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)

The total, free and unprecipitated activity of lysosomal (acid DNAase, acid RNAase, acid phosphate, acid beta-galactosidase) and peroxisomal (catalase, oxidase of D-amino acids) enzymes were studied in dog kidney cortex during storage of the tissues in solution of rheopolyglucin and under conservation of the kidney tissue by transrenal gas perfusion in hypothermia within 3 and 7 days. Labilization of lysosomal and peroxisomal membranes was observed during storage both in unperfused and in oxygenated kidney. Mechanisms of formation and functional significance of the alterations observed in structure of lysosomes and peroxisomes are discussed.
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PMID:[Labilization of lysosomal and peroxisomal membranes in the kidneys preserved by transrenal gas perfusion]. 1 22

Active 3C protease of poliovirus 1(M) was obtained when cloning and expressing fragment HindII-HindIII (bases from 5240 to 6056) of cDNA in vector pTTQ8 in E.coli cells. As shown, fragment 3D of polymerase covalently bound to 3C does not deprive the enzyme of its specific proteolytic activity. The absence of 26 N-terminal amino acids in 3C entails its inactivation. The recombinant 3C protease cleaved peptide bond Gln-Gly not only in virus polyprotein, but also in molecules of beta-galactosidase and bovine catalase.
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PMID:Recombinant poliovirus 3C protease. The enzyme application to protein specific fragmentation. 164 25

Oxygen free radicals are highly reactive species that damage DNA and cause mutations. We determined the mutagenic spectrum of oxygen free radicals produced by the aerobic incubation of single-stranded M13mp2 DNA with Fe2+. The Fe2(+)-treated DNA was transfected into component Escherichia coli, and mutants within the nonessential lac Z alpha gene for beta-galactosidase were identified by decreased alpha-complementation. The frequency of mutants obtained with 10 microM Fe2+ was 20- to 80-fold greater than that obtained with untreated DNA. Mutagenesis was greater after the host cells were exposed to UV irradiation to induce the SOS "error-prone" response. The ability of catalase, mannitol, and superoxide dismutase to diminish mutagenesis indicates the involvement of oxygen free radicals. The sequence data on 94 of the mutants establish that mutagenesis results primarily from an increase in single-base substitutions. Ninety-four percent of the mutants with detectable changes in nucleotide sequence were single-base substitutions, the most frequent being G----C transversions, followed by C----T transitions and G----T transversions. The clustering of mutations at distinct gene positions suggests that Fe2+/oxygen damage to DNA is nonrandom. This mutational spectrum provides evidence that a multiplicity of DNA lesions produced by oxygen free radicals in vitro are promutagenic and could be a source of spontaneous mutations.
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PMID:Mutagenic spectrum resulting from DNA damage by oxygen radicals. 170 14

The oxyR-encoded regulatory protein, OxyR, acts to induce the synthesis of a family of hydrogen peroxide-inducible proteins in Salmonella typhimurium and Escherichia coli. To further define the mechanism by which oxyR regulates the production of these proteins, we identified, mapped, and characterized oxyR-regulated promoters upstream from the S. typhimurium ahp genes (encoding an alkyl hydroperoxide reductase) and the E. coli katG gene (encoding catalase). A set of ahpC promoter deletions was constructed in vitro and analysis of these deletions revealed the location of sequences that are involved in oxyR-mediated induction of the ahpC gene product. DNase I protection studies of the ahpC promoter region revealed an oxyR-dependent footprint that overlapped the sequences found to be important for oxyR control. E. coli strains containing transcriptional fusions between the katG promoter and the lacZ gene showed strongly increased synthesis of beta-galactosidase in response to hydrogen peroxide treatment. This stimulation was found to be oxyR-dependent. DNase I protection studies of the katG promoter region revealed an oxyR-dependent footprint in the same location relative to the basal promoter elements as was observed with the ahpC promoter. Although both the ahpC and katG promoters were shown to bind the same factor, no strong sequence similarities were found between the two, or between the two and a third oxyR-dependent binding site upstream from the E. coli oxyR gene itself.
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PMID:Identification and molecular analysis of oxyR-regulated promoters important for the bacterial adaptation to oxidative stress. 269 40

In rats receiving a protein-poor diet for 60 days (4% caloric share of casein) the activity of beta-galactosidase, beta-N-acetyl glucose aminidase, acid proteinases, acid phosphatase, acetyl estherase, catalase, glutathione reductase, monoamine oxidase (MAO), glucose-6-phosphate dehydrogenase, and the content of malonic dialdehyde (MDA) were measured in the oral cavity mucosa. The authors observed the significant increase in MAO activity, and decrease in activities of beta-N-acetyl glucose aminidase, acetyl estherase, catalase, glutathione reductase, increased MDA contents. The changes in enzymatic activities had, to a several extent, an adaptive nature and were related to their reduced biosynthesis.
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PMID:[Enzymes of the oral mucosa in rats with protein deficiency]. 281 17

Retrovirus-mediated gene transfer was used to develop a method for introducing genes into primary cultures of adult rat hepatocytes. Subconfluent monolayers of hepatocytes, cultured in hormonally defined media on different matrix substrata, were infected with helper-free stocks of a replication-defective retrovirus that constitutively expresses high levels of beta-galactosidase. Retrovirus-mediated transduction was measured by two methods: (i) an in situ cytochemical stain that specifically detects the expression of viral expressed beta-galactosidase, and (ii) Southern blot analysis, which measures the relative copy number of integrated provirus. Maximal transduction efficiency of approximately equal to 25% was achieved when the cells were infected after 3 days in culture; matrix had little effect on transduction efficiency. Enzyme cytochemical (catalase and glucose 6-phosphatase) and peroxidase immunocytochemical (asialoglycoprotein and UDP-glucuronosyltransferase) analyses of the cultures indicated that greater than 95% of cells were hepatocytes. The demonstration of hepatocyte-specific organelles in cells expressing the viral-directed beta-galactosidase provided unambiguous evidence for the transduction of hepatocytes. These methods should be useful in the development of liver-directed somatic gene therapy and in the study of liver-specific gene regulation.
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PMID:Retrovirus-mediated transduction of adult hepatocytes. 283 28

Quantitative comparisons of the time course of biochemical and morphological changes induced by peroxisome proliferators resulting in low and high incidences of hepatic cancer have not been conducted previously under bioassay conditions. [4-Chloro-6-(2,3-xylidino)-2-pyrimidyl-thio]acetic acid (Wy-14,643) at 0.1% in the diet produced a much higher incidence of hepatic cancer in male rats than 1.2% di(2-ethylhexyl)phthalate (DEHP) in the diet. Both diets, however, caused similar degrees of peroxisome proliferation. To investigate this difference in carcinogenicity, H2O2-detoxification mechanisms and indices of oxidative damage were evaluated in male F-344 rats fed 1.2% DEHP or 0.1% Wy-14,643 for up to one year. DEHP or Wy-14,643 treatment increased hepatic catalase activity approximately 25% from 8 to 365 days. DEHP or Wy-14,643 treatment decreased hepatic glutathione peroxidase activity by 50% from 8 to 365 days. Glutathione concentrations were not affected by 151 days of DEHP or Wy-14,643 feeding. The similar effects of DEHP and Wy on H2O2 detoxification enzymes and glutathione concentrations suggests that these factors are not responsible for the widely different carcinogenicities of Wy-14,643 and DEHP. Hepatic vitamin E concentrations were 50% lower in rats receiving Wy-14,643 for 151 days as compared to rats fed DEHP or control diets. Lipofuscin, which was contained within lysosomes, was increased 3-fold after 39 days of DEHP and remained at this level up to 365 days of treatment. In comparison, lipofuscin was increased 4-fold after 18 days of Wy-14,643 and continued to accumulate in a linear manner reaching values 30-fold over controls after 365 days of treatment. DEHP treatment for 39-365 days increased the activities of the lysosomal enzymes alpha-fucosidase, beta-galactosidase and N-acetylglucosaminidase 50-100%. The same enzyme activities were increased approximately 4-fold after 39-365 days of Wy-14,643. Lysosomal cathepsin B activity was unchanged by DEHP but doubled by 151 and 365 days of Wy-14,643. Acid phosphatase activity was unchanged by DEHP but increased by 50% after 151 and 365 days of Wy-14,643. In addition, conjugated dienes were increased (approximately 45%) only in rats receiving Wy-14,643 for 151 and 365 days. These data show for the first time that the magnitude and time course of lipofuscin deposition, induction of lysosomal enzymes and conjugated diene accumulation, is correlated closely with the degree of carcinogenicity. Wy-14,643-induced decreases in hepatic vitamin E concentrations could contribute to the observed accumulation of conjugated dienes at later time points.(ABSTRACT TRUNCATED AT 400 WORDS)
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PMID:Relationship of oxidative damage to the hepatocarcinogenicity of the peroxisome proliferators di(2-ethylhexyl)phthalate and Wy-14,643. 292 96

Escherichia coli produces two distinct species of catalase, hydroperoxidases I and II, which differ in kinetic properties and regulation. To further examine catalase regulation, a lacZ fusion was placed into one of the genes that is involved in catalase synthesis. Transductional mapping revealed the fusion to be either allelic with or very close to katE, a locus which together with katF controls the synthesis of the aerobically inducible hydroperoxidase (hydroperoxidase II). katE was expressed under anaerobic conditions at levels that were approximately one-fourth of those found in aerobically grown cells and was found to be induced to higher levels in early-stationary-phase cells relative to levels of exponentially growing cells under both anaerobic and aerobic conditions. katE was fully expressed in air and was not further induced when the growth medium was sparged with 100% oxygen. Expression of katE was unaffected by the addition of hydrogen peroxide or by the presence of additional lesions in oxyR or sodA, indicating that it is not part of the oxyR regulon. When katF::Tn10 was introduced into a katE::lacZ strain, beta-galactosidase synthesis was largely eliminated and was no longer inducible, suggesting that katF is a positive regulator of katE expression.
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PMID:Transcriptional regulation of katE in Escherichia coli K-12. 304 91

A study of 216 noncapsular strains of Neisseria meningitidis isolated from patients and carriers received in the Meningococcus Reference Laboratory between 1978 and 1984 is reported. The characterization of the strains consisted of biochemical tests for the following characteristics used for the differentiation of Neisseria species: oxidase, catalase, and beta-galactosidase activities; sugar degradation; nitrate and nitrite reduction; DNase activity; polysaccharide production with 5% sucrose; aminopeptidase activity; and growth in Thayer-Martin and Catlin media. Of the strains studied, 50 showed characteristics of a new taxon recently described (Neisseria polysacchareae). Characteristics that differentiated these strains from meningococcal isolates were polysaccharide production with 5% sucrose, gamma-glutamylaminopeptidase activity, and a requirement for cysteine or cystine for growth in Catlin medium. All of the N. polysacchareae strains identified were isolated from the nasopharynx of healthy carriers.
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PMID:Characterization of Neisseria polysacchareae sp. nov. (Riou, 1983) in previously identified noncapsular strains of Neisseria meningitidis. 308 73

Fifty-two strains found to belong to Flavobacterium meningosepticum on the basis of DNA-DNA hybridization analyses were characterized and found to be phenotypically homogeneous. All strains were oxidase, catalase, indole, gelatinase and beta-galactosidase positive, and produced acid from glucose, mannose, fructose, maltose and mannitol; nitrate was not reduced. F. meningosepticum could be differentiated from Flavobacterium group IIb by its ability to produce beta-galactosidase, and by the latter taxon's ability to produce a bright yellow pigment in contrast to the weak or non-existing pigmentation of F. meningosepticum. Phenotypic characteristics that could differentiate between the two main DNA relatedness groups of F. meningosepticum were not discovered, wherefore a subdivision of the present species into two species cannot be recommended. Strains from the DNA relatedness groups comprising 19 of 20 CSF isolates were found to be able to grow at 40 degrees C and to produce a weak yellow pigment; in contrast, strains from the three other DNA relatedness groups were unable to grow at 40 degrees C and produced no pigment.
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PMID:Phenotypic characterization of Flavobacterium meningosepticum strains identified by DNA-DNA hybridization. 356 17


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