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1.
The effect of genetically determined glutathione deficiency on the fibroblast content of CuZn superoxide dismutase, Mn superoxide dismutase, catalase and glutathione peroxidase was investigated. No significant differences between glutathione-deficient and -proficient human fibroblasts were revealed. There was a large variation in the content of the investigated enzymes in fibroblasts grown and analysed on different occasions. Whereas the contents of CuZn superoxide dismutase, catalase and glutathione peroxidase did not deviate much from what has been found in other human cell-lines and tissues, the fibroblasts were found to contain exceptional amounts of Mn superoxide dismutase.  相似文献   

2.
Glutathione peroxidase (GSH-Px; glutathione: hydrogen peroxide oxidoreductase; EC 1.11.1.9), catalase (H2O2: H2O2 oxidoreductase; EC 1.11.1.6) and superoxide dismutase (superoxide: superoxide oxidoreductase; EC 1.15.1.1) were coisolated from human erythrocyte lysate by chromatography on DEAE-cellulose. Glutathione peroxidase was separated from superoxide dismutase and catalase by thiol-disulfide exchange chromatography and then purified to approximately 90% homogeneity by gel permeation chromatography and dye-ligand affinity chromatography. Catalase and superoxide dismutase were separated from each other and purified further by gel permeation chromatography. Catalase was then purified to approximately 90% homogeneity by ammonium sulfate precipitation and superoxide dismutase was purified to apparent homogeneity by hydrophobic interaction chromatography. The results for glutathione peroxidase represent an improvement of approximately 10-fold in yield and 3-fold in specific activity compared with the established method for the purification of this enzyme. The yields for superoxide dismutase and catalase were high (45 mg and 232 mg, respectively, from 820 ml of washed packed cells), and the specific activities of both enzymes were comparable to values found in the literature.  相似文献   

3.
Automated assays for catalase, glutathione peroxidase, glutathione reductase, and superoxide dismutase are presented. The assay for catalase is based on the peroxidatic activity of the enzyme. The glutathione peroxidase and reductase assays measure the consumption of NADPH following the reduction of t-butyl hydroperoxide and oxidized glutathione, respectively. The assay for superoxide dismutase is based on the reduction of cytochrome c. All assays utilize the Cobas FARA clinical automated analyzer and provide considerable time savings over the manual assays.  相似文献   

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6.
The effect of vanadium (V) on the activity of horseradish peroxidase, catalase, glutathione peroxidase, and superoxide dismutase has been studied. A competitive inhibition pattern was evident for vanadate ions on the activity of horseradish peroxidase (Ki = 41.2 microM). No significant inhibitory effects were found when V(V) was tested with catalase and when either V(IV) or V(V) were assayed with glutathione peroxidase. For the latter, the effect of V on the different components of the reaction system was investigated. V(V) did not significantly affect SOD activity when assayed with the sulfite method, which is devoid of interferences with V(V); however, there was an apparent inhibitory dose-response pattern for either V(IV) or V(V) using the pyrogallol assay, owing to an interference of pyrogallol with the metal. Besides, no significant binding of V(IV) or V(V) to the enzyme could be demonstrated. The lack of a direct inhibitory effect of V on the activity of the main antioxidant enzymes suggests that many biological and toxicological effects of V may be mediated more by oxidative reactions of the metal or of its complexes with physiologically relevant biomolecules than by a direct modulation of enzymatic activities.  相似文献   

7.
For preparationing the polyenzyme antioxidant complex, containing superoxide dismutase (SOD), catalase and horseradish peroxidase (HRP), the different successivities of those enzymes co-immobilization were compared. The optimum successivity is provided by simultaneous co-immobilization of covalently bound HRP with the SOD and catalase. The catalytic enzyme activity and the catalase operational stability was kinetically characterized in various samples. For one sample, the influence of ascorbate, glutathione and ethanol on the catalase kinetic parameters was studied. A possible scheme of different processes at the H2O2 decomposition in the presence of co-immobilized SOD, catalase, HRP and the substrates-reductans was discussed.  相似文献   

8.
Qualitative and quantitative differences in correlative and regressive links between superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase were assessed in the mice liver by two- and three-dimensional statistical methods. Paired linear correlation analysis indicated SOD-CAT tandem as the correlatively acting enzymatic pair. Three-dimensional analysis revealed uniform response surfaces which exhibited higher activities at disproportional values of the other two and lower activities at proportional activities of the other two enzymes. The direct effect of the enzymes on each other was positive [table: see text] while the effect of their product was always negative.  相似文献   

9.
The neutrophil enzyme myeloperoxidase generates hypochlorous acid (HOCl) at sites of inflammation. Glutathione peroxidase is very quickly inactivated by low concentration of HOCl. Inactivation of catalase is also rapid, but requires higher HOCl concentrations and the haem appears to be degraded. Inactivation of bovine CuZn superoxide dismutase is slower. Hence superoxide dismutase should not be easily inactivated by HOCl at sites of inflammation, which may contribute to its effectiveness as an anti-inflammatory agent and in minimizing reperfusion injury.  相似文献   

10.
CuZn superoxide dismutase, Mn superoxide dismutase, catalase, and glutathione peroxidase form the primary enzymic defense against toxic oxygen reduction metabolites in cells. To test the importance of these protective enzymes in the cellular radiation response, the enzymic activities of seven different human cell lines were determined in parallel with their clonogenic survival characteristics. A positive correlation between the content of glutathione peroxidase in cell lines and their extrapolation numbers (n) and quasithreshold doses (Dq) was detected. Between the cellular contents of the other enzymes and D0, n, and Dq no positive correlations could be established. An interesting finding was a very high Mn superoxide dismutase content in a malignant mesothelioma cell line P7, which had an extremely high D0, 5.0 Gy.  相似文献   

11.
The human promyelocytic leukemia cell line HL-60 undergoes induced myeloid differentiation, with acquisition of most polymorphonuclear leukocyte (PMN) functions, including generation of toxic oxygen species. We examined the concurrent changes in the cellular detoxifying defenses against superoxide and H2O2: superoxide dismutase, catalase, and the glutathione cycle. During induced differentiation, total superoxide dismutase activity declined to a level slightly more than 2-fold that of PMN, largely due to a decrease in Mn-superoxide dismutase; CuZn-superoxide dismutase showed virtually no change. Catalase activity declined only slightly (but significantly) to a level 1.3 that of PMN. GSH peroxidase activity fell and then rose back to its original level, remaining throughout differentiation more than 10-fold higher than activity in PMN. GSSG reductase activity declined to a level of 73% that of uninduced cells but twice that of PMN. GSH and GSSG contents both decreased, reaching equivalence to those of PMN. Concurrently, the ability of the cells to generate H2O2 increased 11-fold, a change similar to that previously reported for superoxide production. Thus, there is a paradoxical inverse relationship between the development of active oxygen generation and scavenging systems during myeloid differentiation in HL-60 cells.  相似文献   

12.
Superoxide dismutase, glutathione peroxidase and catalase activities were determined in isolated fetal rat hepatocytes of various ages and compared with the values of neonatal and adult cells. The developmental pattern of superoxide dismutase and glutathione peroxidase were very similar with a low constant activity in the fetal cells and a postnatal burst. On the contrary catalase begins to increase already since the 18th day of the fetal life. The results suggest a functional correlation of superoxide dismutase and glutathione peroxidase in the antioxidative enzyme defense of liver cells.  相似文献   

13.
The specific activities of Cu,Zn- and Mn-superoxide dismutases, of glutathione peroxidase and of catalase, the enzymes considered to be specifically involved in the defence of the cell against the partially reduced forms of oxygen, were determined as the function of postnatal age in the early (up to 60 days) period of rat brain development. The enzymes were assayed in the cytoplasmic fraction, in the crude mitochondrial fraction including peroxisomes, and in the mitochondria. The results show that the temporal changes of these enzymes cannot be correlated with each other, thus indicating that they do not concertedly parallel the increasing activity of aerobic brain metabolism during development. Specifically the cytoplasmic fraction shows a gradual increase of the Cu,Zn-superoxide dismutase activity with age, whereas the glutathione peroxidase activity is constant from birth. Furthermore the increase of the mitochondrial Mn-superoxide dismutase as a function of postnatal age is more remarkable than that of the cytoplasmic Cu,Zn-enzyme. Higher activities of catalase in adult animals are detectable only in the subcellular fraction containing peroxisomes, because of the modest catalase activity of the brain. These results indicate independent regulation of the expression of these enzyme activities in the process of brain differentiation and point to a relative deficiency of enzymic protection of the brain differentiation and point to a relative deficiency of enzymic protection of the brain against potentially toxic oxygen derivatives. This situation is similar to the pattern already described in the rat heart and in rat and mouse ascites-tumour cells, at variance with the much more efficient enzyme pattern present in rat hepatocytes.  相似文献   

14.
In mid-fifth-instar larvae of the southern armyworm, Spodoptera eridania, the subcellular distribution of four antioxidant enzymes—superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPOX), and glutathione reductase (GR)—were examined. Two-thirds (4.26 units ·mg protein?1) of the SOD activity was found in the cytosol, and one-thirds (2.13 units ·mg protein?1) in the mitochondria. CAT activity was unusually high and not restricted to the microsomal fraction where peroxisomes are usually isolated. The activity was distributed as follows: cytosol (163 units) mitochondria (125 units) and microsomes (119 units). Similar to CAT, the subcellular compartmentalization of both GPOX and GR was unusual. No activity was detected in the cytosol, but in mitochondria and microsomes, GR levels were 5.49 and 3.09 units. Although GPOX activity exhibited 14–16-fold enrichment in mitochondria and microsomes, respectively, over the 850g crude homogenate, the level was negligible (mitochondria = 1.4 × 10?3 units; microsomes = 1.6 × 10?3 units), indicating that this enzyme is absent. The unusual distribution of CAT has apparently evolved as an evolutionary answer to the absence of GR from the cytosol, and the lack of GPOX activity.  相似文献   

15.
Lipoperoxides in homogenates of regenerating rat liver increased from 6 hours after the operation and reached a peak (about 7 times the control level) 18-24 hours after the operation. The concentration of blood lipoperoxides rapidly decreased after the operation. The enzymatic activities of superoxide dismutase, catalase, and glutathione peroxidase, and vitamin E content in regenerating livers were also determined. Among these antioxidant factors, the catalase level changed markedly.  相似文献   

16.
Starved animals having low levels of erythropoietin in blood showed increased MDA, fluorescent pigments, and met-Hb values whereas the hemoglobin concentration decreased significantly on starvation. In vivo and in vitro studies with Ep reversed the effects of starvation and brought these values close to normal. The activities of the enzymes (SOD, catalase, GSH-PX, GR G6PD, and 6PGD) which protect the RBC membrane directly or indirectly from peroxidative threat, decreased on starvation and restored to normal levels after Ep treatment.  相似文献   

17.
Glutathione-S-transferase (GST), superoxide dismutase (SOD), Xanthine oxidase, selenium-dependent glutathione peroxidase (GPxI), catalase activities and malondialdehyde (MDA) content were determined in liver of three groups of exercised rats (E) viz., one day (E1), 10 days (E10) and 60 days (E60). GST, SOD and xanthine oxidase activities increased significantly with the increase in exercise period. Lipid peroxidation, expressed in terms of MDA formation, also increased in the liver of all the three groups. But catalase activity decreased significantly during exercise. Further, GPxI did not show any significant change in its activity in response to exercise. Our findings indicate that: 1) The significant increase in GST activity suggests their induction aimed at counteracting the oxidant stress induced during exercise; 2) The significant increase in xanthine oxidase and SOD activities indicates the generation of more superoxide anion radicals and their removal, respectively. 3) The significant reduction in catalase activity denotes the decreased formation of hydrogenperoxides during exercise; and 4) The pattern of changes in the activity level of GPxI indicate its least participation during exercise. However, in another way it is giving a scope for the involvement of GPxII associated with GST in the reduction of organic hydroperoxides. Further more, the relative increase in MDA is considered as the indicator of the rate of lipid peroxidation in the wake of exhaustive exercise.  相似文献   

18.
Under normal conditions, antioxidants at the corneal surface are balanced with the production of reactive oxygen species without any toxic effects. Danger from oxidative stress appears when natural antioxidants are overwhelmed leading to antioxidant/prooxidant imbalance. The aim of the present study was to examine the activities of enzymes contributing to the antioxidant/prooxidant balance in normal corneal epithelium of various mammals. The enzyme activities of antioxidant superoxide dismutase and glutathione peroxidase, as well as prooxidant xanthine oxidoreductase/xanthine oxidase were examined using biochemical methods. Results show that superoxide dismutase activity is high in rabbits and guinea pigs, whereas in pigs the activity is low and in cows it is nearly absent. In contrast, glutathione peroxidase activity is high in cows, pigs and rabbits, whereas in guinea pigs the activity is low. As far as prooxidant enzymes are concerned, elevated xanthine oxidoreductase/xanthine oxidase activities were found in rabbits, lower activities in guinea pigs, very low activity in cows and no activity in pigs. In conclusion, the above results demonstrate inter-species variations in activities of enzymes participating in antioxidant/prooxidant balance in the corneal epithelium. It is suggested that the levels of antioxidant and prooxidant enzymes studied in the corneal epithelium might be associated with the diurnal or nocturnal activity of animals. UV rays decompose hydrogen peroxide to damaging hydroxyl radicals and perhaps for this reason large animals with diurnal activity (cow, pig) require more effective peroxide removal (high glutathione peroxidase activity) together with the suppression of peroxide production (low superoxide dismutase activity, low xanthine oxidoreductase activity).  相似文献   

19.
Exogenous superoxide dismutase, catalase and scavengers of the hydroxyl radical protect pancreatic-islet cells against the toxic actions of alloxan in vitro [Grankvist et al. (1979) Biochem. J. 182, 17--25]. To test whether the extraordinary sensitivity of islet cells to alloxan is due to a deficiency of endogenous enzymes protecting against oxygen-reduction products, we assayed CuZn-superoxide dismutase, Mn-superoxide dismutase, catalase and glutathione peroxidase in mouse islets and other tissues. To correct for any blood contamination, haemoglobin was also measured in the tissue samples. Pancreatic islets were found to belong to tissues with relatively little activity of the protective enzymes. However, the deviation from other tissues in this respect is probably not large enough to explain the especially great susceptibility of islet cells to alloxan.  相似文献   

20.
Four primary antioxidant enzymes were measured in both human and rat glioma cells. Both manganese-containing superoxide dismutase (MnSOD) and copper-zinc-containing superoxide dismutase (CuZnSOD) activities varied greatly among the different glioma cell lines. MnSOD was generally higher in human glioma cells than in rat glioma cells and relatively higher than in other tumor types. High levels of MnSOD in human glioma cells were due to the high levels of expression of MnSOD mRNA and protein. Heterogeneous expression of MnSOD was present in individual glioma cell lines and may be due to subpopulations or cells at different differentiation stages. Less difference in CuZnSOD, catalase, or glutathione peroxide was found between human and rat glioma cells. The human glioma cell lines showed large differences in sensitivity to the glutathione modulating drugs 1,3-bis (2-chloroethyl)-1-nitrosourea (BCNU) and buthionine sulfoximine (BSO). A good correlation was found between sensitivity to BCNU and the activities of catalase in these cell lines. Only one cell line was sensitive to BSO and this line had low CuZnSOD activity.  相似文献   

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