic beta-galactosidases and human beta-glucuronidase. 816 82

Organophosphate compounds are known to cause the selective release of rat liver microsomal beta-glucuronidase into plasma. To investigate the alterations of molecular forms and oligosaccharide moieties of liver beta-glucuronidase in organophosphate compound-administered rats, beta-glucuronidase was isolated from microsomal, Golgi, lysosomal, and serum fractions. In SDS-polyacrylamide gel electrophoresis, a single polypeptide band was observed on gels in Golgi and serum beta-glucuronidases. This result indicated that Golgi and serum beta-glucuronidases of treated rats did not undergo post-translational proteolytic processing, in contrast to those in control rat livers. Biochemical characterization of the isolated beta-glucuronidases by employing lectin affinity chromatography revealed that interaction of serum and Golgi enzymes with Ricinus communis agglutinin- and wheat germ agglutinin-Sepharose was fairly strong, and that microsomal and lysosomal enzymes were poorly retained on those columns. These results suggested that the serum and Golgi beta-glucuronidases are sialoglycoproteins. A clearance study also showed that infused serum beta-glucuronidase was slowly cleared from plasma with a half-life of about 60 min, but the asialo-serum enzyme was rapidly cleared with a half-life of about 5 min. These results imply that microsomal beta-glucuronidase undergoes extensive modification of the oligosaccharide moieties by terminal glycosyltransferases at the trans Golgi when it is destined for secretion into serum in response to treatment with an organophosphate compound.
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PMID:Biochemical characterization of liver microsomal, Golgi, lysosomal, and serum beta-glucuronidases in dibutyl phosphate-treated rats. 853 26

When cDNAs for human and rodent beta-glucuronidases were expressed in COS-7 cells using several different promoters, rodent beta-glucuronidases were produced three times more than human beta-glucuronidase, although their transcriptional levels were similar. Similar observations were also recorded in LMTK- cells using SV40 early or chicken beta-actin promoters. In hopes of enhancing yields of recombinant human beta-glucuronidase for enzyme replacement therapy, we sought to determine the region within the linear sequences responsible for the higher levels of expression of the rodent cDNAs. To do so, we made various rat-human chimeric cDNAs utilizing conserved restriction enzyme sites. The levels of products expressed from these chimeric cDNAs in COS cells were assessed by activity assay and by metabolic labeling of the proteins followed by immunoprecipitation and SDS-PAGE. From the results of these expression studies, we identified a 155-bp ClaI (643)-AflII (797) fragment in the rat open reading frame responsible for the increased rate of translation of the rat beta-glucuronidase (RBG) cDNA. Replacement of the homologous ClaI (683)-AflII (838) fragment in human beta-glucuronidase (HBG) with this 155-bp fragment from RBG increased the translation level of the resulting chimeric HRaH. Conversely, substitution of the 155-bp human fragment for that of rat in RBG cDNA reduced the total synthesis of the resulting chimeric HHaR. Placement of the 155-bp segment between the initiation ATG and the promoter has only negative effects on the expression of either cDNA. A more stable secondary structure of the human cDNA in this region might explain a reduced rate of translation. However, secondary structure analysis of mRNAs from the 155-bp fragment of rat and human cDNAs predicted that, while both can form stem-loops, the rat fragment (delta Gzero = -42.1 kcal/ mol) is actually more stable than the human fragment (delta Gzero = -32.1 kcal/mol). In fact, the free energy of stability of the first 50 bp within this ClaI-AflII fragment from rat (-10.3 kcal/mol) indicates that the secondary structure is considerably more stable than the corresponding 50 bp from human (-2.1 kcal/mol). This segment of the rat sequence also contains a tar-like sequence in a stem-loop. Although tar-like sequences can enhance rates of translation, altering this sequence by mutagenesis had no effect on the rate of synthesis of rat beta-glucuronidase. Thus, although the region conferring enhanced rate of synthesis from rat cDNA has been identified, the mechanism by which it does so is not yet clear.
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PMID:Enhanced translation of rat beta-glucuronidase cDNA is conferred by 155-bp segment of internal coding sequence. 880 77

As4.1, a renin-expressing cell line isolated from a mouse renal tumor, was characterized for synthesis, processing, storage and secretion of renin polypeptides. Metabolic labeling, immunoprecipitation and SDS/PAGE analysis revealed that renin was secreted into the culture supernatant predominantly in the form of prorenin which migrated as products of 42-47 kDa. The predominant intracellular renin was processed into two chains, of 33-34 and 5 kDa. N-glycanase treatment removed N-linked oligosaccharides and yielded products of 41 kDa for prorenin and 31-32 kDa for the heavier chain of two-chain renin. The N-terminus of the constitutively secreted prorenin was determined by automated Edman degradation to be Leu22 while the N-terminus of the heavy chain was Ser72. Renin polypeptides constituted 3.1 +/- 1.4% (mean percentage of total precipitable radioactivity +/- SD) of de-novo-synthesized protein secreted into the medium and 0.2 +/- 0.17% retained intracellularly. Extrapolation of renin activity assays suggest that a single cell stores approximately 680 fg of active renin. A slow incremental release into the medium of processed renin heavy chain was detected by immunoprecipitation and SDS/PAGE. Renin activity assays confirmed the release of approximately 4 fg prorenin and 0.32 fg active renin cell(-1) h(-1). Indirect immunofluorescence demonstrated intracellular renin to be distributed in a punctate pattern. Renin was found to be colocalized with the lysosomal marker, beta-glucuronidase, by double-fluorescent labeling. These cells have enabled characterization of glycosylated mouse renin-1 and may prove a valuable tool for studying intracellular trafficing of renin and associated processing enzymes.
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PMID:Biosynthesis of renin in mouse kidney tumor As4.1 cells. 903 Jul 38

The gelatinolytic activity in tracheal aspirates (TA) of horses with chronic obstructive pulmonary disease (COPD) was analyzed using SDS-PAGE-gelatin-gel electrophoresis (zymography) and compared to TAs from healthy controls. The 110-90 kD MMP-9 type gelatinase was high in symptomatic disease phases (permanent disease 0.46 +/- 0.15, p < 0.001; or intermittent disease 0.47 +/- 0.12, p < 0.001) compared to healthy controls (0.10 +/- 0.07). Similarly, the overall gelatinolytic activity, the activity in high-mw gelatinolytic bands (210-190 and 150 kD) and in proteolytically processed fragments in the 50-40 kD range were high, whereas the 75-65 kD MMP-2 was not altered. These findings suggest that MMP-9 type gelatinases, originating possibly from neutrophils or macrophages, and products thereof have a role in the pathogenesis of equine respiratory diseases, whereas MMP-2 type gelatinases represent house-keeping proteinases involved with normal tissue remodelling. The gelatinolytic activity in TAs correlated with the beta-glucuronidase activity, which indicates that they are simultaneously elevated in the respiratory secretions of horses suffering from COPD and might both be of same origin, or have a causal relationship.
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PMID:Gelatinolytic activity in tracheal aspirates of horses with chronic obstructive pulmonary disease. 912 43

A new binding protein, which recognizes a specific peptide sequence from pronase digested bovine beta-glucuronidase, has been isolated from bovine liver membranes. Prior work has shown that this peptide (IIIb2) contains a Ser-X-Ser sequence, where X might be a posttranslational modified Trp. This receptor was detergent-extracted from total bovine liver membranes and purified by affinity chromatography on a bovine beta-glucuronidase-Sepharose and a IIIb2 peptide-Sepharose column. Binding of bovine beta-glucuronidase to the isolated receptor requires divalent cations, and their presence was necessary to maintain the receptor-ligand complex. Only the peptide sequence containing the fraction IIIb2 was able to impair the binding of the bovine enzyme to the receptor, no other peptide from bovine beta-glucuronidase had an effect on binding. When analyzed by SDS-PAGE under reducing conditions, two bands were observed, a major band of 78 kDa and a faint band of 72 kDa. Rabbit antibodies against this binding protein revealed the presence of the 78 kDa protein in membranes from bovine liver, human and bovine fibroblasts. These antibodies impaired human fibroblasts endocytosis of the bovine but not of the human beta-glucuronidase, which is taken up by a 300 kDa receptor that recognizes phosphomannosyl moieties in the enzyme.
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PMID:Mannose 6-phosphate-independent endocytosis of beta-glucuronidase. II. Purification of a cation-dependent receptor from bovine liver. 1133 86


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