Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:P30044 (antioxidant enzyme)
 8,037 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

To analyse nodular antioxidant enzyme expression in response to salt stress, Phaseolus vulgaris genotype BAT477 was inoculated with reference strain CIAT899, and treated with 50 mM NaCl. Plant growth, nodulation and nitrogen fixing activity were analysed. Results showed that: (1) all parameters, particularly in nodules, were affected by salt treatments, and (2) confirmed preferential growth allocation to roots. The ARA was significantly decreased by salt treatments. Protein dosage confirmed that nodules were more affected by salt treatment than were roots. We analysed superoxide dismutase, catalase, ascorbate peroxidase and peroxidase in nodules, roots and a free rhizobial strain. Our results indicated that SOD and CAT nodular isozymes had bacterial and root origins. The SOD expressed the same CuZn, Fe and Mn SOD isoforms in nodules and roots, whereas in free rhizobia we found only one Fe and Mn SOD. APX and POX nodule and root profiles had only root origins, as no rhizobial band was detected. Under salt stress, plant growth, nitrogen fixation and activities of antioxidant defense enzymes in nodules were affected. Thus, these enzymes appear to preserve symbiosis from stress turned out that NaCl salinity lead to a differential regulation of distinct SOD and POX isoenzyme. So their levels in nodules appeared to be consistent with a symbiotic nitrogen fixing efficiency hypothesis, and they seem to function as the molecular mechanisms underlying the nodule response to salinity.
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PMID:Changes in ascorbate peroxidase, catalase, guaiacol peroxidase and superoxide dismutase activities in common bean (Phaseolus vulgaris) nodules under salt stress. 1614 19

The regulation of the antioxidant defence system by ultraviolet-B (UV-B) was determined in a marine macroalga Ulva fasciata Delile exposed to low (0.5, 1 W m(-2)), medium (2.5, 5 W m(-2)), and high (10, 20 W m(-2)) UV-B irradiance. UV-B > or =2.5 W m(-2) increased H2O2 contents that are positively correlated with lipid peroxidation and total peroxide contents. Inhibition of the UV-B-induced H2O2 increase by a specific O2.- scavenger, 1,2-dihydroxy-benzene-3,5-disulphonic acid, shows that O2.- is the primary source of H2O2. Superoxide dismutase activity was increased by UV-B with a peak at 2.5 W m(-2), which did not match the H2O2 pattern. Alleviation of UV-B-induced oxidative damage by a H2O2 scavenger, dimethylthiourea, and a free radical scavenger, sodium benzoate, which inhibited UV-B-induced H2O2 accumulation, suggests that oxidative damage caused by UV-B > or = 2.5 W m(-2) is ascribed to accumulated H2O2. However, a decrease in growth rate and TTC reduction ability only at high UV-B doses indicates that the defence and repairing systems operate at low and medium UV-B doses. H2O2 not only can be excreted but can also be detoxified via the ascorbate-glutathione cycle. Increases in catalase, peroxidase, ascorbate peroxidase, and glutathione reductase activities and ascorbate (AsA) and glutathione pools, as well as AsA regeneration ability, function to keep the balance of cellular H2O2 under low UV-B doses. Dehydroascorbate reductase and monodehydroascorbate reductase are responsible for AsA regeneration under low and medium UV-B radiation, respectively. The appearance of oxidative damage in medium and high UV-B flux is attributable to a lower induction of the ascorbate-glutathione cycle as an antioxidant defence system. Overall, the availability of antioxidants and the induction of antioxidant enzyme activities for detoxifying reactive oxygen species (ROS) are regulated in U. fasciata against UV-B-induced oxidative stress, and experiments using ROS scavengers demonstrate that the antioxidant defence system is modulated by O2.- or H2O2.
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PMID:Ultraviolet-B-induced oxidative stress and responses of the ascorbate-glutathione cycle in a marine macroalga Ulva fasciata. 1615 54

The activities of antioxidant enzymes viz. glutathione reductase, GR; superoxide dismutase, SOD; peroxidase, POD; catalase, CAT and glutathione-S-transferase, GST and alkaloid accumulation were investigated in leaf pairs (apical, middle, basal) and in roots of Catharanthus roseus seedlings under the conditions of different nitrogen sources (20 mM KNO(3) and 2 mM NH(4)Cl) and salinity, in the absence (non-saline control) and in the presence of 100 mM NaCl in the nutrient solution. Salinity caused a reduction in plant biomass. The biomass production of ammonium-fed plants was lower than that of nitrate-fed plants. The antioxidant enzymes exhibited higher activity in saline-treated plants. Changes in antioxidant enzyme activity caused by different nitrogen sources differed in all leaf pairs, as well as in roots of C. roseus. Ammonium-fed plants showed higher CAT, GR and GST activity in leaf pairs as well as in roots, while POD and SOD activity were higher in nitrate-fed plants. Higher peroxidase activity concomitant with the increased accumulation of alkaloid was found in all leaf pairs, as well as in roots of C. roseus of NO(3)(-) fed plants as compared to NH(4)(+) fed plants.
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PMID:Effect of salinity and different nitrogen sources on the activity of antioxidant enzymes and indole alkaloid content in Catharanthus roseus seedlings. 1636 Jul 99

Peroxiredoxin 6 (Prd x 6) is a novel peroxidase enzyme that is expressed at a high level in the lung. We tested the hypothesis that transgenic (Tg) mice overexpressing Prd x 6 would exhibit increased resistance to hyperoxia-induced lung injury. Wild-type and Tg mice were exposed to 100% O(2) and evaluated for survival, lung histopathology, total protein, and nucleated cells in bronchoalveolar lavage fluid (BALF), and oxidation of lung protein and lipids. Prd x 6 protein expression and enzyme activity were approximately 3-fold higher in Tg lungs compared with wild-type. Tg mice survived longer during exposure to 100% O(2) (LT(50) 104+/-2.8 h in Tg versus 88.9+/-1.1 h for wild-type). Lung wet/dry weight ratio and total protein and nucleated cell count in lung lavage fluid were significantly greater in wild-type mice at 72 and 96 h of hyperoxia compared with Tg mice. At 96 h of hyperoxia, Tg mice had less epithelial cell necrosis, perivascular edema, and inflammatory cell recruitment by light microscopy, and lower TBARS and protein carbonyls in lung homogenate (P<0.05). These results show that Tg mice have increased defense against lung injury in hyperoxia, providing evidence that Prd x 6 functions as a lung antioxidant enzyme.
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PMID:Transgenic mice overexpressing peroxiredoxin 6 show increased resistance to lung injury in hyperoxia. 1639 55

Muscular exercise results in an increased production of free radicals and other forms of reactive oxygen species (ROS). Further, developing evidence implicates cytotoxins as an underlying etiology of exercise-induced stimuli in muscle redox status, which could result in muscle fatigue and/or injury. Two major classes of endogenous protective mechanisms (enzymatic and nonenzymatic antioxidants) work together to reduce the harmful effects of oxidants in the cell. This study examined the effects of acute physical exercise on the enzymatic antioxidant systems of different athletes and comparison was made to the mechanism of action of three main antioxidant enzymes in the blood. Handball players (n = 6), water-polo players (n = 20), hockey players (n = 22), basketball players (n = 24), and a sedentary control group (n = 10 female and n = 9 male) served as the subjects of this study. The athletes were divided into two groups according to the observed changes of activity of superoxide dismutase enzyme. The antioxidant enzyme systems were characterized by catalase (CAT), glutathione-peroxidase (GPX), and superoxide-dismutase (SOD) and measured by spectrophotometry. An important finding in the present investigation is that when the activities of SOD increased, the activities of GPX and CAT increased also and this finding related to the physical status of interval-trained athletes. Positive correlation between SOD and GPX activities was observed (r = 0.38 females, r = 0.56 males; p < 0.05). We have observed that the changes in the primary antioxidant enzyme systems of athletes are sport specific, and different from control subjects. Presumably, with interval-trained athletes, hydrogen-peroxide is significantly eliminated by glutathione-peroxidase. From these results it can be concluded that the blood redox status should be taken into consideration when establishing a fitness level for individual athletes.
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PMID:Antioxidant status of interval-trained athletes in various sports. 1647 56

The effects of salicylic acid (SA) and cold on apoplastic protein levels and activities of apoplastic catalase (CAT), peroxidase (POX) and polyphenol oxidase (PPO) were investigated in winter wheat (Triticum aestivum cv. Dogu-88) leaves. The plants were grown with and without 10 microM SA treatment at both control (20/18 degrees C for 30 and 45-day) and cold (10/5 degrees C for 30-day and 5/3 degrees C for 45-day) acclimatisations. Molecular masses of the apoplastic polypeptides were shown ranging in size from 20 to 66 kDa on SDS-PAGE. Accumulation and pattern of the polypeptides were changed by both SA and cold. It is observed that CAT, POX and PPO activities at 45-day control leaves were higher than at 30-day. When the activities with SA and cold treatments are compared to their controls, CAT activities were decreased while POX and PPO activities were increased by both the treatments. When the activities with cold+SA treatment are compared to their cold treatments, CAT and POX activities were decreased while PPO activity was increased by SA. It is concluded that exogenous SA can be involved in cold tolerance by regulating apoplastic proteins and antioxidant enzyme activities.
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PMID:Effects of salicylic acid and cold treatments on protein levels and on the activities of antioxidant enzymes in the apoplast of winter wheat leaves. 1651 11

Aquatic organisms are exposed to a variety of natural chemical stressors such as humic substances. The aim of this study was to investigate the mode of action of natural organic matter (NOM, roughly 80% of which is humic substances) on two freshwater amphipods from Lake Baikal, Eulimnogammarus verrucosus (Gerstf.) and Eulimnogammarus cyaneus (Dyb.), in order to assess the potential oxidative stress of NOM impact. Chosen as oxidative stress markers were lipid peroxidation and cell internal hydrogen peroxide level as well as peroxidase, catalase, and glutathione S-transferase activities. Exposure of amphipods to NOM caused a significant increase in lipid peroxidation but a concomitant decrease in hydrogen peroxide concentration, and peroxidase and (to a lesser degree) glutathione S-transferase activities. An interim increase of catalase activity was observed. A possible reason for the decrease in major antioxidant enzyme activity is exhaustion of the reservoir of reduced substrates in the first stage of the antioxidant defense reaction. Despite the inhibition of major antioxidant enzymes, the studied amphipods were able to successfully resist the NOM oxidative impact and, at low NOM concentrations, to combat lipid peroxidation processes.
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PMID:Specific antioxidant reactions to oxidative stress promoted by natural organic matter in two amphipod species from Lake Baikal. 1652 84

Biochemical responses to joint stress of chlorimuron-ethyl and cadmium (Cd) in wheat Triticum aestivum were examined. The joint action of chlorimuron-ethyl and Cd weakened the inhibition of Cd or chlorimuron-ethyl on the formation of chlorophyll. It was deduced that wheat plants had the capability to protect themselves by increasing the activity of the antioxidant enzyme peroxidase (POD) with the exposure time. The joint effect of chlorimuron-ethyl and Cd on the superoxide dismutase (SOD) activity in leaves was additive, while the joint effect on the SOD activity in roots was determined by the interaction of chlorimuron-ethyl and Cd in wheat. It was also concluded that the change of malondialdehyde (MDA) content in wheat might not be a good biomarker in the oxidative damage by chlorimuron-ethyl, while a decrease in the soluble protein content and POD activity in roots could be considered as a biomarker in the damage of wheat by chlorimuron-ethyl and Cd.
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PMID:Joint stress of chlorimuron-ethyl and cadmium on wheat Triticum aestivum at biochemical levels. 1653 Mar 9

Thioredoxin reductase and thioredoxin constitute the cellular thioredoxin system, which provides reducing equivalents to numerous intracellular target disulfides. Mammalian thioredoxin reductase contains the rare amino acid selenocysteine. Known as the "21st" amino acid, selenocysteine is inserted into proteins by recoding UGA stop codons. Some model eukaryotic organisms lack the ability to insert selenocysteine, and prokaryotes have a recoding apparatus different from that of eukaryotes, thus making heterologous expression of mammalian selenoproteins difficult. Here, we present a semisynthetic method for preparing mammalian thioredoxin reductase. This method produces the first 487 amino acids of mouse thioredoxin reductase-3 as an intein fusion protein in Escherichia coli cells. The missing C-terminal tripeptide containing selenocysteine is then ligated to the thioester-tagged protein by expressed protein ligation. The semisynthetic version of thioredoxin reductase that we produce in this manner has k(cat) values ranging from 1500 to 2220 min(-)(1) toward thioredoxin and has strong peroxidase activity, indicating a functional form of the enzyme. We produced the semisynthetic thioredoxin reductase with a total yield of 24 mg from 6 L of E. coli culture (4 mg/L). This method allows production of a fully functional, semisynthetic selenoenzyme that is amenable to structure-function studies. A second semisynthetic system is also reported that makes use of peptide complementation to produce a partially active enzyme. The results of our peptide complementation studies reveal that a tetrapeptide that cannot ligate to the enzyme (Ac-Gly-Cys-Sec-Gly) can form a noncovalent complex with the truncated enzyme to form a weak complex. This noncovalent peptide-enzyme complex has 350-500-fold lower activity than the semisynthetic enzyme produced by peptide ligation.
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PMID:Semisynthesis and characterization of mammalian thioredoxin reductase. 1661 5

The anti-diabetic and antioxidative effect of amaranth grain (AG) and its oil fraction (AO) was studied in streptozotocin-induced diabetic rats. Male Sprague-Dawley rats were divided into four groups after induction of STZ-diabetes: normal control; diabetic control; diabetic-AG supplement (500 g kg(-1) diet); diabetic-AO supplement (100 g kg(-1) diet) and fed experimental diets for 3 weeks. Serum glucose, insulin, activities of serum marker enzymes of liver function and liver cytosolic antioxidant enzymes were measured. The AG and AO supplement significantly decreased the serum glucose and increased serum insulin level in diabetic rats. Serum concentration of liver function marker enzymes, GOT and GPT, were also normalized by AG and AO treatment in diabetic rats. Liver cytosolic SOD and GSH-reductase activities were significantly increased, and catalase, peroxidase and GSH-Px activities were decreased in diabetic rats. AG and AO supplement reverted the antioxidant enzyme activities to near normal values. Hepatic lipid peroxide product was significantly higher, and GSH content was decreased in diabetic rats. However, AG and AO supplement normalized these values. Our data suggest that AG and AO supplement, as an antioxidant therapy, may be beneficial for correcting hyperglycaemia and preventing diabetic complications.
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PMID:Antioxidative and anti-diabetic effects of amaranth (Amaranthus esculantus) in streptozotocin-induced diabetic rats. 1663 92


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