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)

Macrolide is inactivated with ATP plus crude extract of Escherichia coli producing macrolide 2'-phosphotransferase (MPH(2')), but not by living cells. Therefore, a convenient method for detection of MPH(2') using intact cells is needed. In this report, we determine that the modified lysozyme-DNase-RNase (LDR) method (named ELDR method) is at least one hundred times more sensitive for the detection of MPH(2') activity than the LDR method and, in addition, highly sensitive for the detection of aminoglycoside-modifying enzymes. Therefore, three new MPH(2')-producing strains were found in clinically isolated E. coli in Japan in 1997 by this method. It suggests that MPH(2')-producing E. coli have been spread in Japanese clinical fields.
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PMID:Identification of Escherichia coli clinical isolates producing macrolide 2'-phosphotransferase by a highly sensitive detection method. 980 20

An in situ reverse transcription-PCR protocol for detecting specific mRNA in Methanosarcina mazei S-6 is described. This method allowed us to detect heat shock-induced increases in the intracellular levels of the transcript of the universal stress gene dnaK. The cell walls of paraformaldehyde-fixed cells were permeabilized by a thermal cycling procedure or by lysozyme treatment, and the cellular DNA was removed with DNase. The cells were subjected to a seminested reverse transcription-PCR protocol in which a digoxigenin-labeled primer was used. Detection of the reporter molecule was based on the 2-hydroxy-3-naphtoic acid-2'-phenylanilide phosphate-Fast Red detection system and binding of anti-digoxigenin-alkaline phosphatase conjugate. Fluorescence in permeabilized cells increased after a heat shock compared to fluorescence in non-heat-shocked cells, and the increase corresponded to an increase in the level of the dnaK transcript.
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PMID:In situ reverse transcription-PCR for monitoring gene expression in individual Methanosarcina mazei S-6 cells. 1078 41

The complex clinico-laboratory examination of 92 children aged 3-14 years with the localized form of stomatopharyngeal diphtheria and toxigenic C. diphtheriae (TCD) carrier state was carried out. The children were hospitalized in the clinic of drop infections during the period of 1996-1998. The hydrophobic properties, adhesive, lysozyme, antilysozyme and DNAase activities of 92 TCD strains, as well as the levels of the specific and nonspecific immunity of the macroorganism, were studied. The study revealed that the character of the infectious process in TCD carrier state was determined by the degree of the colonization activity of the infective agent. Direct correlation between the time of the persistence of TCD in the body and their hydrophobic properties, adhesive and antilysozyme activities (with r = 0.89-0.93) was established. The duration of TCD carrier state was found to be inversely related to the electrophysiological state of epithelial cells of the mucosa, the level of humoral specific antibacterial immunity and the content of local antidiphtheria IgA.
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PMID:[Adaptation mechanisms in the formation of the Corynebacterium diphtheriae carrier state]. 1271 9

A method has been described for isolation of the specific cytoplasmic granules of rabbit polymorphonuclear leucocytes. Homogeneous suspensions of leucocytes were disrupted by lysis in 0.34 M sucrose. This procedure liberated the cytoplasmic contents of the cell and dissolved a considerable proportion of the nuclei. Following disruption, the sucrose lysate was separated into three fractions by differential centrifugation, i.e. 400 g or nuclear pellet, 8,200 g or granule pellet and the postgranule supernate. Microscopic examination revealed that the 8,200 g pellet was composed of intact granules as well as occasional mitochondria. The other two fractions were morphologically heterogeneous. Studies with isolated granules demonstrated their lysis by a variety of weak acids and surface-active agents. When buffered solutions were employed between the ranges of pH 2.0 and 9.0, granule lysis began at pH 5.5 and was complete at pH 4.0. Chemical analysis disclosed that the granule pellet contained protein and phospholipid with only traces of nucleic acids. Approximately 70 to 80 per cent of the total cellular antimicrobial agent phagocytin was present in the granule fraction. This material was liberated from the granules by acid (pH 5.0 or lower). Studies on selected enzymes showed that acid phosphatase, alkaline phosphatase, nucleotidase, ribonuclease, deoxyribonuclease, and beta glucuronidase were predominantly localized in the granule fraction. Approximately 50 per cent of total cellular lysozyme and cathepsin were also present in the 8,200 g pellet. Disruption of the granules was associated with the release of the majority of granule protein and enzymes in a non-sedimentable form. The properties and composition of rabbit polymorphonuclear leucocyte granules seem to be analogous to those of liver lysosomes.
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PMID:The isolation and properties of the specific cytoplasmic granules of rabbit polymorphonuclear leucocytes. 1369 90

Schlessinger, David (Washington University School of Medicine, St. Louis, Mo.), Vincent T. Marchesi, and Benjamin C. K. Kwan. Binding of ribosomes to cytoplasmic reticulum of Bacillus megaterium. J. Bacteriol. 90:456-466. 1965.-As many as 60% of the cellular ribosomes are bound to membrane "ghosts" in lysozyme lysates in 0.02 m Mg(2+). Bound ribosomes labeled with C(14)-uracil do not exchange with added unlabeled ribosomes, even after disruption of the cell membrane by sonic treatment. Electron micrographs of thin sections of ghosts, or of fragments produced by sonic disruption of protoplasts, indicate that the ribosomes are distributed on a reticular matrix which extends throughout the cytoplasm. The binding of ribosomes to this matrix is insensitive to ribonuclease or deoxyribonuclease, and has many other features in common with the binding of ribonucleoprotein to the membranous elements of the mammalian microsomal fraction, though the reticulum does not appear to be membranous. Thus, functioning ribosomes may be bound to a cytoplasmic structure in all cell types.
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PMID:BINDING OF RIBOSOMES TO CYTOPLASMIC RETICULUM OF BACILLUS MEGATERIUM. 1432 62

The proper function of the genome largely depends on the higher-order architecture of the chromosome. To understand the detailed chromosome structure in a native state, we developed an on-substrate procedure of subcellular fractionation suitable for the observation by atomic force microscopy (AFM). HeLa cells on a coverslip were successively treated with a detergent and a high-salt solution to remove the cytoplasmic and nucleoplasmic materials. A closer observation of the nucleus by AFM revealed that the interphase chromosome is composed of a granular unit of approximately 80 nm in diameter. Subsequent mild treatment with deoxyribonuclease I (10 U ml(-1)) exposed these units more clearly, which enabled us to uncover the 80-nm granules forming a fibre of approximately 80 nm width. In the cytoplasmic regions, cytoskeletal fibres with varying widths (10-70 nm) were observed. These observations suggest that the 80 nm granular fibre is a fundamental structural unit of the interphase chromosome. This on-substrate procedure was also applied to Escherichia coli. Cells attached on a coverslip were successively treated with lysozyme and detergent to partially release the nucleoid onto the substrate. The AFM observation revealed that the approximately 80 nm fundamental structural unit forms a granular fibre similar to that of HeLa cells. These results suggest that the fundamental mechanism of chromosome packing is common in both prokaryotes and eukaryotes.
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PMID:On-substrate lysis treatment combined with scanning probe microscopy revealed chromosome structures in eukaryotes and prokaryotes. 1459 4

The release of chromosomal DNA into culture media has been reported for several naturally transformable bacterial species, but a direct link between competence development and the liberation of DNA is generally lacking. Based on the analysis of strains with mutations in competence-regulatory genes and the use of conditions favouring or preventing competence, we provide evidence that DNA release is triggered by the induction of competence in Streptococcus pneumoniae. Kinetic analyses revealed that whereas competence was maximal 20 min after addition of competence-stimulating peptide, and then decreased, the amount of liberated DNA continued to increase and reached a maximum in stationary phase, when cells are no longer competent for DNA uptake. These data are not consistent with the proposal that release of DNA by a fraction of the population is coordinated with uptake by the remainder. Moreover, we observed that an unidentified DNase was specifically induced or released in competent cultures, and that together with the major pneumococcal endonuclease, EndA, it could degrade released DNA. Nearby complete abolition of release in a mutant lacking both the major autolysin, LytA, and the autolytic lysozyme, LytC, indicated that DNA liberation occurs by LytA-LytC-dependent cell lysis. These observations suggest that competence-dependent DNA release is one facet of a more general phenomenon of sensitization to autolysis that reaches its maximum in stationary phase.
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PMID:Release of DNA into the medium by competent Streptococcus pneumoniae: kinetics, mechanism and stability of the liberated DNA. 1549 67

Syringacin 4-A, a bacteriocin produced by Pseudomonas syrinagae 4-A, was obtained by induction with ultraviolet irradiation or mitomycin C. Approximately 1,000-fold purification of the bacteriocin was achieved by manganous chloride precipitation, differential centrifugation, and chromatography on hydroxyapatite columns. The purified syngacin was homogeneous on hydroxyapatite columns and sucrose density gradients; it also sedimented as a single entity in the analytical ultracentrifuge. The buoyant density of purified syringacin in cesium chloride was 1.294 g/ml. The sedimentation coefficient was calculated as 120S, and the diffusion coefficient was 6.49 x 10(-8) cm(2)/s. The molecular weight was calculated as 1.6 x 10(7) from physical data and 1.7 x 10(7) from biological data. The syringacin was composed of about 88.4% protein, 8.5% arabinose, 2.2% galacturonic acid, and 0.7% glucosamine. Amino acid analysis indicated a predominance of leucine (12.1%), aspartic acid (12.2%), and glutamic acid (12.7%). The ultraviolet spectrum showed a maximum absorbance peak at 276 nm. The syringacin was heat and alcohol sensitive, but resistant to trypsin, chymotrypsin, carboxypeptidase, Pronase, protease, lysozyme, steapsin, deoxyribonuclease, and ribonuclease. Maximum pH stability was between 5 and 8. Crude bacteriocin was stable at room temperature for at least a year, and purified material was stable for at least 3 months at 4 C.
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PMID:Purification and characterization of syringacin 4-A, a bacteriocin from pseudomonas syringae 4-A. 1582 74

Bundles of F-actin and DNA present in the sputum of cystic fibrosis (CF) patients but absent from normal airway fluid contribute to the altered viscoelastic properties of sputum that inhibit clearance of infected airway fluid and exacerbate the pathology of CF. Previous strategies to remove these filamentous aggregates have focused on DNase to enzymatically depolymerize DNA to constituent monomers and gelsolin to sever F-actin to small fragments. The high densities of negative surface charge on DNA and F-actin suggest that the bundles of these filaments, which alone exhibit a strong electrostatic repulsion, may be stabilized by multivalent cations such as histones, antimicrobial peptides, and other positively charged molecules prevalent in airway fluid. This study reports that bundles of DNA or F-actin formed after addition of histone H1 or lysozyme are efficiently dissolved by soluble multivalent anions such as polymeric aspartate or glutamate. Addition of poly-aspartate or poly-glutamate also disperses DNA and actin-containing bundles in CF sputum and lowers the elastic moduli of these samples to levels comparable to those obtained after treatment with DNase I or gelsolin. Addition of poly-aspartic acid also increased DNase activity when added to samples containing DNA bundles formed with histone H1. When added to CF sputum, poly-aspartic acid significantly reduced the growth of bacteria, suggesting activation of endogenous antibacterial factors. These findings suggest that soluble multivalent anions have potential alone or in combination with other mucolytic agents to selectively dissociate the large bundles of charged biopolymers that form in CF sputum.
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PMID:Anionic poly(amino acid)s dissolve F-actin and DNA bundles, enhance DNase activity, and reduce the viscosity of cystic fibrosis sputum. 1596 1

Some properties of the cell-free and cell-associated hemolysins of Escherichia coli were studied. Several strains of E. coli that were isolated from intestines of pigs with edema disease produce large quantities of cell-free hemolysin when grown in the presence of an extract of meat. The component of meat that stimulates production of cell-free hemolysin is not extracted by lipid solvents and is not dialyzable. The cell-free hemolysin is an acidic substance that occurs in two forms. It is inactivated by trypsin but not by lecithinase, lysozyme, ribonuclease, or deoxyribonuclease, shows optimum activity between pH 7 and 8, and requires calcium ion for activity. It does not appear to be an enzyme. The kinetics of the lytic reaction are most consistent with the hypothesis that one molecule of cell-free hemolysin is sufficient to lyse one erythrocyte and that it is inactivated in the lytic reaction. The cell-free hemolysin does not sufficiently damage the cell during the prelytic period to cause lysis after the hemolysin-calcium-erythrocyte complex has been disrupted. The cell-associated hemolysin was not separated from the cell by autolysis, freezing, sonic treatment, or treatment with trypsin or lysozyme. It appears to be closely associated with the metabolic status of the cell. Organisms that are highly hemolytic under usual conditions of assay immediately lose most of their hemolytic capability in the presence of sodium cyanide, streptomycin, nalidixic acid, and rifampin.
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PMID:Properties of the Hemolytic Activities of Escherichia coli. 1655 36


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