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

---

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

Trehalose diesters (natural 6,6'-trehalose dimycolate from Mycobacterium tuberculosis or synthetic (a 76 carbon atom analogue)), when suspended in water, give stable and well-defined emulsions. These emulsions, injected i.p. in mice significantly limit the growth of P815 syngeneic mastocytoma cells. They elicit macrophages with a cytostatic activity against P815 cells in vitro, strong enough to be expressed at low effector to target ratios (E/T = 1.4) or after a short coincubation period (2 hr). The antitumor potential of these macrophages seems to coincide with their ability to release H2O2 upon pharmacologic triggering. Depressed levels of alkaline phosphodiesterase and beta-galactosidase are proposed as other biochemical markers of cytostatic macrophages.
...
PMID:Antitumor activity and hydrogen peroxide release by macrophages elicited by trehalose diesters. 680 86

Polymorphonuclear leucocytes were isolated from pig blood relatively free from other cells and were characterised biochemically and morphologically and compared with human PMNLs. The activities of 16 enzymes of porcine and human PMNLs were measured and compared. Alkaline phosphatase, acid phosphatase, phosphodiesterase, gamma-glutamyl transpeptidase, NADH-cytochrome c oxidoreductase, malate dehydrogenase and acetylcholinesterase had higher specific activities in procine than in human cells. Alkaline phosphatase has an 87-fold higher specific activity in porcine than in human cells. beta-glucuronidase, lysozyme, beta-galactosidase, N-acetyl-glucosaminidase, beta-glucosidase, myeloperoxidase and catalase had higher specific activities in human than in porcine cells. beta-glucuronidase and myeloperoxidase showed over a 1000- and a 13-fold higher specific activity, respectively, in human than in porcine cells. Porcine PMNLs are readily available in large numbers and are recommended for studies of phagocytosis, chemotaxis and membrane biochemistry.
...
PMID:Biochemical characterisation of porcine polymorphonuclear leucocytes: comparison with human polymorphonuclear leucocytes. 687 22

Activities of lysosomal hydrolases were measured in the leucocytes of cattle, sheep, goats, horses and pigs. There was high activity of arylsulphatase in leucocytes from cattle, high activities of alpha-fucosidase and beta-glucuronidase in leucocytes from horses and high activity of acid phosphatase in granulocytes from pigs. Within species, arylsulphatase and beta-galactosidase activities were higher in granulocytes than in mononuclear cells, but beta-glucuronidase, phosphodiesterase and alpha-galactosidase activities were higher in mononuclear cells than in granulocytes. Eosinophils of cattle, sheep, goats and horses contained at least 10 times the activity of alpha-mannosidase and arylsulphatase found in neutrophils. For most of the other enzymes studied, there were differences in cattle and goats but not in sheep, horses or pigs between their specific activities in neutrophils and eosinophils.
...
PMID:Lysosomal hydrolase activity in leucocytes from cattle, sheep, goats, horses and pigs. 715 6

The purpose of the present study was to determine the role of cardiac lysosomal enzymes in the pathogenesis of the cardiomyopathy that develops in the genetically diabetic C57BL/KsJ db+/db+ mice. Db+/db+ mice and littermate controls were sacrificed as age-matched pairs between 5 and 26 weeks of age. C57BL/6J ob/ob mice and littermates served as other controls. Following anesthesia, the hearts were excised, homogenized, and the following enzymatic activities measured: N-acetyl-beta-glucosaminidase, N-acetyl-beta-galactosaminidase, beta-glucosaminidase, aryl sulfatase, alpha-mannosidase, alpha-glucosidase, beta-galactosidase, beta-glucosidase, total rho-nitrophenyl phosphatase, acid phosphatase. and 5'-phosphodiesterase type IV. There is a progressive decrease in cardiac lysosomal enzyme activities of db+/db+ mice for the period 5 to 21 weeks of age. All enzyme activity is depressed significantly during the 9- to 21-week interval: alpha-glucosidase, beta-glucosidase, alpha-mannosidase, beta-galactosidase, acid phosphatase, N-acetyl-beta-galactosaminidase, 5'-phosphodiesterase type IV, and total rho-nitrophenyl phosphatase are reduced approximately 10 to 20 per cent, whereas beta-glucosaminidase, aryl sulfatase, and N-acetyl-beta-glucosaminidase are decreased almost 40 to 50 per cent. In contrast, cardiac lysosomal enzymic activity in the ob/ob mice does not differ significantly from controls aside from aryl sulfatase (20 per cent decrease) and beta-glucosidase (10 per cent decrease). This decrease in lysosomal enzyme activity can explain the accumulation of large residual bodies and interstitial material that occurs in the myocardium of the db+/db+ animals as part of the cardiomyopathy.
...
PMID:Lysosomal enzymes in the heart of the genetically diabetic mouse. 742 Nov 26

The corticotropin releasing factor (CRF) receptor is known to be coupled to Gs and transduces its signal through stimulation of cyclic AMP (cAMP) production. Here we describe the characterization of several stable CRF receptor-expressing LVIP2.0Zc cell lines that also contain an exogenous cAMP-responsive beta-galactosidase reporter gene construct. The CRF receptor activity was assayed by measuring the induction of beta-galactosidase in response to CRF. Rat/human and bovine CRF stimulated beta-galactosidase activity in a dose-dependent manner with EC50 values of approximately 0.1 nM; the biologically weak deamidated analog of bovine CRF was approximately 500-fold less potent. The CRF receptor antagonist, [d-Phe12,Nle21,38,Ala32]r/hCRF(12-41) produced a dose-dependent inhibition of CRF-stimulated beta-galactosidase activity, further demonstrating the pharmacological specificity of the interaction. The magnitude of the maximal response to CRF varied among individual cell lines. This variation was independent of the level of CRF receptor expression, but reflected differences in the intrinsic activity of adenylate cyclase. In contrast to most cAMP assay systems, the phosphodiesterase inhibitor 3-isobutyl-1-methylxanthine decreased the CRF-induced beta-galactosidase activity when used in the context of the assay regimen described here. Since the assay can be easily performed in a high-throughput 96-well plate format, these cell lines provide an efficient way for the identification of CRF receptor agonists and antagonists.
...
PMID:Colorimetric assay for rapid screening of corticotropin releasing factor receptor ligands. 753 19

cAMP acts as a primary signal and is regulated by a secreted cyclic nucleotide phosphodiesterase (PDE) throughout development in Dictyostelium discoideum. Expression of the PDE gene (pde) is controlled by promoters specific to vegetative growth (prV), aggregation (prA), or late development (prL). Promoter-containing regions were individually fused to the pde coding sequence. After transformation multiple copies of each construct led to overexpression of PDE mRNA and enzyme activity with the temporal profile expected of each promoter. Overexpression of PDE from prV and prA altered the timing of aggregation compared to control transformants, but the final morphology was normal. Control transformants showed delayed aggregation compared to nontransformed cells. Cells that overexpressed PDE from prL aggregated like the control transformants, but no fruiting bodies were formed. Individual promoter regions were fused to the beta-galactosidase gene (lacZ). Cells that expressed prA-lacZ were dispersed throughout aggregation fields and mounds. Cells that expressed prL-lacZ were first seen distributed homogeneously throughout tight and tipped mounds. In slugs most of these cells are localized in the anterior region. During culmination, cells that expressed the prL-lacZ construct became incorporated into the stalk and were seen in the upper and lower cups surrounding the spore mass.
...
PMID:The role of the cyclic nucleotide phosphodiesterase of Dictyostelium discoideum during growth, aggregation, and morphogenesis: overexpression and localization studies with the separate promoters of the pde. 838 36

Actinomyces viscosus T14V, a Gram-positive bacterium found in the oral cavity, was found to be insensitive to glucose-mediated catabolite repression. Basal levels of beta-galactosidase (18-26 U) were observed at all phases of growth regardless of the culture conditions. Further, beta-galactosidase could not be induced with lactose, or with a known inducer of the enzyme, isopropyl-beta-D-thiogalactoside, or with dibutyryl cAMP. Glucose, on the other hand, stimulated cAMP accumulation in a concentration-dependent manner. Fructose and sucrose mimicked the effects of glucose on cAMP accumulation, whereas galactose, mannose and maltose had lesser stimulatory effects. Other carbon sources, i.e., lactose, alpha-methylglucoside, ribose, xylose and succinate were without effect. Glucose and alpha-methylglucoside were found to stimulate cAMP accumulation in toluene-permeabilized cells, in the presence of the phosphodiesterase inhibitor, theophylline. Glucose did not stimulate cAMP levels in other Gram-positive bacteria including Streptococcus mutans, S. sanguis and S. salivarius but did cause cAMP accumulation in other strains of A. viscosus. The results suggest that glucose effects on cAMP metabolism are independent of the induction of beta-galactosidase as presently defined for Escherichia coli, and that the effects appear to be selective to the A. viscosus bacteria. The results also suggest that glucose stimulates cAMP accumulation via activation of adenylate cyclase.
...
PMID:Glucose stimulates cAMP accumulation in the oral bacterium Actinomyces viscosus. 839 89

It was demonstrated previously that a deoxyribophosphodiesterase (dRpase) activity is associated with the DNA repair enzyme exonuclease I, and that this activity is stimulated by the addition of the E. coli single-stranded DNA-binding protein (Ssb). This activity catalyzes the release of deoxyribose-phosphate groups at apurinic/apyrimidinic (AP) sites in the DNA that have been cleared by the action of an AP endonuclease. We have now used the yeast two-hybrid system to demonstrate that a protein-protein interaction occurs between exonuclease I and Ssb. When the E. coli ssb gene was fused in frame to the DNA-activating domain of the GAL4 transcriptional activator and the exonuclease I gene was fused in frame to the DNA-binding domain, a functional GAL4 transcriptional activator was produced as determined by growth of yeast on selective medium and the measurement of beta-galactosidase activity. We have also demonstrated that Ssb can stimulate the dRpase activity of exonuclease I using double-stranded bacteriophage M13 DNA containing several strand interruptions at incised AP sites. These results suggest that Ssb may be required for efficient base-excision repair in bacteria.
...
PMID:Protein-protein interactions between the Escherichia coli single-stranded DNA-binding protein and exonuclease I. 861 28

We have identified a gene, cpdA, located at 66.2 min of the chromosome of Escherichia coli that encodes cyclic 3',5'-adenosine monophosphate phosphodiesterase (cAMP phosphodiesterase, EC). The expression of beta-galactosidase, which is a product of the lacZ gene, was repressed in cells that harbored multiple copies of the plasmid carrying the cpdA gene. Northern blotting showed that the transcription of the lacZ gene was inhibited in these cells. Multiple copies of the cpdA gene decreased the intracellular concentration of cAMP, which is a positive regulator for transcription of the lacZ gene. We found that the purified CpdA protein repressed in vitro transcription from the lacP1 promoter by decreasing cAMP. In addition, we showed that the CpdA protein hydrolyzed cAMP to 5'-adenosine monophosphate and that its activity was activated by iron. Our results suggested that regulation of intracellular concentration of cAMP is dependent not only on synthesis of cAMP but also on hydrolysis of cAMP by cAMP phosphodiesterase.
...
PMID:Identification of the cpdA gene encoding cyclic 3',5'-adenosine monophosphate phosphodiesterase in Escherichia coli. 881 Mar 11

Proliferating, activated, hepatic stellate cells have a high level of collagen type I expression. Therefore, stellate cell proliferation is a critical step in hepatic fibrosis. Here we show that proliferation of activated primary rat stellate cells was blocked by elevation of cAMP with 8 Br-cAMP or isomethylbutyl xanthine, a phosphodiesterase inhibitor, and by stimulation of Ca2+ fluxes with the Ca2+ ionophore A-23187. Because phosphorylation of CREB on Ser133 is an important mediator of cAMP-protein kinase (PKA) and Ca2+-calmodulin kinase II (CAMK-II) activation, we tested whether CREB-PSer133 was essential for stellate cell quiescence. Nuclear extracts from quiescent, but not from activated, stellate cells contained CREB-PSer133. Moreover, the phosphorylation of CREB on Ser133 was stimulated in activated cells by inducing the activity of PKA or CAMK-II. In addition, coexpression of CREB and either a constitutively active PKA or a constitutively active CAMK-II inhibited the proliferation of activated stellate cells. In contrast, expression of CREB alone, PKA or CAMK-II alone, CREB-Ala 133 (which lacks the Ser133 phosphoacceptor) with PKA or CAMK-II, or CREB with inactive PKA or CAMK-II mutants did not affect stellate cell proliferation, suggesting that CREB-PSer133 is necessary for blocking the stellate cell cycle. Conversely, expression of a trans-dominant negative CREB-Ala 133 mutant (which competes with CREB/CREB-PSer133 for cognate DNA binding sites and presumably for protein interactions) induced a greater than fivefold entry into S-phase of quiescent stellate cells, compared with control cells expressing either beta-galactosidase or wt CREB, indicating that CREB-PSer133 may be indispensable for the quiescent stellate cell phenotype. This study suggests that PKA and CAMK-II play an essential role on stellate cell activation through the induction of CREB phosphorylation on Ser133, and provides potential approaches for the treatment of hepatic fibrogenesis in patients with chronic liver diseases.
...
PMID:Proliferation of hepatic stellate cells is inhibited by phosphorylation of CREB on serine 133. 907 42


<< Previous 1 2 3 4 5 Next >>

---