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

---

Query: UNIPROT:P04040 (Catalase)
3,577 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Bleaching of chlorophyllin, a water soluble copper containing porphyrin molecule, was investigated with regard to the potential role of active oxygen intermediate involvement. It was found that the bleaching was highly aerobic and also biphasic in nature. The aerobic photobleaching and the dark bleaching were effectively prevented by the addition of reductants such as ascorbate and cysteine. In addition, the reductant and peroxyl radical scavenger, Trolox, was highly effective in preventing bleaching. Catalase was moderately effective in preventing photobleaching whereas peroxidase and superoxide dismutase hastened the photobleaching process. It is concluded that the bleaching of chlorophyllin is a peroxidative process which does not involve singlet oxygen, superoxide, nor the .OH radical.
...
PMID:Active oxygen intermediates and chlorophyllin bleaching. 880 3

We studied the effect of water-soluble antioxidants on the cell energetics in multiple organs in rats in response to a 20% total body surface area third-degree burn injury. Liver, lung, and heart tissue were studied. Cell energetics were measured as tissue energy charge potential (ECP), adenosine triphosphate (ATP) content, and total adenine nucleotides. The enzymatic antioxidant catalase was used as a marker of endogenous cell antioxidant activity, especially to hydrogen peroxide. The water-soluble antioxidants glutathione, N-acetylcysteine, and vitamin C were given orally beginning at the time of burn injury and for the 6-day study period. All rats were fluid resuscitated according to the Parkland formula. The mortality rate was 0% for this size burn. The ECP in lung, liver, and heart, was normal on day 1 after the burn injury. However, the ECP was significantly decreased from the controls in the liver by day 3, with a peak decrease at day 6 as inflammation increased. A decrease in the heart ECP occurred between day 3 and day 6. Total adenine nucleotides did not decrease, indicating the decrease in ECP to be the result of a decrease in ATP. ECP remained normal in the lung. Catalase was also decreased in the liver and the heart and remained at normal levels in the lung. The decrease in the liver and heart ECP and ATP was eliminated with the oral antioxidant administration after the burn injury. We conclude that a modest burn injury decreases cellular energy charge in the heart and liver not immediately after burn but 3 to 6 days later. The decrease in antioxidant activity precedes the decrease in ECP. The lung appears to be protected. Water-soluble antioxidants, given after burn injury, prevent the altered cell energetics-strongly suggesting a cause-and-effect relationship between increased oxidant release with inflammation, decreased antioxidant activity, and altered cell energetics.
...
PMID:Antioxidants prevent the cellular deficit produced in response to burn injury. 888 59

Four putative heat-tolerant tomato (Lycopersicum esculentum) cultivars (Tamasabro, Heat Wave, LHT-24, and Solar Set) and one putative heat-sensitive tomato cultivar (Floradade) were grown in the field under non-stress (average daily temperature of 26 degrees C) and heat-stress (average daily temperature of 34 degrees C) conditions. At anthesis, approximately five weeks after being transplanted to the field, leaf samples were collected for antioxidant analyses. Yield was determined by harvesting ripe fruit seven weeks after the collection of leaf samples. Heat stress resulted in a 79.1% decrease in yield for the heat-sensitive Floradade, while the fruit yield in the heat-tolerant cultivars Heat Wave, LHT-24, Solar Set, and Tamasabro was reduced 51.5%, 22.1%, 43.8%, and 34.8% respectively. When grown under heat stress, antioxidant activities were also greater in the heat-tolerant cultivars. Superoxide dismutase (SOD) activity increased up to 9-fold in the heat-tolerant cultivars but decreased 83.1% in the heat-sensitive Floradade. Catalase, peroxidase, and ascorbate peroxidase activity increased significantly in all cultivars. Only Heat Wave showed a significant increase in glutathione reductase in response to heat stress but all heat-tolerant cultivars exhibited significantly lower oxidized ascorbate/reduced ascorbate ratios, greater reduced glutathione/oxidized glutathione rations, and greater alpha-tocopherol concentrations compared to the heat-sensitive cultivar Floridade. These data indicate that the more heat-tolerant cultivars had an enhanced capacity for scavenging active oxygen species and a more active ascorbate-glutathione cycle and suggest a strong correlation between the ability to up-regulate the antioxidant defense system and the ability of tomatoes to produce greater yields when grown under heat stress.
...
PMID:The relationship between yield and the antioxidant defense system in tomatoes grown under heat stress. 890 41

Catalase activity in cell cultures of fetal rat mesencephalon was decreased by 42 and 50%, respectively, after exposure to L-3,4-dihydroxyphenylalanine (L-DOPA, 100 microM) or dopamine (100 microM) for 48 h. Catalase activity was also decreased 21% by 10 microM hydroquinone. Ascorbic acid (200 microM), an agent that suppresses the autoxidation of L-DOPA and dopamine, blocked the anti-catalase effect of L-DOPA, but not that of dopamine. Inhibitors of the A and B forms of monoamine oxidase (20 microM clorgyline plus 20 microM pargyline) had no effect on the anti-catalase action of either L-DOPA or dopamine. The latter results suggest that products of the oxidative deamination of dopamine by monoamine oxidase are not involved in the suppression of catalase activity. However, autoxidation reactions of L-DOPA may play a role since ascorbate suppressed the anti-catalase effect of L-DOPA. On the contrary, the basis for the failure of ascorbate to similarly block the anti-catalase effect of dopamine is uncertain. L-DOPA and dopamine (25 microM) also inhibited crystalline catalase in solution after incubation for 1 h at neutral pH (40-50% inhibition). Inhibition was blocked by 0.45 M ethanol, indicating a need for autoxidation and the formation of compound II, which is an enzymatically inactive form of catalase. The ability to model the enzyme inhibition in purely chemical experiments indicates a probable mechanism for loss of enzymatic activity in cell cultures. Inhibition of catalase may contribute to cell damage during incubation of cultures with L-DOPA, dopamine, or other autoxidizable compounds.
...
PMID:Inhibition of catalase in mesencephalic cultures by L-DOPA and dopamine. 911 32

Dopamine (100 microM, 10-30 min) inhibits/inactivates the MgATP-dependent generation of a transmembrane proton electrochemical gradient in chromaffin granule ghosts. The dopamine dependent inhibition was enhanced by adding soluble dopamine beta-monooxygenase (DBM, 0.2 U/ml) and completely prevented by ascorbate (1 mM), dithiothreitol (2 mM) and approximately 80% by the DBM inhibitor fusaric acid (10 microM). This indicates that the inhibition is caused by the dopamine semiquinone free radical generated during DBM-dependent dopamine oxidation. Catalase, superoxide dismutase or both did not prevent the inhibition, and DBM-catalysed dopamine oxidation did not change the basal level of lipid peroxidation, excluding the involvement of reactive oxygen species as being responsible for the inhibition. N-ethylmaleimide-sensitive ATPase activity (i.e. the proton translocating ATPase) in the vesicle membranes was inhibited during dopamine incubation, indicating that the toxic metabolite (dopamine semiquinone) inhibits proton pumping by inhibiting the endogenous vacuolar H(+)-ATPase. As this proton pump represents the driving force for the vesicular uptake and storage of catecholamines, the dopamine dependent inhibition, if taking place in vivo, may inhibit dopamine uptake in storage vesicles in sympathetic neurons, e.g. as observed in the myopathic hamster heart.
...
PMID:Dopamine oxidation generates an oxidative stress mediated by dopamine semiquinone and unrelated to reactive oxygen species. 922 Mar 58

'Long-Life CiLi' ('CiLi') oral liquid, is composed of superoxide dismutase (SOD), polysacchairide, vitamin C, vitamin E and trace elements which were all extracted from a natural plant fruit Cili (Rosa roxburghii Tratt) in Guizhou, China. A set of indices were evaluated after administration of 'CiLi' 10 ml Bid, for two months in 50-75 years old healthy people, the mean value of NK cell activity (22.4 +/- 10.8-->27.5 +/- 12.9%, P < 0.05), SOD (453.0 +/- 24.2-->468.6 +/- 21.3 micrograms/gHb, P < 0.001), Catalase (15.5 +/- 1.7-->17.4 +/- 3.0 U/mgHb, P < 0.001) and GSH content (2.3 +/- 0.3-->2.6 +/- 0.5 mg/gHb, P < 0.001) in erythrocytes and 'delta CO, CI, SV, SI, LVET, LVETI and AC' values increased significantly, while the serum LPO level (4.20 +/- 0.78-->3.78 +/- 0.50 nmol/ml, P < 0.001), total microcirculation weighed value (1.87 +/- 1.0-->0.92 +/- 0.5, P < 0.001), delta PVR (-241.7 +/- 733.2-->187.9 +/- 938.2, P < 0.05) and the light reaction time (Simple RT, red light: 383 +/- 128-->332 +/- 68.9 ms, P < 0.05; selective RT: red light 709 +/- 287-->566 +/- 119 ms, P < 0.05; green light 639 +/- 162-->536 +/- 80 ms, P < 0.01) decreased significantly. There were no significant differences in the control group. The mean life span of fruit flies were significantly elongated for low, medium and high concentrations 'CiLi' treatment groups than in the control group (Female: 57.6 +/- 11.3-->62.1 +/- 12.8; 69.6 +/- 14.7; 62.6 +/- 12 days; P < 0.05 approximately 0.001. Male: 56.3 +/- 9.6-->64.9 +/- 12.4; 64.5 +/- 14.5; 64.8 +/- 14.1 days, P < 0.001). It is suggested that 'CiLi' has an aging retarding and geroprotection effect.
...
PMID:The aging retarding effect of 'Long-Life CiLi'. 922 19

This study showed that the inhibition of cell growth in 3T6, induced by the supplementation of ascorbate at 0.5 mM in cultured medium, was prevented by the addition of catalase in the range of 25-750 units/mL regardless of the degree of activity. However, cytotoxicity induced by concentrations of more than 2 mM ascorbate could not be prevented even when a high level of catalase (5,000 units/mL) was added to the medium. Catalase activity in medium supplemented with ascorbate decreased with incubation time; the higher the concentration of ascorbate, the greater the decrease in catalase activity. These results indicate that even though catalase is present at a high concentration in the medium, it cannot prevent cytotoxicity by a high concentration of ascorbate because the oxygen radical derived from ascorbate inhibits its activity. We therefore investigated whether the inhibition of catalase activity by ascorbate could be observed in animal tissues. The catalase activity in the tissues of guinea pigs 6h after the administration of ascorbate was lower than that in non-administered animals. When guinea pigs were fed diets containing 5 mg or 100 mg ascorbate/animal over a 90 weeks period, a clear affect on catalase activity in the high-dose ascorbate group as compared to that in the low-dose ascorbate group was not observed.
...
PMID:Effect of high concentration of ascorbate on catalase activity in cultured cells and tissues of guinea pigs. 926 19

Hydrogen peroxide (H2O2) has been implicated in many stress conditions. Control of H2O2 levels is complex and dissection of mechanisms generating and relieving H2O2 stress is difficult, particularly in intact plants. We have used transgenic tobacco with approximately 10% wild-type catalase activity to study the role of catalase and effects of H2O2 stress in plants. Catalase-deficient plants showed no visible disorders at low light, but in elevated light rapidly developed white necrotic lesions on the leaves. Lesion formation required photorespiratory activity since damage was prevented under elevated CO2. Accumulation of H2O2 was not detected during leaf necrosis. Alternative H2O2-scavenging mechanisms may have compensated for reduced catalase activity, as shown by increased ascorbate peroxidase and glutathione peroxidase levels. Leaf necrosis correlated with accumulation of oxidized glutathione and a 4-fold decrease in ascorbate, indicating that catalase is critical for maintaining the redox balance during oxidative stress. Such control may not be limited to peroxisomal H2O2 production. Catalase functions as a cellular sink for H2O2, as evidenced by complementation of catalase deficiency by exogenous catalase, and comparison of catalase-deficient and control leaf discs in removing external H2O2. Stress analysis revealed increased susceptibility of catalase-deficient plants to paraquat, salt and ozone, but not to chilling.
...
PMID:Catalase is a sink for H2O2 and is indispensable for stress defence in C3 plants. 930 23

Nuclear transcription factor kappa B (NF-kappa B) is a multiprotein complex that regulates a variety of genes important for immunity and inflammation. The present study investigates the silica-induced activation of this transcription factor in mouse macrophage cell line RAW 264.7 cells, the role of free radical reactions in the mechanism of the activation, and its possible inhibition. Tetrandrine, a benzylisoquinoline alkaloid, which has been used as an antifibrotic drug to treat the lesions of silicosis and has been characterized as a hydroxyl radical (.OH) scavenger, inhibited the NF-kappa B activation induced by silica, lipopolysaccharide (LPS), and phorbol 12-myristate 13-acetate (PMA). Catalase, metal chelator, deferoxamine, and the silanol group (SiOH) blocker, poly(2-vinylpyridine-N-oxide) (PVPNO), also inhibited silica-induced NF-kappa B activation. Electron spin resonance (ESR) spin trapping measurements show that both deferoxamine and PVPNO decreased silica-mediated .OH radical generation from H2O2. It is shown that Fe(II) and not Fe(III) is able to cause NF-kappa B activation. The antioxidant, ascorbate, attenuated the NF-kappa B activation induced by silica but not by LPS. The .OH radical scavenger, sodium formate, inhibited NF-kappa B activation induced by silica but had only a minor effect on NF-kappa B activation induced by LPS. The results indicate that silica-mediated free radical generation via the Fenton or Fenton-like reaction (M(n)+ + H2O2-->M(n + 1)+ + OH- + .OH) and silanol groups on the silica surface play an important role in silica-induced NF-kappa B activation.
...
PMID:Role of hydroxyl radical in silica-induced NF-kappa B activation in macrophages. 951 78

Scission of plant cell wall polysaccharides in vivo has generally been assumed to be enzymic. However, in the presence of l-ascorbate, such polysaccharides are shown to undergo non-enzymic scission under physiologically relevant conditions. Scission of xyloglucan by 1 mM ascorbate had a pH optimum of 4.5, and the maximum scission rate was reached after a 10-25-min delay. Catalase prevented the scission, whereas added H2O2 (0.1-10 mM) increased the scission rate and shortened the delay. Ascorbate caused detectable xyloglucan scission above approx. 5 microM. Dehydroascorbate was much less effective. Added Cu2+ (>0.3 microM) also increased the rate of ascorbate-induced scission; EDTA was inhibitory. The rate of scission in the absence of added metals appeared to be attributable to the traces of Cu (2.8 mg.kg-1) present in the xyloglucan. Ascorbate-induced scission of xyloglucan was inhibited by radical scavengers; their effectiveness was proportional to their rate constants for reaction with hydroxyl radicals (.OH). It is proposed that ascorbate non-enzymically reduces O2 to H2O2, and Cu2+ to Cu+, and that H2O2 and Cu+ react to form .OH, which causes oxidative scission of polysaccharide chains. Evidence is reviewed to suggest that, in the wall of a living plant cell, Cu+ and H2O2 are formed by reactions involving ascorbate and its products, dehydroascorbate and oxalate. Systems may thus be in place to produce apoplastic .OH radicals in vivo. Although .OH radicals are often regarded as detrimental, they are so short-lived that they could act as site-specific oxidants targeted to play a useful role in loosening the cell wall, e.g. during cell expansion, fruit ripening and organ abscission.
...
PMID:Oxidative scission of plant cell wall polysaccharides by ascorbate-induced hydroxyl radicals. 960 Oct 81


<< Previous 1 2 3 4 5 6 7 8 9 10 Next >>

---