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)

Changes in the membranes of human red cells similar to those of certain hemolytic anemias were produced by calcium in three model systems and found to result from membrane adsorption of cytosol proteins and from proteolysis. Proteins of the cytosol adsorbed to human erythrocyte membranes in the presence of calcium and extractable by EDTA were compared to those of the total cytosol by polyacrylamide gel electrophoresis and by isoelectric focusing. Catalase (EC 1.11.1.6) and band 8 were adsorbed to the membranes from the supernatant cytosol with calcium. Band 8 was a normal constitutent of the cytosol, apparently a single chain of molecular weight 24,000 with a pI of 5.35. Other calcium-induced membrane changes could be demonstrated to be due to cytosol protease(s) adsorbed to the membrane in the presence of calcium and extractable with EDTA. When membranes were incubated with the proteases and calcium the decrease in bands 1,2,3 and 4.1 and the appearance of multiple low molecular weight peptides typical of calcium-induced membrane effects resulted.
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PMID:Calcium-induced erythrocyte membrane changes. The role of adsorption of cytosol proteins and proteases. 42 45

1. Cytosolic calcium concentrations ([Ca2+]i) were determined with fura-2 on both resting (unstimulated) and A23187-stimulated coronary endothelial cells following injury by hydrogen peroxide (H2O2). 2. Treatment of cells with H2O2 (10(-4) M) caused an increase in the resting [Ca2+]i, which reached a maximum of five fold after 3 h. 3. The increase in resting [Ca2+]i was significantly attenuated by treatment with U78517F, a potent inhibitor of lipid peroxidation, at a concentration of 10(-6) M or greater. Catalase (50 u ml-1) also markedly inhibited the H2O2-induced rise in [Ca2+]i. Pretreatment with verapamil (10(-5) M), nifedipine (10(-6) M) or diltiazem (10(-5) M) had no effect on the increase in [Ca2+]i following addition of H2O2. 4. A23187 produced a transient increase in [Ca2+]i followed by a sustained plateau. The initial peak and plateau phase responses to A23187 were augmented by H2O2. This augmentation of [Ca2+]i was suppressed by U78517F or catalase but not by Ca-entry blockers. 5. Thus, it is likely that lipid peroxidation plays a critical role in the sustained increase in [Ca2+]i that occurs following treatment with H2O2 and that this continues in the presence of agonists which stimulate the endothelium. Voltage-gated Ca2+ channels do not seem to be involved in the genesis of cellular damage associated with sustained large increases in [Ca2+]i.
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PMID:Cytosolic calcium increase in coronary endothelial cells after H2O2 exposure and the inhibitory effect of U78517F. 142 94

Human blood platelets produce oxidant species when stimulated by collagen and thrombin. The oxidative burst of platelets has been studied by cytofluorimetry taking advantage of the fluorogenic dye DCFH2-DA, which is taken up and deacetylated by platelets and then oxidized to the fluorescent derivative DCF. The oxidation of DCFH2 is induced by stimulation with collagen but not with thrombin and inhibited by external catalase. Catalase also inhibited the aggregation induced by collagen, but not that induced by thrombin. Aspirin and indomethacin inhibited the formation of the fluorochrome only when platelets were stimulated by thrombin. Externally added H2O2 increased the cytoplasmic calcium content as probed by the fluorescence of Indo-1. The present data suggest that collagen induces the production of H2O2, which in turn may stimulate the aggregation of platelets through a calcium mobilization. Instead the stimulation by thrombin does not require the intermediacy of H2O2.
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PMID:Hydrogen peroxide is an intermediate in the platelet activation cascade triggered by collagen, but not by thrombin. 189 57

A procedure was developed for the per cell estimation of catalase activities in suspensions and cultures of murine epidermal keratinocytes (MEKs). Per cell catalase activity in MEKs cultured in low Ca2+ medium was relatively constant during the proliferation phase of culturing, but increased approximately 100% within 24 h of cessation of cell division. 12-O-Tetradecanoylphorbol-13-acetate (TPA) treatment of proliferating MEKs cultured in low Ca2+ medium resulted in (i) an initial suppression of proliferation, (ii) the accelerated detachment and differentiation of detached MEKs and (iii) a suppression of catalase induction in the detached population. Induction of MEK differentiation by raising the medium Ca2+ concentration resulted in rapid inhibition of cell division and approximately 200% increases in per cell catalase activities. Addition of TPA immediately prior to Ca2+ shift completely suppressed the Ca2(+)-dependent increases in activity. However, the addition of TPA 48 h after the induction of differentiation by Ca2+ shift had no effects on the elevated, pre-existing catalase activities. Per cell catalase activities varied in vivo with the stage of MEK differentiation. Specifically, the lowest and highest per cell activities (approximately 4-fold difference) were measured in enriched basal cell and spinous cell populations respectively. Catalase activity in the more differentiated MEKs was reduced approximately 33% within 24 h of topical treatment of dorsal skin with a promoting dose of TPA. However, catalase activity in enriched basal cell preparations was unaffected. Collectively, these studies demonstrate that per cell catalase activities increase as MEKs differentiate, and that TPA suppresses the increases in catalase activities that normally occur during differentiation.
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PMID:Modulation of catalase activities in murine epidermal cells as a function of differentiation and exposure to 12-O-tetradecanoylphorbol-13-acetate. 234 71

Superoxide radicals inactivate endoplasmic reticular (ER) Ca2+ pump in membranes isolated from smooth muscle of pig right coronary artery [Am. J. Physiol. 255 (Cell Physiol. 24): C297-C303, 1988]. We report on protective mechanisms against such inactivation. This tissue contained superoxide dismutase (SOD) and catalase. SOD was distributed primarily in cytosolic fraction, was cyanide sensitive, and was also present in mitochondrial fraction, and approximately 25% of this was cyanide insensitive. Catalase was distributed mainly in mitochondrial fraction and did not protect against inactivation of ER Ca2+ pump by superoxide radicals generated using xanthine plus xanthine oxidase. However, cytosolic fraction protected against this inactivation by two mechanisms: 1) DTT carried over from homogenization medium and 2) its intrinsic SOD content. Soluble fraction was concentrated, dialyzed to remove 1,4-dithiothreitol (DTT), lyophilized, and suspended in a small volume of DTT-free buffer. It still protected against superoxide inactivation of Ca2+ pump. On Sephacryl-300 gel chromatography, protecting activity comigrated with SOD. DTT protected against inactivation, but glutathione and cysteine protected only partially. Neither sulfhydryl agents nor SOD could reverse the inactivation process. Ca2+ pump activity was abolished by dithionitrobenzoate and p-chloromercuric benzoate. Superoxide may inactivate ER Ca2+ pump by irreversibly modifying key sulfhydryl group(s) on pump molecule and SOD in coronary artery smooth muscle may partially protect against this inactivation.
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PMID:Protection of Ca pump of coronary artery against inactivation by superoxide radical. 253 68

The calcium ionophore A23187 causes endothelium-dependent contractions in canine basilar arteries. Removal of the endothelium, or treatment with indomethacin or superoxide dismutase (SOD), prevented the endothelium-dependent excitatory effect of the calcium ionophore. Catalase and deferoxamine were without effect. Superoxide anion generated by xanthine plus xanthine oxidase in the presence of catalase caused contractions of the vascular smooth muscle, which were abolished by SOD or heat inactivation of xanthine oxidase. The A23187-induced production of prostaglandins F2 alpha and E2 and thromboxane B2 was abolished by the removal of endothelium and by treatment with indomethacin but was not affected by the presence of SOD plus catalase. These observations are consistent with the hypothesis that superoxide anion, rather than prostaglandins generated by hydroperoxidase activity of cyclooxygenase, is an endothelium-derived contracting factor in canine cerebral arteries.
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PMID:Superoxide anion is an endothelium-derived contracting factor. 254 50

When micromolar concentrations of benzoyl peroxide (BPO) are added to rat liver mitochondria, inhibition of mitochondrial NADH-oxidase and succinoxidase is observed. The addition of 2,4-dinitrophenol, an uncoupler of oxidative phosphorylation, results in only partial release of this inhibition, suggesting that BPO inhibits both electron and energy transfer in mitochondria. Release of inhibition is also observed when an electron donor, N,N,N',N'-tetramethyl-p-phenylenediamine, is added, suggesting that inhibition occurs on the substrate side of cytochrome c. When BPO is added to respiring submitochondrial particles, only reduced cytochrome b is observed to accumulate in the difference spectrum (reduced minus oxidized) in a manner analogous to that observed in the presence of antimycin A. These results indicate that BPO interacts at coupling site II between cytochromes b and c1. When respiring SMP are treated with BPO in the presence of the spin trap 5,5-dimethyl-1-pyrroline-N-oxide, electron spin resonance signals attributable to the hydroxyl and superoxide adducts are observed. Catalase and superoxide dismutase inhibit the formation of these adducts, suggesting the involvement of both hydrogen peroxide and superoxide radicals in this process. BPO also induces rapid, large-amplitude swelling of mitochondria; the swelling is dependent on the presence of monovalent cations but is independent of the presence of calcium, oxygen, and respiratory substrate. BPO-induced swelling appears to be disassociated from radical production and lipid peroxidation.
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PMID:Benzoyl peroxide interaction with mitochondria: inhibition of respiration and induction of rapid, large-amplitude swelling. 273 1

The direct in vitro effects of alloxan on the Ca2+ handling by microsomal membranes isolated from dog mesenteric arteries were investigated. Preincubation of the vascular muscle microsomal membranes with alloxan showed a suppressive effect on both binding of Ca2+ (in the absence of ATP) and ATP-driven Ca2+ transport. Such an inhibition was time dependent, dose dependent, and temperature dependent. ATP-driven Ca2+ transport was much more susceptible to the inhibitory action of alloxan than Ca2+ binding under all experimental conditions examined. Alloxan inhibited ATP-driven Ca2+ transport at a comparable level over the entire period of Ca2+ uptake, but had no significant effect on the efflux of Ca2+ from preloaded microsomal membranes. This suggests that alloxan exerts its inhibitory effect on the ATP-driven Ca2+ transport via its action on the Ca-pump protein rather than the membrane permeability to Ca2+. Catalase and mannitol but not superoxide dismutase partially protected against such as inhibition by alloxan. The possible involvement of H2O2 mediating the inhibitory action of alloxan was further supported by the finding of a similar in vitro inhibitory effect of H2O2 on the ATP-driven Ca2+ transport by the vascular smooth muscle microsomes.
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PMID:Mechanism of inhibition by alloxan of ATP-driven calcium transport by vascular smooth muscle microsomes. 297 55

The role of divalent cations and reactive products of the respiratory burst were investigated in spontaneous tumor lysis mediated by inflammatory neutrophils (PMNs). Murine peritoneal PMNs, obtained five hours after intraperitoneal injection of bacteria, conjugated and lysed teratocarcinoma cells in chromium release and single-cell cytotoxicity assays. The presence of extracellular magnesium was required and was sufficient for tumor cell binding to PMNs. Postbinding lytic events depended upon the simultaneous presence of extracellular calcium and magnesium. Catalase and superoxide dismutase inhibited postbinding lytic events, indicating that production of reduced oxygen moieties was important. Scavengers of hydroxyl radicals could inhibit tumor cell binding, but none could affect postbinding lytic events. Neither could inhibitors of myeloperoxidase decrease tumor lysis. The ability of conjugating PMNs to lyse their bound targets correlated with their reduction of nitro blue tetrazolium (NBT). Optimal concentrations of phorbol myristate acetate (PMA) markedly increased the NBT positivity of PMNs and the killing of bound tumor cells. Even with optimal stimulation of the respiratory burst, however, there was still a significant number (19%) of bound targets that escaped lysis, suggesting active resistance to oxygen-mediated tumor cell injury.
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PMID:Spontaneous tumor cytolysis mediated by inflammatory neutrophils: dependence upon divalent cations and reduced oxygen intermediates. 300 19

A majority of the LDL preparations from various donors could be modified by incubation with endothelial cells from human arteries, veins and microvessels. These alterations comprise changes in electrophoretic mobility, buoyant density and lipid composition of LDL, the generation of thiobarbituric acid reactive substances in the medium, and a decrease in primary amino groups of LDL. Furthermore, the association of endothelial cell proteins with LDL was demonstrated by [35S]methionine incorporation and trichloroacetic acid precipitation of reisolated endothelial cell-modified LDL. After SDS-polyacrylamide gel electrophoresis of the reisolated modified LDL particles, radioactivity was mainly found at a molecular mass of 48 kDa and at one or two bands with a molecular mass of more than 100 kDa. The 48 kDa protein was identified as a latent plasminogen activator inhibitor. Cell viability was necessary for the cell-mediated LDL modification, which indicates that endothelial cells are actively involved in this process. The Ca2+ ionophore A23187 and monensin did not influence LDL modification. LDL modification was markedly inhibited by antioxidants. It was not prevented by cyclooxygenase and lipoxygenase inhibitors, which indicates that non-enzymatic lipid peroxidation is involved. Transition metal- (copper-) induced lipid peroxidation results in similar physiochemical alterations of the LDL particle as found with endothelial cells; it is prevented by the presence of superoxide dismutase. In contrast, endothelial cell LDL modification was not influenced by superoxide dismutase. Catalase or singlet oxygen and hydroxyl radical scavengers also did not affect it. We suggest that yet unidentified radicals or lipid peroxides are generated in the cells or on the cell membrane and that these reactive molecule(s) will react with LDL after leaving the cell. HDL and lipoprotein-depleted serum prevented LDL modification markedly, and to a larger extent than that by copper ions. We speculate that LDL modification by endothelial cells will only occur under those conditions in which the balance between the generation of reactive oxygen molecules and the cellular protection against these reactive species is disturbed.
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PMID:Role of endothelial cells and their products in the modification of low-density lipoproteins. 373 Apr 14


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