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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.
Antibodies were prepared against glutathione peroxidase, superoxide dismutase, and catalase. Inhibition of the enzyme activity was obtained with anti-Gpx and anti-SOD antibodies but not with anti-CAT antibodies. The antibodies were then injected into human fibroblasts and bovine chondrocytes in culture either under normal conditions or under 1 atm of oxygen. The injected anti-Gpx and anti-SOD antibodies increased the mortality rate of the fibroblasts incubated under 1 atm of oxygen. However, when cells were incubated under normal atmosphere, anti-Gpx antibodies inhibited the division while anti-SOD antibodies increased this capacity. Anti-Gpx antibodies injected into chondrocytes decreased their viability. Injection of control antiserum had no effect. These data stress the primary importance of Gpx as antioxidant under all conditions and the relative efficiency of SOD according to the balance between the radical production and the activity of the other antioxidant systems.  相似文献   

3.
Superoxide dismutase (SOD), glutathione peroxidase (GPX), glutathione S-transferase (GST) and glutathione reductase (GR) play crucial roles in balancing the production and decomposition of reactive oxygen species (ROS) in living organisms. These enzymes act cooperatively and synergistically to scavenge ROS, as not one of them can singlehandedly clear all forms of ROS. In order to imitate the synergy of the enzymes, we designed and generated a recombinant protein, which comprises of a Schistosoma japonicum GST (SjGST) and a bifunctional 35-mer peptide with SOD and GPX activities. The engineered protein demonstrated SOD, GPX and GST activities simultaneously. This trifunctional enzyme with SOD, GPX and GST activities is expected to be the best ROS scavenger.  相似文献   

4.
The enzymatic antioxidant defences of mammalian cells include copper-zinc superoxide dismutase (SOD)(Cu Zn-SOD; EC 1.15.1.1) which catalyses the dismutation of superoxide anions (O2.-) to hydrogen peroxide(H2, O2)and a seleno-dependent glutathione peroxidase (GSH-px) (GSH-px; EC 1.11.1.9) which catalyses the degradation of H2O2 to H2O and O2. The measurement of these enzyme activities is often used as a possible biological index of oxidative stress in various clinical conditions. Complete understanding of such information requires knowledge of the random biological fluctuation of the enzyme activity which occurs in each individual. In the present investigation we examined this normal variability in 12 healthy volunteers (four women and eight men) aged 23–45 years, over 6 months. The intra-individual coefficients of variation (estimated using analysis of variance techniques) were 15% (SOD) and 13% (GSH-px). The analytical goal for imprecision was achieved for both enzymes, i.e. it was less than one half of the measured intra-individual variation. Both enzymes showed marked individuality, indicating that an individual's reference values are more useful than population-based data. The critical difference required for significant changes in serial results is 45% for SOD and 40% for GSH-px.  相似文献   

5.
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   

6.
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   

7.
8.
In this study, the effects of UVA and UVB rays on antioxidant enzymes (superoxide dismutase, glutathione peroxidase, catalase) were examined in the corneal epithelium. The corneas of albino rabbits were irradiated with a UV lamp generating UVA (365 nm wavelength) or UVB rays (312 nm wavelength), 1 x daily for 5 min, from a distance of 0.03 m, over 4 days (shorter procedure) or 8 days (longer procedure). In contrast to UVA rays, which did not evoke significant disturbances, UVB rays changed the activities of antioxidant enzymes. The longer repeated irradiation with UVB rays was performed, the deeper the observed decrease in antioxidant enzymes. The shorter procedure evoked a more profound decrease of glutathione peroxidase and catalase (the enzymes cleaving hydrogen peroxide) than of superoxide dismutase, an enzyme scavenging superoxide radical and producing hydrogen peroxide during the dismutation reaction of a superoxide free radical. This may contribute to an insufficient hydrogen peroxide cleavage at the corneal surface and danger to the cornea from oxidative damage. After the longer procedure (UVB rays), the activities of all antioxidant enzymes were very low or completely absent. In conclusion, repeated irradiation of the cornea with UVB rays evokes a deficiency in antioxidant enzymes in the corneal epithelium, which very probably contributes to the damage of the cornea (and possibly also deeper parts of the eye) from UVB rays and the reactive oxygen products generated by them.  相似文献   

9.
Superoxide dismutase (SOD), glutathione peroxidase (GPX), glutathione S-transferase (GST) and glutathione reductase (GR) play crucial roles in balancing the production and decomposition of reactive oxygen species (ROS) in living organisms. These enzymes act cooperatively and synergistically to scavenge ROS, as not one of them can singlehandedly clear all forms of ROS. In order to imitate the synergy of the enzymes, we designed and generated a recombinant protein, which comprises of a Schistosoma japonicum GST (SjGST) and a bifunctional 35-mer peptide with SOD and GPX activities. The engineered protein demonstrated SOD, GPX and GST activities simultaneously. This trifunctional enzyme with SOD, GPX and GST activities is expected to be the best ROS scavenger.  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 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   

12.
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   

13.
Catalase and superoxide dismutase in Escherichia coli   总被引:9,自引:0,他引:9  
We assessed the roles of intrabacterial catalase and superoxide dismutase in the resistance of Escherichia coli to killing by neutrophils. E. coli in which the synthesis of superoxide dismutase and catalase were induced by paraquat 10-fold and 5-fold, respectively, did not resist killing by neutrophils. When bacteria were allowed to recover from the toxicity of paraquat for 1 h on ice and for 30 min at 37 degrees C, they still failed to resist killing by neutrophils. Induction of the synthesis of catalase 9-fold by growth in the presence of phenazine methosulfate did not render E. coli resistant to killing by either neutrophils or by H2O2 itself. The lack of protection by intrabacterial catalase from killing by neutrophils could not be attributed to an impermeable bacterial membrane; the evolution of O2 from H2O2 was no less rapid in suspensions of E. coli than in lysates. The failure of intrabacterial catalase or superoxide dismutase to protect bacteria from killing by neutrophils might indicate either that the flux of O-2 and H2O2 in the phagosome is too great for the intrabacterial enzymes to alter or that the site of injury is at the bacterial surface.  相似文献   

14.
Abstract

Objectives

The objective of this study was to investigate the effects of catechin and epicatechin on the activity of the endogenous antioxidant enzymes superoxide dismutase (SOD) and glutathione peroxidase (GPx) (as well as the total antioxidant capacity (TAC)) of rats after intra-peritoneal (i.p.) administration.

Methods

Twenty-four Wistar rats were randomly divided into two groups: the experimental group which was administered daily with a 1:1 mixture of epicatechin and catechin at a concentration of 23 mg/kg body weight for 10 days and the control group which was injected daily with an equal amount of saline. Blood and urine samples were collected before and after the administration period, as well as 10 days after (follow-up).

Results

Intra-peritoneal administration of catechins led to a potent decrease in GPx levels and a significant increase in SOD levels. TAC was significantly increased in plasma and urine. Malonaldehyde levels in urine remained stable. In the animals treated with catechins, SOD activity showed a moderate negative correlation with GPx activity.

Discussion

Boosting the activity of the antioxidant enzymes could be a potential adjuvant approach for the treatment of the oxidative stress-related diseases.  相似文献   

15.
16.
For constructing a bifunctional antioxidative enzyme with both superoxide dismutase (SOD) and glutathione peroxidase (GPx) activities, a supramolecular artificial enzyme was successfully constructed by the self-assembly of the Mn(III)meso-tetra[1-(1-adamantyl methyl ketone)-4-pyridyl] porphyrin (MnTPyP-M-Ad) and cyclodextrin-based telluronic acid (2-CD-TeO3H) through host-guest interaction in aqueous solution. The self-assembly of the adamantyl moieties of Mn(III) porphyrin and the β-CD cavities of 2-CD-TeO3H was demonstrated by the NMR spectra. In this supramolecular enzyme model, the Mn(III) porphyrin center acted as an efficient active site of SOD and tellurol moiety endowed GPx activity. The SOD-like activity (IC50) of the new catalyst was found to be 0.116 μM and equals to 2.56% of the activity of the native SOD. Besides this, supramolecular enzyme model also showed a high GPx activity, and a remarkable rate enhancement of 27-fold compared to the well-known GPx mimic ebselen was observed. More importantly, the supramolecular artificial enzyme showed good thermal stability.  相似文献   

17.
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   

18.
19.
Studies of Km for glutathione peroxidase (GPx) and activities of superoxide dismutase and GPx were carried out in liver and erythrocytes of rats kept on either the normal semisynthetic diet or a high-fat diet with increased content of Cu, Zn, Mn, and Se. The diet containing microelement additions caused the increase in TBH affinity of liver and erythrocyte GPx, as well as the decrease of liver SOD observed on the 14th day of the treatment of rats with the high-fat diet with additional increase of Cu, Zn, Mn, and Se.  相似文献   

20.
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   

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