Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:P04040 (Catalase)
 3,577 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Temporal aspects of the effects of inhibitors on hepatic cytochrome P-450 destruction and lipid peroxidation induced by NADPH and linoleic acid hydroperoxide (LAHP) were compared. In the absence of added Fe2+, NADPH-induced lipid peroxidation in hepatic microsomes exhibited a slow phase followed by a fast phase. The addition of Fe2+ eliminated the slow phase, thus demonstrating that iron is a rate-limiting component in the reaction. EDTA, which complexes iron, and p-chloromercurobenzoate (pCMB), which inhibits NADPH-cytochrome P-450 reductase, inhibited both phases of the reaction. Catalase as well as scavengers of hydroxyl radical, inhibited NADPH-induced lipid peroxidation almost completely. GSH also inhibited the NADPH-dependent reaction but only when added at the beginning of the reaction. In contrast with NADPH-dependent lipid peroxidation, the autocatalytic reaction induced by LAHP was not biphasic, NADPH-dependent or iron-dependent, nor was it inhibited by hydroxyl radical scavengers, catalase or GSH. A synergistic effect on lipid peroxidation was observed when both NADPH and LAHP were added to microsomes. It is concluded that both the fast and slow phases of NADPH-dependent microsomal lipid peroxidation are catalyzed enzymatically and are dependent upon Fe2+, whereas LAHP-dependent lipid peroxidation is autocatalytic. Since the fast phase of enzymatic lipid peroxidation occurred during the fast phase of destruction of cytochrome P-450, it is postulated that iron made available from cytochrome P-450 is sufficient to promote optimal lipid peroxidation. Since catalase and hydroxyl radical scavengers inhibited NADPH-dependent but not LAHP-dependent lipid peroxidation, it is concluded that the hydroxyl radical derived from H2O2 is the initiating active-oxygen species in the enzymatic reaction but not in the autocatalytic reaction.
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PMID:NADPH- and linoleic acid hydroperoxide-induced lipid peroxidation and destruction of cytochrome P-450 in hepatic microsomes. 357 83

Catalase and superoxide dismutase detected in both RH and C strain Toxoplasma gondii tachyzoites were distinctly different in electrophoretic mobility from host cell enzymes. Catalase and superoxide dismutase activity levels were similar in both Toxoplasma strains and showed narrow pH optima around 8.0. Toxoplasma superoxide dismutase was resistant to cyanide but inhibited by azide or peroxide, consistent with an iron-containing enzyme typical of protozoan parasites. These enzymes may play a role in intracellular survival; however, they do not appear to be the basis for differences in virulence to mice.
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PMID:Superoxide dismutase and catalase in Toxoplasma gondii. 371 45

The ability to grow a clone of the cell line, MLA144, which is a constitutive producer of interleukin 2 (IL-2), in serum-free medium permitted the study of the direct effect of various agents on cell growth and IL-2 production in a homogeneous population. Bovine serum albumin (BSA) at 4 mg/ml was optimal for cell growth and IL-2 production. Selenium at 10 ng/ml enhanced IL-2 production nearly twofold and lithium at 42 ng/ml also enhanced IL-2 production by nearly twofold. Neither compound at these levels altered cellular proliferation. Two other compounds, iron and zinc, known to be associated with cellular proliferation and/or immunoregulation did not alter IL-2 production. Catalase or horseradish peroxidase was able to substitute for BSA and maintain the long-term growth of the MLA144 clone with only a 30% decrease in the rate of cellular proliferation and a 50% decrease in IL-2 production compared to cells maintained in the serum-free formulation with BSA. Addition of 0.5 mg of BSA to the catalase serum-free formulation increased the production of IL-2 to 70% of that of cells cultured in the BSA-containing serum-free formulation. The catalase-containing serum-free formulation has the advantage of consisting of only three proteins, catalase, insulin, and transferrin, at a very low protein content. The catalase-containing serum-free medium also supported the long-term growth of a human T-cell line, HSB-2.
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PMID:Modulation of interleukin 2 release from a primate lymphoid cell line in serum-free and serum-containing media. 393 31

We evaluated whether supplemental pharmacologic interventions that altered formation or degradation of reactive oxygen metabolites, when added to hypothermic crystalloid cardioplegic solution (procaine-free St. Thomas' Hospital solution), alter postischemic function of isolated rabbit hearts. Hypoxic, substrate-free cardioplegic solutions cooled to 27 degrees C were perfused through isolated rabbit hearts for 5 minutes before and after an uninterrupted 2 hour period of global ischemia at 27 degrees C. Hearts were then reperfused with standard buffer for 1 hour at 37 degrees C. In some experiments, the cardioplegic solution was supplemented with the following: superoxide dismutase (30 micrograms/ml; degrades superoxide anion); catalase (1.7 micrograms/ml; degrades hydrogen peroxide); allopurinol (1 mmol/L; inhibits xanthine oxidase); or deferoxamine (Desferal, 0.5 mmol/L; selectively chelates ferric iron). Postreperfusion contractile parameters of supplemented hearts, including left ventricular pressure development and its first derivative, left ventricular compliance, spontaneous heart rate, and coronary vascular resistance, were statistically compared to data obtained from hearts arrested with unsupplemented cardioplegic solution. Catalase supplementation provided statistically significant improvement of most functional parameters; somewhat less protection was obtained with allopurinol. Deferoxamine provided little added protection except for the ability to prevent ischemia-induced increases of coronary vascular resistance. There was no evidence of added protection by superoxide dismutase. The data suggest that an important component of ischemia-induced cardiac cell damage in an asanguineous setting is hydrogen peroxide-dependent, and interventions that either inhibit production of superoxide anion or degrade hydrogen peroxide offer best protection. They may be clinically efficacious additives to crystalloid cardioplegic solutions.
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PMID:Effects of supplementing hypothermic crystalloid cardioplegic solution with catalase, superoxide dismutase, allopurinol, or deferoxamine on functional recovery of globally ischemic and reperfused isolated hearts. 394 95

Phenylalanine hydroxylase was prepared from rat liver and purified 200-fold to about 90% purity. All the enzymic activity of the liver appeared in a single protein of mol.wt. approx. 110000, but omission of dithiothreitol and of a preliminary filtration step to remove lipids resulted in partial conversion into a second enzymically active protein of mol.wt. approx. 250000. The K(m) and V(max.) values of the enzyme for phenylalanine, p-fluorophenylalanine and dimethyltetrahydropterin were measured; p-chlorophenylalanine inhibited the enzyme by competing with phenylalanine. Disc gel electrophoresis at pH7.2 showed a single protein band containing all the enzymic activity, but at pH8.7 the enzyme dissociated into two inactive fragments of similar but not identical molecular weight. The molecule of phenylalanine hydroxylase contained two atoms of iron, one atom of copper and one molecule of FAD; molybdenum was absent. Treatment with chelating agents showed that both non-haem iron and copper were necessary for enzymic activity. The molecule contained five thiol groups, and thiol-binding reagents inhibited the enzyme. Catalase or peroxidase enhanced enzymic activity fivefold; it is postulated that catalase (or other peroxidase) plays a part in the hydroxylation reaction independent of the protection by catalase of enzyme and cofactor from inactivation by a hydroperoxide.
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PMID:The isolation and properties of phenylalanine hydroxylase from rat liver. 485 20

Campbell, Jack E. (University of California, Berkeley), and R. L. Dimmick. Effect of 3% hydrogen peroxide on the viability of Serratia marcescens. J. Bacteriol. 91:925-929. 1966.-Populations of Serratia marcescens were exposed to 3% H(2)O(2) at temperatures from 0 to 20 C. The reaction appeared to follow an Arrhenius plot, but variable numbers of diminutive colonies were found after cell numbers started to decrease. Colony numbers varied on different sampling media and increased when additional incubation was imposed. The overall reaction was sensitive to age of culture, and growth capabilities of treated samples varied with time of treatment, especially during times when no loss of viability was noted. Catalase activity per cell did not correlate with changes in sensitivity; iron added to growth medium increased catalase activity and decreased sensitivity, but not in the same manner. Although the fundamental reaction is presumably molecular in nature, present methods of viability assay measure more than single events and are not suitable for these studies.
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PMID:Effect of 3 percent hydrogen peroxide on the viability of Serratia marcescens. 532 3

The mechanism of activation of soluble guanylate cyclase purified from bovine lung by phenylhydrazine is reported. Heme-deficient and heme-containing forms of guanylate cyclase were studied. Heme-deficient enzyme was activated 10-fold by NO but was not activated by phenylhydrazine. Catalase or methemoglobin enabled phenylhydrazine to activate guanylate cyclase 10-fold and enhanced activation by NO to over 100-fold. Heme-containing enzyme was activated only 3-fold by phenylhydrazine but over 100-fold by NO. Added hemoproteins enhanced enzyme activation by phenylhydrazine to 12-fold without enhancing activation by NO. Reducing or anaerobic conditions inhibited, whereas oxidants enhanced enzyme activation by phenylhydrazine plus catalase, and KCN had no effect. In contrast, enzyme activation by NO and NaN3 was inhibited by oxidants or KCN. NaN3 required native catalase, whereas phenylhydrazine also utilized heat-denatured catalase for enzyme activation. Thus, the mechanism of guanylate cyclase activation by phenylhydrazine differed from that by NO or NaN3. Guanylate cyclase activation by phenylhydrazine resulted from an O2-dependent reaction between phenylhydrazine and hemoproteins to generate stable iron-phenyl hemoprotein complexes. These complexes activated guanylate cyclase in the absence of O2, but lost activity after acidification, basification, or heating. Gel filtration of prereacted mixtures of [U-14C]phenylhydrazine plus hemoproteins resulted in co-chromatography of radioactivity, protein, and guanylate cyclase stimulating activity, and yielded a phenyl-hemoprotein binding stoichiometry of four under specified conditions (one phenyl/heme). [14C]Phenyl bound to heme-containing but not heme-deficient guanylate cyclase and binding correlated with enzyme activation. Moreover, reactions between enzyme and iron-[14C] phenyl hemoprotein complexes resulted in the exchange or transfer of iron-phenyl heme to guanylate cyclase and this correlated with enzyme activation.
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PMID:Guanylate cyclase from bovine lung. Evidence that enzyme activation by phenylhydrazine is mediated by iron-phenyl hemoprotein complexes. 614 58

Recently, some knowledge of metabolic pathways, rather than individual enzyme activities of M. leprae, is becoming available. Ultimately this may be useful in devising culture media for M. leprae. Knowledge restricted to individual reactions may be misleading. For instance, the detection of GlcNacase and beta-glucuronidase and the subcellular localization of hyaluronic acid led to attempts to cultivate M. leprae on hyaluronic-acid based medium. Subsequent investigations suggested that there was no pathway for the breakdown of hyaluronic acid in M. leprae. The biochemical pathways for breaking down glucose and glycerol seem to be complete, and thus similar to many bacteria, but there is an unusually high level of one enzyme, 6-phosphogluconate dehydrogenase (6PGDH). Although 6-phosphogluconate is oxidized by M. leprae, and this is an unusual activity, reflecting very high levels of 6PGDH, glycerol may be a preferable energy source (on the basis of rates of oxidation by suspensions) for M. leprae in attempts to cultivate the bacterium. The utilization of 6-phosphogluconate might be important for other aspects of M. leprae metabolism not yet investigated (e.g., pentose metabolism) or it may be an adaption, not needed in vitro, to its existence in host macrophages. Alternatively, its oxidation may be a way of rapidly generating NADPH at critical times for the bacterium. Other unusual activities which have been reported are the presence of an enzyme characteristic of chemoautotrophism , completely surprising in view of the biology of M. leprae. This report needs to be confirmed--some aspects, in fact, have failed to be confirmed. o-Diphenoloxidase activity is unique, among mycobacteria, to M. leprae, but there is still doubt over whether or not it is an enzymatic activity and its function is unknown. A transpeptidase which may be involved in cell wall synthesis, recently demonstrated in M. leprae, is a typical mycobacterial enzyme. It is now known that iron could be supplied to M. leprae in potential media in the form of ferriexochelin from M. neoaurum . Two "deletions" in the metabolic processes of M. leprae have been observed. Catalase appears to be absent in M. leprae; its addition to media stimulates the growth of some organisms since peroxides form in the bacteriological media . Purine synthesis de novo occurred at a very low rate compared with purine scavenging. Whether this is an adaption to growth in vivo is not known.(ABSTRACT TRUNCATED AT 400 WORDS)
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PMID:Metabolism in Mycobacterium leprae: its relation to other research on M. leprae and to aspects of metabolism in other mycobacteria and intracellular parasites. 614 38

The enhancing effect of haem compounds on the growth of Escherichia coli, Staphylococcus aureus and Streptococcus agalactiae in whey cultures was studied turbidometrically. Catalase, myoglobin and haemoglobin in concentrations 10(-5) to 10(-3) M enhanced bacterial growth. One explanation of this was the availability of iron by these haem compounds for the bacteria. However, evidence from experiments on free radical generating systems by t-BHP and hydrogen peroxide indicated that haem compounds scavenge activated oxygen products and so protect bacteria from oxygen toxicity.
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PMID:Haem compounds as bacterial growth promoters in whey: a possible application to bovine mastitis. 632 10

During inflammation, the superoxide anion (O-2) and hydrogen peroxide (H2O2) are produced by stimulated polymorphonuclear leukocytes and macrophages. The toxic effects of these reactive oxygen intermediates increase when traces of iron are present, because iron catalyzes the formation of the hydroxyl radical (OH.). Partially saturated iron-binding proteins, such as transferrin and ferritin, are unable to catalyze OH. formation in vitro. Mobilization of iron from these proteins is necessary for iron stimulation of OH. formation. This paper reports that stimulated polymorphonuclear leukocytes mobilize iron from human and horse ferritin, but not from human transferrin. Iron release from ferritin depends on O-2 because it can be prevented by the addition of superoxide dismutase. Catalase and dimethylsulfoxide have no inhibitory effect on iron mobilization. The efficiency of the iron release increases at low levels of O-2 production. Only O-2 produced by granulocytes is sufficient for iron mobilization, because solid potassium superoxide is also able to release iron from ferritin. We propose that this reaction may potentiate the formation of the OH. radical in inflammatory states.
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PMID:Iron mobilization from ferritin by superoxide derived from stimulated polymorphonuclear leukocytes. Possible mechanism in inflammation diseases. 632 64


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