Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:1.11.1.6 (catalase)
 55,569 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Listeria monocytogenes, a gram-positive motile bacterium which can cause severe bacterial infection in humans, is considered to be pathogenic by virtue of its ability to resist intracellular killing. Since the mechanism of intracellular survival is poorly understood, we assessed the sensitivity of L. monocytogenes to several potent antibacterial products. Phorbol myristate acetate (PMA)-stimulated polymorphonuclear cells (PMNs) produced extracellular antibacterial products which were inhibited completely by catalase, suggesting a role for oxidative agents in this process. L. monocytogenes in logarithmic (log) growth phase resisted PMA-stimulated PMN extracellular products significantly more than L. monocytogenes in stationary (stat) growth phase or Escherichia coli (three strains) in either phase of growth. The role of oxidative agents was studied further by using xanthine oxidase-xanthine, glucose oxidase-glucose, and myeloperoxidase enzyme systems to generate hydroxyl radical (.OH), hydrogen peroxide (H2O2), and hypochlorous acid (OCl-), respectively. L. monocytogenes in log phase resisted the antibacterial products of these enzyme systems under conditions which produced superoxide (O2-) and H2O2 at concentrations similar to those produced extracellularly by PMA-stimulated PMNs, while stat-growth-phase L. monocytogenes and E. coli in either phase of growth were susceptible. Antibacterial activity could be blocked or inhibited by exogenous catalase (for all oxygen radical-generating systems), mannitol, or desferoxamine (for xanthine oxidase-xanthine) and alanine (for myeloperoxidase), suggesting that .OH and OCl- were responsible for this activity. Log-phase L. monocytogenes had 2.5-fold higher bacteria-associated catalase activity, as compared with stat-phase L. monocytogenes. These experiments, therefore, suggest that log-phase L. monocytogenes resists oxidative antibacterial agents by producing sufficient catalase to inactivate these products. This may contribute to the ability of L. monocytogenes to survive intracellularly.
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PMID:Relationship of bacterial growth phase to killing of Listeria monocytogenes by oxidative agents generated by neutrophils and enzyme systems. 282 83

Human peripheral blood monocytes (M), incubated with opsonized zymosan particles (OPZ), lysed human erythrocyte (RBC) targets, as detected by a 51Cr release method. Conversely, cells derived in vitro from M (monocyte-derived macrophages, MDM) were ineffective. When added to the M-RBC system, MDM enhanced the lysis. The lysis by M and M plus MDM was prevented by catalase, azide and amino acids (alanine, taurine), consistent with the requirement for hypochlorous acid (HOCl). Moreover, MDM per se incapable of generating HOCl augmented the HOCl recovery from the M-RBC system. The results provide evidence for a previously unrecognized form of interaction between two distinct populations of mononuclear phagocytes.
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PMID:Monocyte-derived macrophages as helper cells in monocyte-mediated cytolysis. 283 Aug 97

The erythrocyte (RBC) lysis by human monocytes incubated with opsonized zymosan particles (OPZ), was inhibited by catalase, chloride-free medium, azide and hypochlorous acid (HOCl) scavengers (taurine, alanine). These findings suggest the requirement for the HOCl-generating myeloperoxidase-hydrogen peroxide-chloride system (MPO-H2O2-Cl- system). The HOCl-dependent lysis was increased by inhibiting RBC catalase with aminotriazole (AT). Conversely, the inhibition of RBC glutathione cycle with 1,3-bis (2-chloroethyl)-1-nitrosourea (BCNU) had no detectable effect. Moreover, the recovery of H2O2 and HOCl from OPZ-triggered monocytes was reduced by the presence of RBCs through a process almost completely preventable by pulsing RBCs with AT but not with BCNU. Thus, it appears that RBC targets protect themselves by consuming, primarily via catalase, significant amounts of monocyte-derived H2O2 with a consequent impairment of the HOCl generation. The results suggest a potential role of target cells in modulating the cytolysin production by monocytes.
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PMID:Erythrocyte lysis by monocytes: investigations on the mechanism and role of the target cell hydrogen peroxide catabolizing pathways. 304 Oct 1

The effect of neutrophil migration and prolonged neutrophil contact on epithelial permeability was examined. Although neutrophil migration was not associated with a change in epithelial permeability, prolonged neutrophil-epithelial contact following migration resulted in an increase in epithelial permeability. These results were not altered by catalase, a specific neutrophil elastase inhibitor, methoxysuccinyl-Ala-Ala-Pro-Val-chloromethyl ketone or cyclohexamide. This suggests that neutrophil migration does not occur via an H2O2-induced reversible mechanism of junctional opening, which we describe herein.
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PMID:The effect of neutrophil migration and prolonged neutrophil contact on epithelial permeability. 331 30

Addition of glucose oxidase (GO) increased H2O2 concentrations and decreased antielastolytic activities of beta-D-glucose containing perfusates of isolated rat lungs. Pretreatment with GO also caused acute edematous injury (increased lung weight gains, increased recovery of Ficoll in lung lavages, and increased pulmonary arterial pressures) in isolated lungs perfused with purified human neutrophil elastase (NE). Acute edematous injury in isolated lungs pretreated with GO and then NE exceeded levels found in lungs following addition of GO or NE alone or NE before GO. Simultaneous addition of catalase (an H2O2 scavenger) or methoxy-succinyl-L-alanyl-L-alanyl-prolyl-L-valine-chloromethyl ketone (an NE inhibitor, but not aminotriazole-inactivated catalase, N-tosyl-L-phenyl-alanine chloromethyl ketone (a chymotrypsin inhibitor) or N-alpha-p-tosyl-L-lysine chloromethyl ketone (a trypsin inhibitor), prevented acute edematous injury in isolated lungs perfused with both GO and NE. This observation indicated that injury was dependent on both H2O2 and NE, especially since the relative inactivating specificities of the inhibitors for H2O2 or NE, respectively, were confirmed under similar conditions in vitro. The synergistic nature of the interaction between H2O2 and NE-mediated injury was further clarified when GO- and NE-induced lung injury was prevented by addition of an oxidant-resistant NE inhibitor (Eglin-C), but not an oxidant-sensitive NE inhibitor (human alpha 1-protease inhibitor, alpha 1PI). Moreover, treatment with H2O2 also decreased the ability of alpha 1PI but not Eglin-C to decrease NE activity in vitro.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:O2 metabolites and neutrophil elastase synergistically cause edematous injury in isolated rat lungs. 364 11

Neutrophils are thought to increase alveolar permeability in many types of lung injury. To investigate the contribution of neutrophils to the development of permeability pulmonary edema, we have developed an in vitro cell culture system for studying alveolar epithelial permeability. Rat alveolar type II cells, cultured for 6 to 12 days on collagen-coated Millipore filters, form a morphologically and pharmacologically polarized epithelium. The filters are mounted between 2 lucite chambers, and electrical resistance (permeability to ions) and spontaneous potential difference across the monolayer are measured continually or at frequent intervals. When neutrophils and the phagocytosable particle, opsonized zymosan (but not neutrophils or opsonized zymosan alone), were added to the apical side, the potential difference and transepithelial resistance fell dramatically after 20 min, which indicates an increase in epithelial permeability. The increase in epithelial permeability was inhibited by serum alpha-1-protease inhibitor (250 micrograms/ml), methoxysuccinyl-Ala-Ala-Pro-Val-chloromethyl ketone (0.02 mM) (an elastase inhibitor), catalase (2,500 units/ml), and superoxide dismutase (330 units/ml). In experiments with a lower concentration of phagocytosing neutrophils, a slower rate of decrease in resistance occurred, and in 3 of 13 studies, there was a definite recovery of the resistance to initial values. This study demonstrated that phagocytosing but not resting neutrophils increase the permeability of the epithelial monolayers to ions and suggests that the increased permeability in this system is mediated in part by both neutral protease(s) and oxygen radicals.
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PMID:Epithelial permeability produced by phagocytosing neutrophils in vitro. 370 98

Catalase is a tetrameric hemoprotein which degrades H2O2. Recombinant phage clones containing the human catalase gene have been isolated and characterized. The gene is 34 kb long and is split into 13 exons. The precise size and location of the exons has been determined. In addition, essentially full length catalase cDNA clones have been isolated and sequenced and used to tentatively identify the 5'-end of the gene. This assignment, if correct, predicts that the region upstream of the gene does not contain a TATA box. This region is GC rich (67%) and contains several CCAAT and GGGCGG sequences which may form part of the promoter. Translation of the catalase mRNA appears to begin immediately upstream of the amino-terminal Ala residue of catalase.
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PMID:Isolation and characterization of the human catalase gene. 375 25

As part of an investigation of the tRNA genes of Mycoplasma mycoides, two HindIII fragments of mycoplasma DNA comprising 0.4 and 2.5 kilobases (kb), respectively, were cloned in pBR322 and their nucleotide sequences determined. Only one tRNA gene was found in the 0.4 kb fragment, the gene for tRNAArg with the anticodon TCT, while the 2.5 kb fragment contained nine different tRNA genes arranged in a cluster which presumably constitutes a transcriptional unit. The clustered tRNA genes, with their respective anticodons, were as follows: Arg (ACG), Pro (TGG), Ala (TGC), Met (CAT), Ile (CAT), Ser (TGA), fMet (CAT), Asp (GTC), and Phe (GAA).
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PMID:Cloning and nucleotide sequence analysis of transfer RNA genes from Mycoplasma mycoides. 391 26

A cloned subline of the human monocytic leukemia cell line, THP-1, was induced to produce high levels of cytotoxic activity following an 18-hour phorbol myristate acetate (CAS: 16561-29-8) stimulation in vitro. This activity, termed monocyte cell line cytotoxin(s) (MCCT), was tested in vitro on different human continuous cell lines (Chang, ESH-7, GM3104A, HeLa, HT-1080, K562, Mel, T-24) and on primary human fibroblasts (GM3468, Manz). The continuous cell lines exhibited a spectrum of sensitivity to MCCT-containing supernatants whereas the primary fibroblasts were resistant to lysis. Enzymatic degradation and heat denaturation studies indicate that MCCT is a protein. Its bioactivity can be resolved into three lytic peaks after molecular sieving on Ultrogel AcA 44. The major peak, designated alpha MCCT, eluted with a molecular weight of 100,000-140,000 daltons. A minor peak, beta MCCT, was seen at 60,000-80,000 daltons, and a third, unstable minor peak, gamma MCCT, eluted at less than 10,000 daltons. The alpha-lytic peak was examined further and was found to migrate as a single peak in 7% native polyacrylamide gel electrolysis tube gels with an rf of 0.25-0.30. None of the MCCT forms were immunologically cross-reactive with human alpha-lymphotoxin. Various protease inhibitors known to inhibit monokine- and macrophage-mediated direct cell lysis in vitro were tested for their inhibitory effects on alpha MCCT activity. The irreversible binding inhibitor N alpha-p-tosyl-L-lysyl chloromethyl ketone inhibited the biologic activity of alpha MCCT. The reversible binding inhibitors N alpha-p-tosyl-L-arginine methyl ester and soybean trypsin inhibitor were able to block in vitro lytic activity when added to alpha MCCT in the presence of the target cell. In contrast, the inhibitors phenylmethylsulfonyl fluoride, L-1-tosylamide, 2-phenylethyl chloromethyl ketone, and N alpha-acetyl-L-lysine methyl ester were not effective in blocking cytolysis. Finally, the hydrogen peroxide scavenger catalase inhibited alpha MCCT lytic activity in vitro; however, the hypochlorous acid scavengers alanine, serine, and valine were without effect.
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PMID:Isolation and initial characterization of tumoricidal monokine(s) from the human monocytic leukemia cell line THP-1. 391 10

The conversion of tyrosine into dopa [3-(3,4-dihydroxyphenyl)alanine] is the rate limiting step in the biosynthesis of melanins catalysed by tyrosinase. This hydroxylation reaction is characterized by a lag period, the extent of which depends on various parameters, notably the presence of a suitable hydrogen donor such as dopa or tetrahydropterin. We have now found that catalytic amounts of Fe2+ ions have the same effect as dopa in stimulating the tyrosine hydroxylase activity of the enzyme. Kinetic experiments showed that the shortening of the induction time depends on the concentration of the added metal and the nature of the buffer system used and is not suppressed by superoxide dismutase, catalase, formate or mannitol. Notably, Fe3+ ions showed only a small delaying effect on tyrosinase activity. Among the other metals which were tested, Zn2+, Co2+, Cd2+ and Ni2+ had no detectable influence, whereas Cu2+ and Mn2+ exhibited a marked inhibitory effect on the kinetics of tyrosine oxidation. These findings are discussed in the light of the commonly accepted mechanism of action of tyrosinase.
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PMID:Effect of metal ions on the kinetics of tyrosine oxidation catalysed by tyrosinase. 392 96


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