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:3.1.21.1 (DNase)
7,655 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

By sequential acid treatment, gel filtration and KM-cellulose sorption a 18--20-fold purified preparation of ribonuclease with a yield of 50--60% was obtained from the culture liquid filtrate of Actinomyces rimosus 994. The preparation had a high specific activity of 450,000--600,000 units/mg protein, contained 85--98% protein, insignificant amounts of carbohydrates and hydroxytetracycline, and no quantities of DNase, phosphomonoesterases, phosphodiesterase or proteases. In RNA degradation (preparation of the total yeast RNA of the Sigma Co.) optimal results were obtained at 50 degrees C and pH 7.0--7.2 in phosphate buffer and 7.6--8.0 IN Tris-HCl buffer. The preparation was stable at high temperatures (80--100 degrees) in the wide pH range and during storage in the lyophilized form and in buffer solutions. RNase effect was inhibited by zinc, copper, iron and cobalt cations and activated by beta-mercaptoethanol, citrate and EDTA. Protamine sulphate and urea in low concentrations (0.01% and 1--4 M, respectively) accelerated and in high concentrations (1% and 8 M, respectively) terminated the enzyme reaction. With respect to many properties RNase from Act. rimosus 994 was similar to extracellular RNases, produced by other actinomycetes and fungi.
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PMID:[Preparation of extracellular ribonuclease form Actinomyces rimosus 994]. 3 16

Gallo blue E, C. I. No. 51040, Mordant Violet 54, furnishes a blue black nuclear stain when applied to tissue sections in the form of its moderately stable iron lakes. This coloring combined well with such counterstains as orange G and eosin B. The Van Gieson stain tends to decolorize mucins, cartilage, and mast cells previously stained with this dye. Its aluminum lake solutions tend to gel in a few minutes to 24 hours depending on the solvent used and the amount of Al3+ present. Aluminum lake solutions give a moderately good blue to dark blue nuclear stain and a brilliant purplish red to dark purple stain to a variety of epithelial and connective tissue mucins. Acid dye counterstains are poorly tolerated. With either lake, nuclear staining is abolished by deoxyribonuclease digestion or relatively short mineral acid extraction of DNA.
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PMID:Iron and aluminum lakes of Gallo blue E as nuclear and metachromatic mucin stains. 5 27

Using hepatectomized rats, it was shown that immediately after a partial liver removal the Kupffer macrophages were accumulated. At the maximal mitotic activity (36 hours following partial hepatectomy), the relative amount of Kupffer cells keeps low, but 72 hours later turns out to be higher again. The periodic changes of the Kupffer cell amount in hepatectomized rats are accompanied by remarkable increase (by 1.5--3 times) of free and total lysosomal enzymes (acid DNAase, DNAase, cathepsin D). The activation of the Kupffer macrophage lysosomes goes ahead of labilization of hepatocyte lysosomal membranes. The blockade of mononuclear phagocyte system by means of carbonate iron in an early prereplicative period leads to an as long as 10--12 hours retardation of hepatocyte proliferation. The role of the Kupffer macrophages in reparative liver regeneration is discussed.
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PMID:[Change in the state of the lysosomes in isolated Kupffer cells and hepatocytes in the process of liver reparative regeneration]. 72 76

Treatment of growing cultures of Mycobacterium smegmatis with alkylating agents (methyl methanesulphonate, ethyl methanesulphonate, nitrogen mustard, or mitomycin C) or with ultraviolet light resulted in enhanced specific activities of a DNA polymerase and of an ATP-dependent deoxyribonuclease. Similar results had previously been obtained with hydroxyurea and with iron limitation. The three of these treatments which were tested (methyl methanesulphonate, mitomycin C and hydroxyurea) produced strand breaks or alkali-labile regions in the DNA of this organism. The increased enzyme activities could be prevented by simultaneous treatment with inhibitors of protein synthesis. In contrast, treatment of the cultures with intercalating agents (ethidium bromide, acridine orange, or proflavine), 5-fluorouracil, caffeine, or nalidixic acid, inhibited DNA synthesis without increasing the enzyme activities. These treatments did not produce strand breaks in the DNA of this organism. The results support the hypothesis that, in M. smegmatis, damage to DNA induces increased synthesis of enzymes associated with DNA repair.
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PMID:Increased DNA polymerase and ATP-dependent deoxyribonuclease activities following DNA damages in mycobacterium smegmatis. 84 85

The diagnosis of obligately aerobic Gram-negative rods in the clinical laboratory may encounter difficulties since media used for Enterobacteriacae are only partially usable for the diagnosis of this group of bacteria (Psuedomonas, Xanthomonas, Alcaligenes, Achromobacter, Brucella, Bordetella, Flavobacterium, Moraxella, Acinetobacter, and some still unnamed taxa). We have developed a diagnostic scheme, based on recent publications in the field and representing an extension of earlier tables from this and other laboratories, which attempts to classify a maximal number of obligately aerobic Gram-negative rods with a minimal number of tests. The scheme, employed on 4051 strains, used blood agar and MacConkey Agar as isolation media. Growth characteristics on these media and microscopic morphology may be of help, but only the type of growth on Triple Sugar Iron (or Kligler's) Agar is characteristic for the group as a whole (no growth in the butt, alkalinization or no pH change on the slant). A primary identification series employs tests for oxidase (Kovacs), oxidation of glucose and xylose (in OF medium), deoxyribonuclease and indole (in DNase Test Agar with Methyl Green), nitrate reduction (in Indole Nitrite Medium), motility (hanging drop), and fluorescein production (on Flo Agar). Results of Kirby-Bauer antimicrobial sensitivity testing serve as additional (colistin) or confirmatory criteria. Incubation is at 30 degrees C for 24-48 hrs. If a diagnosis is not possible than, a secondary series, including tests for lysine decarboxylase (tablets), 4 hr urease, esculin hydrolysis, growth at 42 C and on SS Agar, gelatin liquefaction, and flagellar staining may have to be used, and read after 4-24 hrs at 30 degrees C. Five tables, drawn up according to oxidase, glucose, and xylose reactions, serve to identify the species or taxa. Biotypes cannot be differentiated. The scheme will need updating as more knowledge of these bacteria will become available.
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PMID:[Culture and differentiation of obligatory aerobic gram-negative rods from human material; a scheme for application in routine diagnosis (author's transl)]. 101 32

Iron distribution in subcellular fractions was investigated at different times after a single cohort of 59Fe-125 I-labeled transferrin (Tf) endocytosis in K562 cells. Cell homogenates prepared by hypotonic lysis and deoxyribonuclease (DNAase) treatment were fractionated on Percoll density gradients. Iron-containing components in the postmitochondrial supernatant were further fractionated according to their molecular weight using gel chromatography and membrane filtration. In the initial phases of endocytosis, both iron and Tf were found in the light vesicular fraction. After 3 min the labels diverged, with iron appearing in the postmitochondrial supernatant and Tf in the heavy fraction containing mitochondria, lysosomes and nuclei. Iron released from Tf-containing vesicles appeared both in low- and high-molecular-weight fractions in the postmitochondrial supernatant. After 5 min of endocytosis 59Fe activity in the low-molecular-weight fraction remained constant and 59Fe accumulated in a high-molecular-weight fraction susceptible to desferrioxamine chelation. After 10 min, 59Fe radioactivity in this fraction decreased and a majority of cytosolic 59Fe was found in ferritin. These results do not support the concept of the cytosolic low-molecular-weight iron pool as a kinetic intermediate between transferrin and ferritin iron in K562 cells.
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PMID:Transferrin and iron distribution in subcellular fractions of K562 cells in the early stages of transferrin endocytosis. 142 Mar 21

Branhamella catarrhalis was formerly regarded as a common, essentially harmless inhabitant of the pharynx. This misapprehension was caused, in part, by confusion with another pharyngeal resident, Neisseria cinerea. The two organisms can now be differentiated by the positive reactions of B. catarrhalis in tests for nitrate reduction and hydrolysis of tributyrin and DNase. B. catarrhalis is currently recognized as the third most frequent cause of acute otitis media and acute sinusitis in young children. It often causes acute exacerbations of chronic bronchopulmonary disease in older or immunocompromised adults and is incriminated occasionally in meningitis, endocarditis, bacteremia, conjunctivitis, keratitis, and urogenital infections. Virulence-associated factors, such as pili, capsules, outer membrane vesicles, iron acquisition proteins, histamine-synthesizing ability, resistance to the bactericidal action of normal human serum, and binding to the C1q complement component, have been identified in some strains. beta-Lactamase producing strains, first detected in 1976, have risen to approximately 75% worldwide. Thus far, however, practically all American strains of B. catarrhalis remain susceptible to alternative antibiotics. A possible selective advantage of recent isolates is their reportedly heightened tendency for adherence to oropharyngeal cells from patients with chronic bronchopulmonary disease.
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PMID:Branhamella catarrhalis: an organism gaining respect as a pathogen. 212 28

A fraction extracted from BCG and designated MY-1, which was composed of 70.0% DNA and 28.0% RNA, was previously reported to possess strong antitumor activities against various syngeneic mouse and guinea pig tumors. An intraperitoneal injection of MY-1 (100 micrograms) 1 day before rendered mouse peritoneal cells cytotoxic to YAC-1 cells. The effector cells were nonadherent to plastic dishes, and the activity was destroyed by treatment with anti-asialo GM1 antiserum plus complement or carrageenan in vitro, but not with carbonyl-iron or anti-Thy 1.2, suggesting that the cells are natural killer (NK) cells. In vivo augmentation of NK activity was dependent on MY-1 dose, and reached the peak 1 day after MY-1 injection. Since NK activity in lipopolysaccharide (LPS)-nonresponder mice could be augmented by MY-1, the possibility that LPS contaminated the MY-1-augmented NK was excluded. MY-1 digested preliminarily with DNase lost its NK-inducing activity, suggesting that the DNA entity of MY-1 was essential for the activity. When mice were pretreated with anti-asialo GM1 or carrageenan, MY-1 could not render the peritoneal cells cytotoxic. Antitumor activities of MY-1 were also abolished if the animals were pretreated with anti-asialo GM1 antiserum or carrageenan, suggesting that the activities can be ascribed mainly to activated NK cells.
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PMID:In vivo augmentation of natural killer cell activity with a deoxyribonucleic acid fraction of BCG. 242 98

A series of metalloporphyrins linked through basic chains to certain DNA interactive groups has been synthesized. Several of these agents reproduce the characteristic properties of the antitumor glycopeptide bleomycin, including the oxygen-mediated scission of DNA in the presence of thiols, antibiobic activity under aerobic conditions, and activity against human and animal tumor models. Initial screening by scission of PM2-CCC-DNA identified six of the compounds, including those bearing acridine and acodazole intercalating groups, as the most active. The specificity of the oxygen-mediated scission of a 139 base pair HindIII/NciI restriction fragment of pBR322 by these six selected agents was then determined and compared with the action of pancreatic DNase by densitometric scans. All six of these compounds produce uniform base and sequence neutral cleavage of the restriction fragment at each base site. The six active compounds bear either of two types of intercalators, 6-chloro-2-methoxyacridine or acodazole, and with linkages to the ferric binding domain of -NH(CH2)2-, -NH(CH2)3-, -NH(CH2)4-, or -NH(CH2)3NH(CH2)3- and either porphyrin or deuteroporphyrin moieties. Comparison of the Kassoc values for binding to calf thymus DNA suggests that the enhanced binding observed with the linker -NH(CH2)3NH(CH2)3- contributes to the efficiency of sequence neutral DNA scission and may be a factor in the relative anticancer activities of these agents. The iron porphyrins give no evidence of the production of base propenals in DNA degradation, and the autoradiograms clearly indicate that a phosphate group is attached to the 5' end of the oligomer. The scission is partially suppressible by catalase and superoxide dismutase.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Deoxyribonucleic acid cleavage specificity of a series of acridine- and acodazole-iron porphyrins as functional bleomycin models. 242 95

A chemically defined medium (CDM) has been developed which supports both growth and hemolysin production by Haemophilus pleuropneumoniae. Although the growth rate in stationary cultures was substantially slower in CDM than in trypticase soy broth plus 0.6% yeast extract (TSBYE) and slightly slower than in heart infusion broth (HIB), extracellular hemolysin activity in CDM was slightly higher than in HIB and 16-fold greater than in TSBYE. Maximum hemolytic activity was produced in CDM in early to mid log phase of growth. Hemolytic activity in sterile, cell-free culture supernatant fluids persisted for over 10 days at 4 degrees C and 3-5 days at 37 degrees C, but was completely destroyed at 56 degrees C after 30 min. Total hemolysin inactivation was also achieved in the presence of trypsin or pronase (10 units/mL), but no decrease in hemolytic activity was noted in the presence of DNase or RNase. Iron had little effect on the hemolytic activity in the early stages of growth. However, in the later stages of growth, iron had a pronounced effect with hemolytic activity decreasing as the iron concentration increased from 1 to 500 microM. None of these iron concentrations had any effect on the hemolytic activity when added directly to prepared cell-free culture supernatant fluids. The extracellular hemolysin produced by H. pleuropneumoniae in CDM appears to be a heat-labile protein the activity of which is influenced by iron at certain phases of growth.
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PMID:Growth and hemolysin production by Haemophilus pleuropneumoniae cultivated in a chemically defined medium. 379 Oct 49


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