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:3.1.21.3 (deoxyribonuclease)
1,528 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Whole sheets of plasma membrane, each with their attached flagellum, were purified from Trypanosoma brucei. The method devised for their isolation included a new technique of cell breakage that used a combination of osmotic stress followed by mechanical sheer and avoided the problem of extreme vesiculation as well as the trapping of organelles in cell 'ghosts'. The purified membranes all contained the pellicular microtubular array. The antigenic surface coat was completely released from the plasma membrane during the isolation procedure. The membranes had a very high cholesterol/phospholipid ratio (1.54). A large proportion (42%) of the cellular DNA was recovered in the plasma-membrane fraction unless a step involving deoxyribonuclease treatment, which decreased the DNA content to less than 13%, was included before secrose-density gradient centrifugation. This step also aided the separation of plasma membranes from other cellular components. The ouabain-sensitive Na+ + K+-stimulated adenosine triphosphatase and adenylate cyclase co-purified with the plasma membranes. Although 5'-nucleotidase was thought to be a plasma-membrane component, it was easily detached from the membrane. The purified membranes were essentially free of L-alanine-alpha-oxoglutarate aminotransferase, L-asparte-alpha-oxoglutarate aminotransferase, malate dehydrogenase, oligomycin-sensitive adenosine triphosphatase, glucose 6-phosphatase, Mg2+-stimulated p-nitrophenyl phosphatase and catalase.
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PMID:The isolation and partial characterization of the plasma membrane from Trypanosoma brucei. 48 94

Both virulent (V) and avirulent (AV) strains of Actinomyces viscosus T14 are capable of colonizing the oral cavity of gnotobiotic rats, but only T14-V causes destructive periodontal disease. The basis for this difference in in vivo pathogenicity has not been adequately defined. In the present study we compared the capacities of T14-AV and T14-V to provoke in vitro extracellular release of lysosomal constituents from human polymorphonuclear leukocytes (PMNs). In serum-free cultures, viable T14-V but not T14-AV stimulated discharge of PMN lysosomes. The release response was correlated with PMN phagocytic activity; thus, PMNs readily ingested T14-V but not T14-AV. To explain these differences in PMN-bacteria interactions, subcellular fractions of T14-AV or T14-V were incubated with PMNs. A crude, insoluble sonic extract derived from T14-V caused PMN lysosome release, but a similar fraction from T14-AV was inactive. However, following extensive washing and treatment with deoxyribonuclease or sodium dodecyl sulfate, cell wall fractions of T14-AV stimulated lysosome release. These procedures apparently removed an extracellular polysaccharide slime which is synthesized by T14-AV but not by T14-V. There was a significant reduction in the capacities of viable T14-V or cell wall fractions of T14-V or T14-AV to provoke PMN lysosome release when these agents were preincubated with a slime material isolated from T14-AV. This inhibitory influence of slime was overcome by the addition of fresh or heated (56 degrees C, 30 min) serum to the PMN-bacteria cultures. The data suggest a relationship between the abilities of the avirulent and virulent strains of A. viscosus T14 to act as periodontal pathogens in vivo and to serve as stimuli for PMN lysosome release in vitro.
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PMID:Interaction of inflammatory cells and oral microorganisms. VII. In vitro polymorphonuclear responses to viable bacteria and to subcellular components of avirulent and virulent strains of Actinomyces viscosus. 68 37

Cells of Bacillus subtilis heated in high concentrations of sodium dodecyl sulfate (5%) and then washed free of detergent with a hot salt solution (80 C) become structurally reorganized into regions of densely compacted cytoplasm (termed zebras) and regions of sparsely filled material (termed spaces). Size distribution studies of zebras indicate that division-suppressed mutants and wild-type cells both yield zebras of comparable length. Similarly the lengths of zebras found in populations emerging from spores are uniform in one-, two-, three-, and four-zebra-containing cells. In contrast, the length of spaces is slightly larger than that of zebras and is unusually large in two-zebra-containing cells. The locations of zebras and spaces along cell length have been studied in spore out-growth populations. A statistical procedure developed previously in genome location investigations was used to analyze the location of zebras along cell length. The data indicate that as cells elongate, new sites arise where the cell contents are strongly bound to the cell surface. Within filament populations produced by division-suppressed mutants there is a linear relationship of mean filament length and zebra number per filament. These data indicate that cytoplasm in filaments with no obvious structural compartmentalizations may be organized into units associated with particular regions of cell surface. The attachment of cell contents to the cell surface may involve deoxyribonucleic acid. Zebra-containing cells digested with proteolytic enzyme and ribonuclease are converted to cells that contain a crystalline-like granule fixed at the location of each zebra. Exposure to deoxyribonuclease mobilizes these granules within the cell wall.
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PMID:Cellular organization of Bacillus subtilis: sodium dodecyl sulfate-induced cell partitioning into zebra structures. 82 Jun 87

The proteins of the secretory granules of the rat parotid gland were characterized by sodium dodecylsulfate gel electrophoresis, by chromatography of [3-H]proline-labeled proteins on DEAE-cellulose and by amino acid analysis. Sodium dodecylsulfate gel electrophoresis of the secretory granule content showed five principal proteins and a limited number of minor components. Only two of the principal bands could be identified as known secretory enzymes of the parotid gland. One was identified as the alpha-amylase and one as deoxyribonuclease. Peroxidase and ribonuclease form minor portions of the secretory proteins. The other three major proteins constitute, together, about 60% by weight, of the secretory granule content proteins. Of these, one which represents more than 30% of the total granule protein was found to contain uniquely high amounts of leucine residues (21 mole%). Another one of these principal proteins was relatively rich in cysteine residues (7 mole%). The fifth principal protein was found to contain high amounts of proline (28 mole%) glutamic acid (17 mole%) and glycine (18 mole%) residues. Its amino acid composition was very similar to that of the proline-se granules. This protein, however, differed from the "membranous" proline-rich proteins by several criteria. Two minor glycoproteins of the secretory granule content were also found to be rich in proline residues (37 mole%). As with the other proline-rich proteins of the granule, they contained no sulphur-containing amino acids, stained faintly pink with Coomassie Blue and were underestimated by the Lowry method. They differ however, from all the other proline-rich proteins of the granule by having a significantly higher content of threonine, less glycine (9 mole%) and much less glutamic acid (3 mole%). Of the principal proteins, only the deoxyribonuclease and the half-cystine-rich proteins were positively stained by periodic acid Schiff staining. The possible functions of the leucine-rich, the half cystine-rich and the various proline-rich proteins are discussed.
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PMID:The proteins of the content of the secretory granules of the rat parotid gland. 112 45

The effect of convulsions, induced by flurothyl, on RNA synthesis in purified unfractionated nuclei and the cytoplasm of rat cerebral cortex was studied by using a double-label technique involving injection of [3H]- and [14C]-orotate intracisternally. 2. Intact RNA was extracted in 80% yield by an enzymic method by using a proteinase in the presence of sodium dodecyl sulphate followed by deoxyribonuclease. Electrophoresis on 1.5% polyacrylamide-0.5% agarose gels revealed the presence of giant nuclear RNA of size up to approx. 300X 10(6) daltons and mRNA of maximal mol.wt. 9 X 10(6)-16 X 10(6). 3. Nuclear RNA synthesis was decreased to 27% in the first 15 min after convulsions but rapidly increased, so that at 1 1/2 h it was 124% of the control, and at 6 h 147%. 4. Labelling of cytoplasmic RNA was decreased to 15% at 15 min after convulsions but had not recovered to control values by 6 h. 5. Analysis of radioactive gel patterns and the 3H/14C ratio at six time-points (15 min-6h) showed that the major effect was inhibition of the processing of heterogeneous nuclear RNA resulting in a sharp decline in the export of newly synthesized RNA from the nucleus. 6. Cytoplasmic RNA patterns indicated that specific messengers were synthesized at different times during the recovery of the cell after convulsions.
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PMID:The effect of convulsions induced by flurothyl on ribonucleic acid synthesis in rat cerebral cortex during the recovery phase. 122

The genes of the AccI restriction-modification system specific for GT(A/C) (G/T)AC were cloned from the chromosomal DNA of Acinetobacter calcoaceticus, and their nucleotides sequenced. The restriction and modification genes coded for polypeptides with calculated molecular weights of 42,494 and 63,078, respectively. Both the enzymes were coded by the same DNA strand and the restriction gene was upstream of the methylase gene, separated by 2 bp. The restriction gene was significantly expressed in E. coli cells, so that the AccI restriction endonuclease could be purified to homogeneity. Analysis by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and gel filtration indicated that the catalytically active form of the endonuclease was tetrameric. Sequence comparison with related enzymes indicated that AccI methylase contained a segment of tetra-amino acids, NPPY, characteristic of N6-adenine methylases. In addition, some homologous regions were found in the sequence of HincII methylase specific for GT(C/T) (A/G)AC.
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PMID:Cloning and nucleotide sequences of the AccI restriction-modification genes in Acinetobacter calcoaceticus. 136 3

A set-up for casting fluorescent indicator agarose gels on ultrathin polyacrylamide microelectrophoresis gel media (Pharmacia PhastGel media) is described. The zymogram system allows a rapid and sensitive detection of deoxyribonuclease in various gel media, following isoelectric focusing, native and sodium dodecyl sulfate-polyacrylamide gel electrophoresis.
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PMID:Deoxyribonuclease zymography adapted to the precast PhastGel electrophoresis media. 169 91

Glucocorticoid-induced lymphocyte cell death is a programmed process which is thought to involve the calcium-dependent degradation of DNA into multiples of 180 basepairs, characteristic of internucleosomal degradation. We have used the glucocorticoid-sensitive mouse lymphoma cell line S49.1 [wild-type (wt)] and the glucocorticoid-resistant cell line S49.22r (nt-) to evaluate the role of both glucocorticoid receptors and calcium in the regulation of internucleosomal DNA degradation and expression of calcium-dependent deoxyribonuclease activity. DNA was isolated from untreated (control) and dexamethasone (dex)-treated viable cells and analyzed for internucleosomal DNA degradation by agarose gel electrophoresis, followed by ethidium bromide staining. Glucocorticoid treatment resulted in substantial internucleosomal DNA degradation in wt cells, but not in nt- cells. This effect was inhibited by coincubation of cells with dex and the glucocorticoid receptor antagonist RU486. In contrast to the glucocorticoid response, administration of either of two calcium ionophores, ionomycin or A23187, produced internucleosomal degradation of DNA in both wt and nt- cells, although the latter were less sensitive to ionophore treatment. Interestingly, A23187 treatment also resulted in a loss of cell viability in HeLa S3 cells, a cell line that does not exhibit glucocorticoid-induced apoptosis. No internucleosomal DNA degradation was detected in HeLa S3 cells killed by A23187. To determine whether similar nucleases are associated with this internucleosomal DNA degradation resulting from both glucocorticoid and calcium ionophore treatment, 0.3 M NaCl nuclear protein extracts were prepared from control and treated cells and analyzed for protein composition or nuclease activity. To assay for nuclease activity, nuclear extracts were electrophoresed in sodium dodecyl sulfate-polyacrylamide gels impregnated with [32P]DNA. Nuclease activity was detected by removal of sodium dodecyl sulfate from the gel, activation with calcium, and subsequent visualization of the loss of [32P]DNA by autoradiography. Dex treatment of wt cells resulted in the appearance of several proteins within the mol wt range of 12-18 kDa, only one of which (16-18 kDa) exhibited calcium-dependent nuclease activity. The appearance of these proteins in nuclear extracts was inhibited by coincubation of glucocorticoid-treated cells with RU 486. Glucocorticoid treatment did not result in the appearance of nuclease activity in nuclear extracts from nt- cells. Interestingly, A23187 or ionomycin treatment resulted in an increase in activity of the 16- to 18-kDa nuclease in both wt and nt- cells. These findings indicate that both glucocorticoid receptors and calcium may share common features in the regulation of apoptosis in lymphoid cells.
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PMID:Similar actions of glucocorticoids and calcium on the regulation of apoptosis in S49 cells. 194 10

Epstein-Barr virus-associated deoxyribonuclease (EBV-DNase) was purified to homogeneity, as determined by silver staining, sequential column chromatography, and FPLC from Raji and P3HR-1 cells treated with 12-O-tetradecanoyl-phorbol-13-acetate and sodium butyrate. This viral protein was immunogenic and elicited high neutralization titer sera in rabbits. By silver staining of SDS-PAGE, Western immunoblot, and radioimmunoprecipitation using NPC patient sera and both polyclonal and monoclonal antibodies, the EBV DNase was identified as a 58K protein. The potential presence of two EBV DNases was also discussed.
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PMID:Chromatographic purification and characterization of EBV DNase from chemically induced lymphoid cells. 215 13

The genes of the BanI restriction-modification system specific for GGPyPuCC were cloned from the chromosomal DNA of Bacillus aneurinolyticus IAM1077, and the coding regions were assigned on the nucleotide sequence on the basis of the N-terminal amino acid sequences and molecular weights of the enzymes. The restriction and modification genes coded for polypeptides with calculated molecular weights of 39,841 and 42,637, respectively. Both the enzymes were coded by the same DNA strand. The restriction gene was located upstream of the methylase gene, separated by 21 bp. The cloned genes were significantly expressed in E. coli cells, so that the respective enzymes could be purified to homogeneity. Analysis by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and gel filtration indicated that the catalytically active form of the endonuclease was dimeric and that of the methylase was monomeric. Comparison of the amino acid sequences revealed no significant homology between the endonuclease and methylase, though both enzymes recognize the same target sequence. Sequence comparison with other related enzymes indicated that BanI methylase contains sequences common to cytosine-specific methylases.
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PMID:Cloning and nucleotide sequences of the BanI restriction-modification genes in Bacillus aneurinolyticus. 235 38


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