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:3.2.1.23 (beta-galactosidase)
14,648 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

It has been shown that low concentrations of E. coli lipopolysaccharides (LPS) greatly and selectively stimulate phagocytosis and related functions in mouse bone marrow-derived macrophages. Culture in the presence of 50 ng/ml LPS induced on average a 10-fold enhancement of phagocytosis of IgG-coated sheep erythrocytes. Activation was in two stages--a small increase observed during the first 8 to 12 hr, and the major increase noted between 16 and 24 hr. Phagocytic activity remained at the maximal level for 24 hr and then declined progressively. Stimulation by LPS was dose-dependent; significant effects could be observed at 0.8 ng/ml and the maximum was reached at 10 ng/ml. LPS-treated cells also showed a markedly increased tendency to form colonies. All these effects could be prevented by the addition of 100 ng/ml polymyxin B together with LPS, indicating that the active principle is lipid A. The LPS-dependent increase in phagocytic activity is probably mediated by increased Fc receptor capacity because both parameters were influenced in parallel by the stimulus. Phagocytosis-related events, such as enhanced hexose monophosphate shunt activity, H2O2 formation, and nitroblue tetrazolium reduction were also stimulated by LPS. By contrast, pinocytosis was unaffected. Measurements of cell-associated enzyme activities showed that lactate dehydrogenase, acid phosphatase, and cathepsin D were significantly increased. Beta-glucuronidase, beta-galactosidase, alkaline phosphodiesterase, and aminopeptidase were unchanged and NAD nucleosidase was markedly decreased after LPS treatment. 5'-Nucleotidase and glucosamine uptake were undetectable both in control and LPS-stimulated cells. LPS treatment induced a significant increase in cell-associated protein, but did not result in cell proliferation or increased cell loss as shown by the DNA content that remained constant. LPS-induced changes were dependent on de novo protein synthesis; cycloheximide prevented enhancement of phagocytosis, Fc receptor capacity, and colony formation.
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PMID:Stimulation of phagocytosis in bone marrow-derived mouse macrophages by bacterial lipopolysaccharide: correlation with biochemical and functional parameters. 673 51

The effect of diphenylhydantoin (DPH) on the release of lysosomal enzymes during resorption of cultured mouse calvarial bone was studied. The enzyme activities of beta-glucuronidase and beta-galactosidase in the culture medium was taken as indicators for lysosomal enzyme release. In concentrations 50 micrograms/ml or higher, DPH inhibited the release of beta-glucuronidase and beta-galactosidase in parallel with bone resorption as indicated by reduced release of 45Ca, Ca2+, Pi and hydroxyproline. The release of the cytosolic enzyme lactate dehydrogenase was not influenced by concentrations of DPH up to 50 micrograms/ml but higher concentrations caused an increased release indicating cell injury. When bone resorption was stimulated by prostaglandin E2, DPH (50 micrograms/ml) also reduced the mobilization of bone mineral and the release of beta-glucuronidase without influencing the release of lactate dehydrogenase. It is suggested that DPH by interfering with cellular release processes reduces the resorption of bone.
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PMID:Influence of diphenylhydantoin on lysosomal enzyme release during bone resorption in vitro. 677 82

The fibres used in this experiment were UICC asbestos fibres (chrysotile, amosite, crocidolite, either untreated or leached with oxalic acid), nemalite and glass fibres. Chrysotile was also treated with sulfur dioxide. Size distribution measurements by electron microscopic analysis, chemical analysis and measurement of specific surface area were performed. Haemolytic activity was studied in human red blood cells by kinetic analysis of the percentage of haemoglobin released; this generated information on the shape of the curve, the initial velocity of the haemolysis and the maximal haemolysis. The effect on rabbit alveolar macrophages was determined in vitro by the measurement of lactic dehydrogenase and beta-galactosidase released from alveolar macrophages cultured with the fibres. Amphiboles and chrysotile had opposite reactivities on red blood cells. Leaching did not change the shape of the curve with chrysotile whereas it modified that with amphiboles. The initial velocity decreased with leached chrysotile and increased with leached crocidolite or amosite. Maximal haemolysis was linearly dependent on the fibre concentration with amosite and crocidolite, but not with chrysotile or nemalite. The adsorption of sulfur dioxide onto chrysotile did not highly modify its haemolytic activity. In alveolar macrophages, chrysotile and leached amphiboles selectively released beta-galactosidase; and leached chrysotile and nemalite released both enzymes studied.
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PMID:Effects of well-defined fibres on red blood cells and alveolar macrophages. 678 90

Peritoneal exudate cells of mice were studied up to 4 days after i.p. injection of thioglycollate broth medium by means of conventional enzyme determinations and quantitative histochemical measurements of individual cells. Cells from the peritoneal cavity were either investigated immediately after harvesting or after culturing periods of up to six days for enzymic activities of aminopeptidase, esterase, lactate dehydrogenase and beta-galactosidase. A fairly good correlation exists between biochemical determinations of aminopeptidase and esterase activity and the mean of histochemical data. Following a sharp increase in the number of cells after stimulation, aminopeptidase, esterase and lactate dehydrogenase activities per cell were found to be increased. Moreover, the cells taken three or five days after simulation synthesized large amounts of aminopeptidase and esterase as shown by culturing experiments. This capacity of the cells was subsequently lost in cells harvested seven days after stimulation but beta-galactosidase increased and lactae dehydrogenase was more readily released into culture supernatants. The increase in aminopeptidase and esterase was dependent on protein synthesis since it was abolished by cycloheximide. Thioglycollate broth medium provokes immigration of cells into the peritoneal cavity where cells apparently differentiate by increasing their aminopeptidase and esterase concentrations, and by raising their intracellular catabolism rates, which leads eventually to the decay of the cells. The different enzymic phenotypes and the large heterogeneity at any time point after stimulation presumably also reflect different functional properties during the inflammatory process.
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PMID:Stimulated murine peritoneal macrophages in suspension and cell culture: enzyme determinations by biochemical and histochemical means. 680 41

Delta toxin, one of at least four toxins produced by pathogenic strains of the skin bacterium Staphylococcus aureus, is an amphipathic polypeptide possessing hemolytic and cytolytic activity. Delta toxin stimulates high levels of phospholipase A2 activity in 3T3 mouse fibroblasts with concomitant synthesis and release of prostaglandins. Alpha toxin, another hemolytic toxin produced by strains of S. aureus, did not stimulate phospholipase A2 or prostaglandin release in these cells. Analysis of the release of lactate dehydrogenase and beta-galactosidase (cytoplasmic and lysosomal marker enzymes, respectively) from delta-toxin-treated cells indicated that cytolytic concentrations of the toxin damage the cell-surface membrane more extensively than lysosomal membranes. During a 30 min exposure, delta toxin stimulated 3T3 cells to hydrolyze up to 32% of the lipids biosynthetically labeled by incorporation of [3H]arachidonic acid. A relatively high percentage of the free arachidonic acid formed in delta-toxin-treated 3T3 cells was converted to prostaglandins (up to 41.3% and 8.3% converted to chromatographically identifiable prostaglandins E2 and F2 alpha, respectively, in 30 min), with optimal conversion occurring at sublytic toxin concentrations. The degree of activation of phospholipase A2 in 3T3 cells by a range of concentrations of delta toxin correlates with cytotoxicity assessed by failure to exclude trypan blue dye. Analysis of the calcium dependency of the toxin-activated phospholipase A2 was consistent with a cell-surface, Ca2+-dependent enzyme. The phospholipase A2 exhibits a degree of specificity for substrate lipids containing polyunsaturated fatty acid residues which can serve as precursors for prostaglandin formation. Enzymatic activity was not inhibited by diisopropylfluorophosphate (5 mM), N-ethylmaleimide (5 mM) or p-bromophenacylbromide (0.1 mM). Delta toxin did not activate detectable phospholipase A2 in subcellular preparations containing plasma membrane.
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PMID:Staphylococcal delta toxin stimulates endogenous phospholipase A2 activity and prostaglandin synthesis in fibroblasts. 721 81

Biochemical studies of middle ear effusions have demonstrated generally higher levels of certain hydrolytic and oxidative enzymes in mucoid fluids when compared to serous. We have extended these studies by analyzing middle ear effusions for the content of a large number of lysosomal hydrolases. The mean specific activity for alpha-glucosidase in mucoid fluids was found to be ten times that for serous fluids while alpha-mannosidase, beta-glucuronidase, hexosaminidase, acid phosphatase, beta-galactosidase, alkaline phosphatase, and lactate dehydrogenase were found to be three to five times greater in mucoid than serous effusions. In this study the specific enzyme activities for lysosomal hydrolases from purulent effusions were found to be intermediate between the activities in serous and mucoid effusions. No significant correlation was found between the specific activities of lysosomal hydrolases and the presence or absence of bacteria in mucoid or serous middle ear effusions. The hexosaminidase isozyme distribution was found to be identical for serous and mucoid fluids and similar to that found in human serum. However, the isozyme pattern of beta-glucuronidase in mucoid effusions was significantly different than that in normal human serum as mucoid fluids contain a large amount of an anionic isoenzyme of beta-glucuronidase that is barely detectable in human serum.
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PMID:Lysosomal hydrolases in middle ear effusions. 722 13

The effect of indomethacin on bone resorption was studied in an organ culture system, using calvarial bones from 6--7-day-old mice. It was found that indomethacin inhibited spontaneous bone resorption, as estimated by decreased release of 45Ca, Ca2+ and Pi. Indomethacin reduced the release of beta-glucuronidase, beta-galactosidase and beta-N-acetylglucosaminidase, diminished glucose consumption and lactate production, but showed no effect on the release of lactate dehydrogenase. No inhibitory effect of indomethacin on the release of 45Ca stimulated by parathyroid hormone, prostaglandin E2 or 1 alpha(OH)D3 could be registered. 5,8,11,14-eicosatetraynoic acid, an inhibitor of both cyclo- and lipoxygenase pathway of arachidonate metabolism, reduced the spontaneous release of 45Ca, whereas the selective lipoxygenase inhibitor 5,8,11-eicosatriynoic acid was without effect. The results presented indicate that indomethacin may have an inhibitory effect upon the osteoclasts, probably by decreased metabolism of arachidonic acid via the cyclo-oxygenase pathway. A possible relationship between this finding and the pathogenesis of rapid destruction of articular bone in osteoarthritic patients treated with indomethacin is discussed.
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PMID:Indomethacin inhibits bone resorption and lysosomal enzyme release from bone in organ culture. 745 22

Components of the mammalian sperm acrosome that have been conserved during evolution are probably essential for fertilization and are therefore potential antigens for the development of an immunocontraceptive vaccine. In order to identify such protein components, a series of specific polyclonal antisera were generated by immunizing rabbits with purified acrosomal membrane fractions from hamster epididymal spermatozoa. Antisera were finally selected using immunological and in-vitro fertilization assays, and used to then screen a human testis lambda gt11 cDNA library. As a result of this screening over 70 clones were identified, selected and purified. The cDNAs were amplified by polymerase chain reaction (PCR) and the inserts characterized by restriction enzyme digestion and oligonucleotide probing techniques. The functional activity beta-galactosidase fusion proteins expressed by these clones (HA5-2, HA6-2 and HB4-1) inhibited significantly fertilization and reduced spermatozoa binding compared to controls. To date, sequence data has been obtained from HB4-1 (1.75 kb). The first 1132 nucleotides displayed > 96% homology to human testis-specific lactate dehydrogenase (LDH-C4) gene, the product of which is a known candidate antigen for a contraceptive vaccine. This finding suggests that a strategy involving the screening across species for conserved moieties of the mammalian acrosome may be useful for identifying candidate antigens for immunocontraception.
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PMID:A strategy for identifying candidate sperm antigens for immunocontraception: isolation of human testis cDNA clones using polyclonal antisera directed against hamster acrosomal membrane preparation. 755 86

The stabilizing effect of mannitol during the freeze-drying of proteins was studied using L-lactate dehydrogenase (LDH, rabbit muscle), beta-galactosidase (Escherichia coli) and L-asparaginase (Erwinia chrysanthemi) as model proteins. Crystallization of mannitol was studied by powder X-ray diffraction and differential scanning calorimetry (DSC), in relation to the stabilizing effect. All the enzymes were protected concentration-dependently by amorphous mannitol, but the stabilizing effect was decreased with an increase in mannitol crystallinity. The heat-treatment of frozen solutions above crystallization temperature prior to drying enhanced mannitol crystallization and LDH inactivation. The importance of maintaining excipients in an amorphous state during freeze-drying, previously reported for Aspergillus oryzae beta-galactosidase (K. Izutsu et al., Pharm. Res., 10, 1233 (1993)), was confirmed using three different enzymes.
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PMID:Effect of mannitol crystallinity on the stabilization of enzymes during freeze-drying. 812 65

Advances in liver surgery and transplantation have lead to a steady increase in the number of these interventions. Prompt quantitative assessment of hepatic of hepatic function and a patient's subsequent morbidity and mortality following surgery remain difficult despite the currently utilized historic markers of hepatic parenchymal injury (e.g., aspartate transaminase [AST], lactate dehydrogenase [LDH] gamma-glutamyl transpeptidase [GGT]). Increases in serum glycohydrolase activities appear to provide sensitive and quantitative markers of hepatic ischemia/reperfusion injury. In 10 male swine (25 to 35 kg body weight) following 30, 45, and 90 minutes of acute hepatic ischemia, the systemic release of eight different glycohydrolases and lipid peroxides into serum were determined and compared with pre- and postischemic serum levels of LDH, GGT, and AST. The rapid release of glycohydrolases into serum was directly proportional to the length of the ischemic period from 30 to 90 minutes; e.g., beta-glucosidase, mean 1.9-fold increase at 30 minutes; 8.3-fold at 45 minutes; and 22.8-fold at 90 minutes; P < .002) and the activities peaked within the first 3 hours postischemia. In constrast, AST, LDH, and GGT were released slowly and peaked 20 to 30 hours after hepatic blood flow was restored. In swine with fatal outcomes (90 minutes of ischemia), all enzyme levels increased continuously during the final hours of life. However, in swine that survived hepatic ischemia/reperfusion injury (45 minutes of ischemia) the glycohydrolases, but not AST, LDH, and GGT, declined after 2 to 3 hours' postischemia and the serum lipid peroxide levels followed the same pattern. Serum beta-galactosidase and beta-glucosidase levels are sensitive markers that rise as quickly as traditional enzyme markers (AST, LDH, GGT) following hepatic ischemic injury; moreover, the glycohydrolases have the added value of serving as predictors of survival.
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PMID:Glycohydrolases as markers of hepatic ischemia-reperfusion injury and recovery. 870 56


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