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)

5-Aminolevulinic acid (ALA) is a heme precursor that accumulates in some porphyric disorders and in lead poisoning which can undergo metal-catalyzed oxidation producing reactive oxygen species and the keto-aldehyde, 4,5-dioxovaleric acid (DOVA). Evidence in vitro of ALA-induced DNA lesions suggests that ALA and DOVA have mutagenic potential that could possibly contribute to an increased frequency of hepatocellular carcinoma (HCC) in patients with acute intermittent porphyria (AIP). In this study, we evaluated the genotoxic potential of ALA and DOVA. In the absence of exogenous metabolic activation, ALA and DOVA were mutagenic in Salmonella typhimurium tester strain TA104. ALA was also mutagenic in S. typhimurium TA102, but not in TA98, TA100, or TA1535, indicating an oxidative mechanism. Removal of H(2)O(2) with catalase gave only partial protection, suggesting generation of other mutagenic species. Both ALA and DOVA damaged the DNA of Escherichia coli PQ37, inducing the SOS response detected by an increase in beta-galactosidase activity. These results verified the potential mutagenic activity of ALA and DOVA and reinforce the hypothesis that DNA damage induced by ALA may be associated with the development of HCC in individuals suffering from AIP.
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PMID:Genotoxicity of 5-aminolevulinic and 4,5-dioxovaleric acids in the salmonella/microsuspension mutagenicity assay and SOS chromotest. 1221 Oct 78

Although hydrogen peroxide (H(2)O(2)) induces proliferation of vascular smooth muscle cells, its role in endothelial cell proliferation is unclear. Our aim was to study the role of hydrogen peroxide in endothelial cell proliferation by overexpressing catalase. Human aortic endothelial cells were transduced with adenoviral vectors encoding beta-galactosidase (Adbetagal) or catalase (AdCat) or were exposed to diluent alone (control). Transgene expression was demonstrated by beta-galactosidase staining, Western analysis, and significantly increased enzyme activity in AdCat-transduced cells. Overexpression of catalase decreased DNA synthesis in AdCat compared with control and Adbetagal-transduced cells (536.8 +/- 31 vs. 1,875.1 +/- 132.9 vs. 1,347.5 +/- 93.7 dpm/well, respectively; P < 0.05 vs. control and Adbetagal). Six days after transduction with AdCat (multiplicity of infection = 50), cell numbers were significantly reduced (AdCat: 38 +/- 1.8% of cell counts in control, P < 0.05; and 45 +/- 2% of cell count in Adbetagal, P < 0.05). Incubation with aminotriazole 10 mmol/l, an inhibitor of catalase, prevented this effect. The number of apoptotic cells was increased one- and threefold 2 and 4 days, respectively, after transduction with AdCat. Exogenous administration of low concentrations of H(2)O(2) (50 microM) significantly increased cell proliferation, whereas it was inhibited by higher concentrations. These results suggest that H(2)O(2) is an important modulator of endothelial cell proliferation.
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PMID:Adenoviral-mediated overexpression of catalase inhibits endothelial cell proliferation. 1242 1

The catalase gene katA of Staphylococcus xylosus was cloned. It encodes a protein of 494 amino acids with a molecular mass of 56.9 kDa, closely related to monofunctional catalases. A katA mutant still showed a relatively high catalase activity demonstrating that S. xylosus possesses more than one enzyme. By Southern blot analysis using a katA probe, a second genetic locus distinct from katA was detected that probably contained the additional catalase gene. To analyse katA expression, a transcriptional fusion of the katA promoter region to a promoterless beta-galactosidase gene was integrated into the genome of S. xylosus. katA expression is induced upon entry into stationary phase, by oxygen and hydrogen peroxide. Iron and manganese depletion induced katA transcription. Comparing the resistance of S. xylosus wild-type and the katA mutant strain to hydrogen peroxide clearly showed that KatA is essential for S. xylosus to cope with hydrogen peroxide stress. Therefore, S. xylosus has at least two differentially expressed catalases.
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PMID:Characterisation of the katA gene encoding a catalase and evidence for at least a second catalase activity in Staphylococcus xylosus, bacteria used in food fermentation. 1243 14

Twenty-two isolates originating from the gut of healthy cultured turbot larvae in Norway were investigated using a polyphasic approach. Amplified fragment length polymorphism fingerprinting analysis showed that the isolates have typical patterns and form two main groups. Phylogenetic analysis revealed that the isolates belong to the gamma-Proteobacteria, with Vibrio hollisae as their closest neighbour. DNA-DNA hybridization, chemotaxonomic and phenotypic analyses further proved that these isolates represent a tight novel taxon that differs from currently described species in the family Vibrionaceae. It is proposed that these novel isolates be accommodated in a new genus, Enterovibrio gen. nov., with Enterovibrio norvegicus sp. nov. as the type species. Isolates were motile by a polar flagellum, positive for oxidase, catalase, arginine dihydrolase and beta-galactosidase, but negative for the Voges-Proskauer reaction. They produced indole, did not reduce nitrate and were resistant to the vibriostatic agent O/129. The DNA G+C content of E. norvegicus was 47.1-47.9 mol%. The type strain is E. norvegicus LMG 19839(T) (= CAIM 430(T)).
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PMID:Enterovibrio norvegicus gen. nov., sp. nov., isolated from the gut of turbot (Scophthalmus maximus) larvae: a new member of the family Vibrionaceae. 1250 62

Neptunia natans is a unique aquatic legume indigenous to tropical and sub-tropical regions and is nodulated symbiotically by rhizobia using an unusual infection process unlike any previously described. Previously, isolates of neptunia-nodulating rhizobia from Senegal were characterized as Allorhizobium undicola. Here we report on a different group of neptunia-nodulating rhizobia isolated from India. Sequencing of the 16S rDNA gene from two of these Indian isolates (strains J1T and J2) show that they belong in the genus Devosia rather than Allorhizobium. Currently, the only described Devosia species is D. riboflavina (family Hyphomicrobiaceae, order Rhizobiales). The complete 16S rDNA sequences of strains J1T and J2 are 95.9% homologous to the type strain, D. riboflavina LMG 2277T, suggesting that these neptunia-nodulating strains from India belong to a new Devosia species. This hypothesis was confirmed by further studies of polyphasic taxonomy (DNA-DNA hybridisation, TP-RAPD patterns, SDS-PAGE of cellular proteins, 16S rDNA RFLP patterns, carbon source utilisation, cellular fatty acid analysis and other phenotypic characterisations), all of which support the proposal that these neptunia-nodulating strains constitute a new Devosia species, which we name Devosia neptuniae sp. nov. These gram negative, strictly aerobic short rods are motile by a subpolar flagellum, positive for catalase, oxidase, urease and beta-galactosidase, can utilise several carbohydrates (but not organic acids) as carbon sources and contain C18:0 3-OH, cis-7 C18:1 11-methyl and cis-7 C18:1 as their major cellular fatty acids. Unlike D. riboflavina, the longer-chain C24:1 3-OH and C26:1 3-OH hydroxy fatty acids are not detected. The type strain of D. neptuniae is LMG 21357T (CECT 5650T). Assignment of this new taxon represents the fourth example in the literature of a non-rhizobial genus of bacteria capable of forming a bonafide dinitrogen-fixing root-nodule symbiosis with legume plants.
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PMID:Description of Devosia neptuniae sp. nov. that nodulates and fixes nitrogen in symbiosis with Neptunia natans, an aquatic legume from India. 1274 9

A multivariate model is proposed relating short-term biomarker measurements in Daphnia magna to chronic effects (21-d exposure) occurring at the population level (time to death, mean brood size, mean total young per female, intrinsic rate of natural increase, net reproductive rate, and growth). The results of the short-term exposure (48 h-96 h) to eight model toxicants (cadmium, chromium, mercury, tributyl tin, linear alkylsulfonic acid, sodium pentachlorophenolate, lindane, and 2,4-dichlorophenoxyacetic acid) on the following biomarkers were used for the multivariate model: digestive enzymes (amylase, cellulase, beta-galactosidase, trypsin, and esterase), enzymes of the intermediary metabolism (glycogen phosphorylase, glucose-6-phosphate dehydrogenase, pyruvate kinase, lactate dehydrogenase, and isocitrate dehydrogenase), cellular energy allocation (CEA) (protein, carbohydrate, and lipid content and electron transport activity), and DNA damage and antioxidative stress activity. Using partial least squares to latent structures (PLS), a two-component model was obtained with R2 of 0.68 and a Q2 value of 0.60 based on the combined analysis of a limited number of the 48- and 96-h biomarker responses. For the individual population-level responses, the R2 values varied from 0.66 to 0.77 and the Q2 values from 0.52 to 0.69. Energy-related biomarkers (cellular energy allocation, lipid contents, anaerobic metabolic activity--pyruvate kinase, and lactate dehydrogenase), combined with parameters related to oxidative stress (catalase) and DNA damage measured after 48 and 96 h of exposure, were able to predict long-term effects at higher levels of biological organization.
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PMID:A multivariate biomarker-based model predicting population-level responses of Daphnia magna. 1295 51

On the basis of phenotypic and genotypic characteristics, a novel species belonging to the genus Pedobacter is described. A facultatively psychrophilic, Gram-negative, aerobic, rod-shaped strain, A37(T), was isolated from alpine glacier cryoconite. The non-flagellated and non-spore-forming isolate grew over a temperature range of 1-25 degrees C, showed activities of oxidase, catalase, DNase, protease (gelatin, casein), amylase, beta-glucosidase, beta-galactosidase and beta-lactamase and degraded oil hydrocarbons. A distinct optimum temperature of 15 degrees C was observed for both protease production and oil hydrocarbon biodegradation. Analysis of 16S rDNA revealed that strain A37(T) represents a distinct taxon within PEDOBACTER: DNA from strain A37(T) showed only 19.7 % genetic relatedness to the DNA of Pedobacter piscium. The DNA G+C content was 43.4 mol%. Dominant fatty acids (51 %) were iso-15 : 0 2-OH and 16 : 1omega7c. The strain is assigned to a novel Pedobacter species, for which the name Pedobacter cryoconitis sp. nov. is proposed, with A37(T) (=DSM 14825(T)=LMG 21415(T)) as the type strain.
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PMID:Pedobacter cryoconitis sp. nov., a facultative psychrophile from alpine glacier cryoconite. 1313 9

After a finite doubling number, normal cells become senescent, i.e., nonproliferating and apoptosis resistant. Because Rel/nuclear factor (NF)-kappaB transcription factors regulate both proliferation and apoptosis, we have investigated their involvement in senescence. cRel overexpression in young normal keratinocytes results in premature senescence, as defined by proliferation blockage, apoptosis resistance, enlargement, and appearance of senescence-associated beta-galactosidase (SA-beta-Gal) activity. Normal senescent keratinocytes display a greater endogenous Rel/NF-kappaB DNA binding activity than young cells; inhibiting this activity in presenescent cells decreases the number of cells expressing the SA-beta-Gal marker. Normal senescent keratinocytes and cRel-induced premature senescent keratinocytes overexpressed manganese superoxide dismutase (MnSOD), a redox enzyme encoded by a Rel/NF-kappaB target gene. MnSOD transforms the toxic O()(2) into H(2)O(2), whereas catalase and glutathione peroxidase convert H(2)O(2) into H(2)O. Neither catalase nor glutathione peroxidase is up-regulated during cRel-induced premature senescence or during normal senescence, suggesting that H(2)O(2) accumulates. Quenching H(2)O(2) by catalase delays the occurrence of both normal and premature cRel-induced senescence. Conversely, adding a nontoxic dose of H(2)O(2) to the culture medium of young normal keratinocytes induces a premature senescence-like state. All these results indicate that Rel/NF-kappaB factors could take part in the occurrence of senescence by generating an oxidative stress via the induction of MnSOD.
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PMID:Involvement of Rel/nuclear factor-kappaB transcription factors in keratinocyte senescence. 1474 59

Reactive oxygen species (ROS) cause oxidative stress and aging. The catalase gene is a key component of the cellular antioxidant defense network. However, the molecular mechanisms that regulate catalase gene expression are poorly understood. In this study, we have identified a DNA replication-related element (DRE; 5'-TATCGATA) in the 5'-flanking region of the Drosophila catalase gene. Gel mobility shift assays revealed that a previously identified factor called DREF (DRE- binding factor) binds to the DRE sequence in the Drosophila catalase gene. We used site-directed mutagenesis and in vitro transient transfection assays to establish that expression of the catalase gene is regulated by DREF through the DRE site. To explore the role of DRE/DREF in vivo, we established transgenic flies carrying a catalase-lacZ fusion gene with or without mutation in the DRE. The beta-galactosidase expression patterns of these reporter transgenic lines demonstrated that the catalase gene is upregulated by DREF through the DRE sequence. In addition, we observed suppression of the ectopic DREF-induced rough eye phenotype by a catalase amorphic Cat(n1) allele, indicating that DREF activity is modulated by the intracellular redox state. These results indicate that the DRE/DREF system is a key regulator of catalase gene expression and provide evidence of cross-talk between the DRE/DREF system and the antioxidant defense system.
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PMID:Transcriptional regulation of the Drosophila catalase gene by the DRE/DREF system. 1498 56

Ion-exchange chromatography using commercial ionic supports is a commonly used technique for protein purification. However, selective adsorption of a target protein from a given extract onto commercial ion exchangers seems to be quite complex since they are designed to adsorb the maximum percentage of proteins with the opposite charge. In this paper, ion-exchanger supports with different activation degrees (from 1 to 40 micromol of amino groups per g of agarose) have been prepared and used for the purification of large proteins. These kinds of proteins have large surfaces to interact by many points with the support. Therefore, it was possible to purify large proteins as beta-galactosidase from Thermus sp. strain T2 from a crude extract from Escherichia coli or bovine liver catalase from a commercial preparation, with tailor-made ion-exchanger supports. A simple step of adsorption/desorption on lowly activated supports rendered both enzymes rather pure as confirmed by sodium dodecyl sulphate-polyacrylamide gel electrophoresis. Moreover, this strategy makes also easy the desorption step that requires rather low NaCl concentrations, which may become a serious problem for desorption of large proteins when using conventional supports, due to their ability of generating a very strong adsorption.
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PMID:Ion exchange using poorly activated supports, an easy way for purification of large proteins. 1511 25


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