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:3.1.25.1 (deoxyribonuclease)
1,471 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Zeya, H. I. (University of North Carolina, Chapel Hill), and J. K. Spitznagel. Cationic proteins of polymorphonuclear leukocyte lysosomes. I. Resolution of antibacterial and enzymatic activities. J. Bacteriol. 91:750-754. 1966.-A lysosomal fraction from polymorphonuclear (PMN) leukocytes of guinea pig peritoneal exudate was subjected directly to electrophoresis on cellulose acetate paper treated with cetyltrimethyl ammonium bromide. The Iysosomal components resolved into seven bands moving towards the cathode. Assay of the eluted bands showed that the antibacterial activity was distinct from lysosomal enzymes and was associated with three cationic components (bands I, II, and III) which migrated most rapidly towards the cathode, ahead of lysozyme ribonuclease and deoxyribonuclease. Qualitatively, the antibacterial components appeared to be rich in arginine. The antibacterial components were absent in the pherograms of nuclear fractions of PMN leukocytes and in supernatant fractions that remained after lysosomes were removed from cell homogenates by centrifugation at 8,000 x g.
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PMID:Cationic proteins of polymorphonuclear leukocyte lysosomes. I. Resolution of antibacterial and enzymatic activities. 593 73

Techniques utilizing Feulgen, azure B bromide, methyl green-pyronin, gallocyanin chromalum and cresyl violet stains have been modified and adapted for visualizing nucleic acids in 0.5-2.0 micrometer sections of tissues embedded in glycol methacrylate (GMA). Methods for evaluating the stain specificity for DNA and RNA using deoxyribonuclease and ribonuclease digestions, aldehyde blocking, and acid extractions are also described. The specificity of the stains in GMA embedded tissues is comparable to that reported for paraffin-embedded tissues.
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PMID:Glycol methacrylate in light microscopy: nucleic acid cytochemistry. 616 20

An endodeoxyribonuclease has been purified from nuclei of bovine small intestinal mucosa to a homogeneous state by a procedure involving affinity chromatography on heparin-agarose. The endonuclease, which was found to be bound to chromatin, has a pH optimum of 5.4. It requires Mn2+ or Co2+ for activity and its maximum activity with Mg2+ is about 80% of that with Mn2+. Its activity is strongly inhibited by sulfhydryl-blocking agents, and by ethidium bromide. The enzyme does not attack RNA and is inhibited by it. Its isoelectric point is 8.5 +/- 0.1, and its molecular weight is 49,000 +/- 3,000, determined by sucrose gradient sedimentation and gel filtration on Sephadex G-100. Polyacrylamide gel electrophoresis in the presence of sodium dodecyl sulfate indicated that the enzyme is composed of two nonidentical subunits with molecular weights of 30,000 and 23,000. The enzyme catalyzes the endonucleolytic cleavage of circular duplex ColE1 DNA via single strand scissions from the initial stage of degradation. The average size of the limit products of native phage T7 or ColE1 DNA is about 2,000 to 1,500 base pairs, estimated by neutral sucrose gradient sedimentation or agarose gel electrophoresis. The enzyme degrades denatured DNA about 20 times faster than native DNA. The products contain 5'-phosphoryl and 3'-hydroxyl termini, and all four deoxymononucleotides are present in almost equal amounts at the 5'-termini.
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PMID:Purification and properties of an endodeoxyribonuclease from nuclei of bovine small intestinal mucosa. 625 82

An apurinic endonuclease activity has been characterized in yeast mitochondrial. It is dependent on Mg2+, stimulated by about 50% in the presence of 50 mM NaCl and inhibited at higher NaCl concentrations. It is located in the inner mitochondrial membrane and requires high concentrations of detergent (1.5-3% Triton X-100) to be extracted. The same treatment extracts several other endonuclease activities: the two Mg2+-dependent endonuclease activities cleaving double-stranded DNA at pH 7.5 and 5.4 respectively, the ethidium-bromide-stimulated endonuclease activity, the endonuclease activity cleaving single-stranded DNA at pH 7.l5 [Jacquemin-Sablon et al. (1979) Biochemistry, 18, 119-127], and a manganese-stimulated deoxyribonuclease activity cleaving double-stranded DNA at pH 7.5 which has been discovered during the present work. Another endonuclease activity cleaving double-stranded DNA at pH 7.5 in the presence of Mg2+, slightly stimulated by low NaCl concentrations and inhibited by ethidium bromide is extracted from the membrane pellet remaining after the treatment with 1.5% Triton X-100 by a second treatment with 1.5% Triton X-100 plus 1 M KCl. The presence in the mitochondrial membrane of this apurinic endonuclease activity indicates that, like nuclear and prokaryotic DNA, yeast mitochondrial DNA is also subject to specialized repair systems.
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PMID:Endonucleases in yeast mitochondria: apurinic and manganese-stimulated deoxyribonuclease activities in the inner mitochondrial membrane of Saccharomyces cerevisiae. 628 1

The effect of various metabolic inhibitors (carbonylcyanid-m-chlorophenylhydrazone, nigericin, valinomycin, dicyclocarbodiimide, arsenate, NaF, etc.) and lipid-soluble synthetic ions (tetraphenylphosphonium bromide and tetraphenylboron sodium) on deoxyribonucleic acid (DNA) entry during transformation of Ca2+-treated Escherichia coli cells with plasmid DNA and on cell viability was investigated. In contrast to intact cells, Ca2+-treated E. coli cells were permeable to nigericin, valinomycin, and the other drugs tested. The inhibitors differentially affected [14C]proline active transport, and whereas some drugs inhibited transformation, the effects did not correlate with the effects on transport. The most potent inhibitors of transformation were nigericin, dicyclocarbodiimide, and tetraphenylboron sodium. Carbonylcyanid-m-chlorophenylhydrazone, tetraphenylphosphonium bromide, and valinomycin were relatively inactive. Tetraphenylboron sodium- and nigericin-treated cells bound were plasmid [14C]DNA in the deoxyribonuclease-resistant form than the control and other sample cells. Nevertheless, te penetration of exogenous plasmid DNA into the cell was greatly reduced, at least in case of nigericin. Unlike the other drugs, nigericin and dicyclocarbodiimide drastically affected the cell viability, the former within very short times of interaction. It is concluded that proton motive force does not play any significant role in DNA entry into Ca2+-treated E. coli cells. The results also suggest that adenosine 5'-triphosphate is not required for DNA entry either. The inhibitory effect of certain drugs is discussed in terms of structural perturbations induced by the drugs in cell envelope membranes.
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PMID:Effect of metabolic inhibitors on entry of exogenous deoxyribonucleic acid into Ca2+-treated Escherichia coli cells. 701 27

Four nuclear thermosensitive mutants have been obtained in which induction of up 100% cytoplasmic petite mutants (rho-) is observed upon cell incubation at 36 degrees C. For a given incubation time at 36 degrees C, the percentage of rho- is increased by preliminary gamma-ray irradiation. Under these conditions, the induction of rho- is a linear function of the irradiation dose. The retention of genetic information by rho- and of mitochondrial DNA synthesis in vivo and in vitro exclude that the mutants are deficient in the replication of mitochondrial DNA. The degradation of mitochondrial DNA labeled with [3H]dTTP in isolated mitochondria, has been monitored at 26 degrees C and at 36 degrees C after addition of 0.5% Triton X-100 in the presence or in the absence of ethidium bromide. In assays carried out at 26 degrees C, the degradation of mitochondrial DNA is similar in the parental strain and in the mutant gamma s rho 2. However, at 36 degrees C, the degradation of mitochondrial DNA is slower in the mutant. We have shown that a mitochondrial membrane deoxyribonuclease acting on double-stranded DNA at acid pH is thermosensitive in the mutant. Analysis of the meiotic segregants of a tetrad issued from the cross of the mutant with an isogenic parental strain shows co-segregation of rho- induction and of nuclease thermosensitivity in a 2:2 Mendelian pattern. These results suggest that a mitochondrial deoxyribonuclease is involved in the repair of damages caused to mitochondrial DNA by elevated temperature and by x-rays.
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PMID:Repair of mitochondrial DNA in Saccharomyces cerevisiae. Induction of cytoplasmic petite mutants in a nuclear mutant exhibiting thermosensitive mitochondrial deoxyribonuclease activity. 703 19

The interaction of human platelets and Candida albicans was studied. Platelet-rich plasma was obtained from freshly drawn blood or outdated platelet concentrates. From the platelet-rich plasma, a platelet extract was derived which stimulated germ tube formation by C. albicans when incubated with yeast cells at 37 degrees C. The active component(s) was heat stable, trypsin sensitive, and ribonuclease and deoxyribonuclease insensitive, and possessed cationic properties since it readily attached to carboxymethyl-Sephadex. The active component(s) seemed to bind to heparin also, since germ tube-promoting activity was eluted from a heparin-cyanogen bromide-activated Sepharose 4B column. In addition, platelet-derived growth factor (Collaborative Research, Inc.) stimulated germination when incubated with low amounts (0.4% final concentration) of bovine calf serum. The aggregation of platelets, prepared as platelet-rich plasma by C. albicans cell wall or alkali-extracted cell wall fractions, was also studied. Aggregation of platelets was observed when cell wall or cell wall fractions were incubated with platelet-poor plasma at 37 degrees C for 20 min and then added to platelet-rich plasma. The component of platelet-poor plasma which promoted aggregation of platelets by C. albicans cell wall or alkali-extracted fractions was inactivated at 56 degrees C (30 min) and by cobra venom factor, indicating a role for the alternate complement pathway in the aggregation response.
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PMID:Platelet interactions with Candida albicans. 703 46

We previously described a yeast-mitochondrial deoxyribonuclease (EtdBr DNAase), whose activity is stimulated by ethidium bromide. In this paper, we have compared the ability of a series of phenanthridinium derivatives to activate the EtdBr DNAase "in vitro" and their efficiency in inducing "petite" mutants in the yeast S. cerevisiae. Kinetics studies, in the absence or the presence of SDS, were first carried out to compare the penetration rates of the various compounds. Dose--response curves were then established to quantify their mutagenic efficiencies. From these data, a linear correlation was established between the level of EtdBr DNAase activation produced by a drug and its mutagenic efficiency, thus demonstrating that the two processes display similar drug-structural requirements. These results suggest that the EtdBr DNAase might be involved in the induction of petite mutations by these derivatives.
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PMID:Yeast mitochondrial deoxyribonuclease stimulated by ethidium bromide. III. Possible invovlement in the induction of "petite" mutation by phenanthridinium derivatives. 739 39

Our recent structure-activity analysis of Fpg protein of Escherichia coli, using oligodeoxynucleotides containing various 8-oxopurine derivatives, has allowed us to postulate an enzyme mechanism involving protonation of 8-oxoguanine at O-6 and nucleophilic attack of the deoxyribose moiety at C-1' leading to the formation of an enzyme-substrate Schiff base intermediate (Tchou, J., Bodepudi, V., Shibutani, S., Antoshechkin, I., Miller, J., Grollman, A. P., and Johnson, F. (1994) J. Biol. Chem. 269, 15318-15324). In this paper, sodium cyanoborohydride has been used to convert the transient intermediate to a covalent enzyme-DNA complex. The location of the active site of Fpg protein is further delineated using two approaches. 1) A radiolabeled DNA substrate is used to tag the active site of Fpg protein, using sodium cyanoborohydride. The active site is mapped to the first 73 amino acid residue fragment by cyanogen bromide cleavage analysis. 2) A maltose-binding protein fusion system is used to generate amino-terminal modifications of Fpg protein to explore the role of the amino-terminal region in DNA binding and catalysis. Results support the conclusion that the active site of Fpg protein is located at or near the amino terminus. Thus, Fpg protein may act in a similar fashion as T4 endonuclease V, a DNA repair enzyme that uses its amino-terminal alpha-amino group of threonine to carry out catalysis via Schiff base formation (Dodson et al., 1993).
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PMID:The catalytic mechanism of Fpg protein. Evidence for a Schiff base intermediate and amino terminus localization of the catalytic site. 774 6

3-Amino-1,4-dimethyl-5H-pyrido[4,3-b]indole (Trp-P-1) is a mutagen/carcinogen derived from cooked foods which enhances the induction of mutations and chromosome aberrations by UV without microsomal activation. These co-mutagenic effects are considered to arise from inhibition of DNA excision repair at the incision step. However, the inhibition mechanism has not been clarified. In this study we show, using agarose gel electrophoresis, that Trp-P-1 inhibits incision by T4 endonuclease V, which cleaves DNA at the site of cyclobutane dimers. Trp-P-1 also inhibits the binding of this enzyme to UV-damaged DNA in a gel shift assay. In addition, the results of DNA unwinding assay with topoisomerase I suggest that Trp-P-1 intercalates into DNA molecules. The known intercalators ethidium bromide and acriflavine demonstrate similar effects in these experiments. However, 2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP), which showed no co-mutagenic effects in our previous study, does not demonstrate such effects. These results suggest that Trp-P-1 changes DNA conformation by intercalation, causing inhibition of binding of repair enzymes to UV-damaged DNA, and this in turn leads to inhibition of DNA excision repair and to co-mutagenic effects.
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PMID:3-Amino-1,4-dimethyl-5H-pyrido[4,3-b]indole (Trp-P-1) inhibits the binding activity of T4 endonuclease V to UV-damaged DNA. 868 43


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