Superoxide dismutase activity in nematodes

The activities of the enzymes superoxide dismutase (E.C.:1.15.1.1) and catalase (E.C.:1.11.1.6) were studied in purified extracts of four nematodes: Ascaris suum, Toxascaris leonina, Toxocara canis and T. cati adult males and females. No catalase activity was found in any of the extracts. The results reveal that the SOD activities of the four parasites presented species differences and also sexual differences within each species. Polyacrylamide gel electrophoresis pattern analysis confirmed that the mobilities, widths and band intensities varied according to the species and sex of the parasite from which the enzyme was obtained.     

Changes in antioxidative enzymes in cucumber cotyledons during natural senescence: comparison with those during dark-induced senescence

Changes in 7 antioxidative enzymes in naturally senescent cotyledons of cucumber ( Cucumis sativus ) were investigated. The activities of superoxide dismutase (SOD; EC 1.15.1.1), catalase (EC 1.11.1.6), dehydroascorbate reductase (EC 1.8.5.1) and glutathione reductase (GR; EC 1.6.4.2) gradually decreased during the progression of senescence, while those of ascorbate peroxidase (APX; EC 1.11.1.11) and guaiacol peroxidase (GPX; EC 1.11.1.7) gradually increased. The activity of monodehydroascorbate reductase (MDAR; EC 1.6.5.4) was not significantly changed. Western blot analysis showed that the protein level of mitochondrial SOD gradually declined. The protein level of catalase transiently decreased and then increased in the later stages of senescence, despite the decrease in its activity. The overall behavior was markedly different from that found in cotyledons of artificially senescing seedlings transferred into darkness; the activities of SOD, catalase, APX, GPX and GR gradually increased.     

Superoxide,hydrogen peroxide,and the gelling of phloem sap from Cucurbita pepo

The possible involvement of superoxide and hydrogen peroxide in the oxidative gelling of phloem exudate from Cucurbita pepo. was investigated. Neither superoxide dismutase (EC 1.15.1.1) nor catalase (EC 1.11.1.6) inhibited the reaction. Although catalase could not be detected in exudate, both peroxidase (EC. 1.11.1.7) and superoxide dismutase were present in reasonable amounts. Polyacrylamide gel electrophoresis revealed one major and one minor isozyme of superoxide dismutase, both of which were adjudged to contain copper and zinc as their prosthetic metals, on the basis of cyanide inhibition and molecular weight.Abbreviations SOD superoxide dismutase     

Superoxide dismutase biosynthesis by two thermophilic bacteria

Some high-molecular weight antioxidant defense system components of two thermophilic bacteria isolated from spa waters of Serbia (Yugoslavia) and identified as Bacillus stearothermophilus and Thermothrix sp. were studied. In addition to superoxide dismutase (SOD; EC 1.15.1.1), qualitative analyses demonstrated the presence of catalase (EC 1.11.1.6), peroxidases and oxidases in both bacterial strains. Cell-free extracts were subjected to nondenaturing polyacrylamide gel electrophoresis (PAGE) and SOD activity in the eluates of the corresponding bands was examined in the presence of several specific inhibitors. A slight decrease of SOD activity observed in the presence of 0.3 M potassium cyanide and its complete insensitivity to hydrogen peroxide (5 mM) and sodium azide (20 mM) action suggest that the enzyme occurring in the two thermophiles represents Mn SOD. A high SOD activity recorded in cell-free extracts strongly recommends these two bacterial strains as potential producers of this important antioxidant defense system component at industrial scale.     

Distribution of superoxide dismutase and glutathione peroxidase in the carp: erythrocyte manganese SOD.

A non copper containing superoxide dismutase (Cu-SOD), presumably manganese superoxide dismutase (Mn-SOD), has been identified in carp erythrocytes. Erythrocyte catalase is low, glutathione peroxidase (GPX) is extremely high, and superoxide dismutase (SOD) is relatively low. The distribution of Cu-SOD, Mn-SOD and glutathione peroxidase in various tissues is described. Highest activities of both enzymes are found in the liver and lowest in white muscle and the swim bladder.     

Drosophila melanogaster larvae fed by glucose and fructose demonstrate difference in oxidative stress markers and antioxidant enzymes of adult flies

Activities of antioxidant and associated enzymes, and oxidative stress markers were assessed in newly enclosed adult fruit flies Drosophila melanogaster developed on diets with 4 and 10% glucose or fructose. In fly males, 10% fructose promoted higher content of protein carbonyls and catalase activity, but lower superoxide dismutase (SOD) activity than 4%, while in females-lower levels of high molecular mass thiols (H-SH). Females at all diets had virtually the same level of lipid peroxides, low-molecular-mass thiols, catalase, and superoxide dismutase activities. Fed with 4% fructose and glucose males demonstrated 24 and 26% lower H-SH level than females, respectively. On diets with 4% glucose, 10% glucose and fructose females had 32, 26 and 27% lower catalase activity than respective males, and 1.3-1.5-fold lower glucose-6-phosphate dehydrogenase activity on glucose-containing diets. Strong positive correlations between H-SH level and G6PD activity, as well as between catalase and G6PDH activity were found. These results suggest that type and concentration of dietary carbohydrate affect antioxidant defense in fruit flies. It also substantially depends on fly sex, comprising presumably levels of protein carbonyls and lipid peroxides, as well as catalase and SOD activities in males and G6PDH activity in females.     

Influence of Brassinosteroids on Antioxidant Enzymes Activity in Tomato Under Different Temperatures

The effect of brassinosteroids (BRs) on catalase (EC 1.11.1.6), peroxidase (EC 1.11.1.7) and superoxide dismutase (SOD, EC 1.15.1.1) activity in tomato leaf discs was analyzed at 25 and 40 °C. Tomato leaf discs were preincubated for 24 h in Petri dishes with 24-epibrassinolide (EBR) or a polyhydroxylated spirostanic analogue of brassinosteroids (MH5). Both concentrations (10.60 and 2.12 nM) of EBR and MH5 stimulated the activity of SOD at 25 and 40 °C, the MH5-stimulated increase of this enzyme activity was greater. Peroxidase activity was unaffected at 25 °C, while at 40 °C this activity was enhanced by both compounds. The changes in catalase activity markedly depended on the structure BRs, doses and temperature. The results suggest a possible role of EBR and MH5 in the reduction of cell damage produced by heat stress due to induction of enzymatic antioxidants.     

Antioxidative enzymes in seedlings of Nelumbo nucifera germinated under water

Dry seeds of anoxia-tolerant lotus ( Nelumbo nucifera Gaertn= Nelumbium speciosum Willd.) have green shoots with plastids containing chlorophyll, so photosynthesis starts even in seedlings germinated under water, namely hypoxia. Here we investigated antioxidative enzyme changes in N. nucifera seedlings responding to oxygen deficiency. The activity of superoxide dismutase (SOD; EC 1.15.1.1), dehydroascorbate reductase (DHAR; EC 1.8.5.1) and glutathione reductase (GR; EC 1.6.4.2) were lower in seedlings germinated under water (submerged condition) in darkness (SD seedlings) than those found in seedlings germinated in air and darkness (AD seedlings). In contrast, ascorbate peroxidase (APX; EC 1.11.1.11) activity was higher in SD seedlings and the activity of catalase (EC 1.11.1.6) and monodehydroascorbate reductase (MDAR; EC 1.6.5.4) in SD seedlings was nearly the same as in AD seedlings. When SD seedlings were exposed to air, the activity of SOD, DHAR and GR increased, while the activity of catalase and MDAR decreased. Seven electrophoretically distinct SOD isozymes were detectable in N. nucifera . The levels of plastidic Cu,Zn-SODs and Fe-SOD in SD seedlings were comparable with those found in AD seedlings, which may reflect the maintenance of green plastids in SD seedlings as well as in AD seedlings. These results were substantially different from those previously found in rice seedlings germinated under water.     

The activity of antioxidant defence enzymes in the mussel Mytilus galloprovincialis from the Adriatic Sea

The activity of the antioxidant defence enzymes superoxide dismutase (SOD, EC 1.15.1.1), catalase (CAT, EC 1.11.1.6), glutathione peroxidase (GSH-Px, EC 1.11.1.9), glutathione reductase (GR, EC 1.6.4.2) and the phase II biotransformation enzyme glutathione-S-transferase (GST, EC 2.5.1.18) in whole mussels (Mytilus galloprovincialis) were studied. The mussels were collected in winter and in spring at two localities in the Adriatic Sea: Bar Port and Tivat Bay. Our results show that the activities of SOD, GSH-Px and GST were seasonally dependent with higher activities in winter. GR activity was also higher in winter, but only in mussels from Bar Port. In mussels from Tivat Bay, GR activity was lower in winter compared to spring. In addition, a decrease in CAT activity in mussels from Bar Port compared to those from Tivat Bay was found. It can be concluded that seasonal variations should be incorporated into interpretation of biomonitoring studies in mussels.     

Superoxide dismutase, catalase and peroxidase in four strains of Neisseria meningitidis of different virulence

Abstract The effects of growth media on superoxide dismutase (SOD), catalase and peroxidase were compared in cell-free extracts from four strains of Neisseria meningitidis . The highly virulent strains, DRES-14 and M-1011, were consistently higher in SOD and catalase than the less virulent strains, DRES-03 and DRES-04. Cells grown in brain-heart infusion medium contained the highest levels of catalase. N. meningitidis contained one electrophoretic SOD band which was identified as iron-containing SOD (FeSOD). It was also shown that the presence of catalase could yield an artifactual SOD-band when the SOD activity stain is performed in the presence of 10 mM H₂O₂, normally required to inactivate and identify FeSODs.     

Extracellular superoxide dismutase in vessels and airways of humans and baboons

Extracellular superoxide dismutase (EC SOD) is generally the least abundant SOD isozyme in tissues, while the intracellular Cu,Zn SOD is usually the most abundant isozyme. The biological significance of EC SOD is unknown. Immunolocalization studies show that EC SOD is in the connective tissue surrounding smooth muscle in vessels and airways within the lung. Endothelium derived relaxing factor, thought to be a nitric oxide (NO^·) species, is a primary mediator of vascular relaxation. During NO^·′ diffusion between the endothelium and smooth muscle, extracellular superoxide would be the most efficient scavenger of NO^·. High levels of extracellualar superoxide dismutase in vessels could, therefore, be essential to enable NO' to modulate vascular tone. To evaluate the hypothesis that vessel walls are functionally rich in extracellular superoxide scavenging capacity, this study quantitates the EC SOD levels in pulmonary and systemic vessels and in airways. Both pulmonary and systemic arteries in humans and baboons were found to contain high activities of EC SOD. The level of EC SOD in all human and baboon arteries examined is greater than or equal to the level of intracellular Cu,Zn SOD, and EC SOD accounted for over 70% of the total SOD activity in some vessels examined. Immunolocalization of EC SOD in human and baboon vessels show similar distributions of this enzyme in pulmonary and systemic vessels. EC SOD is located beneath the endothelium, surrounding smooth muscle cells, and throughout the adventitia of vessels. The high level of EC SOD in vessels, and its localization between endothelial and smooth muscle cells, suggest that regulation of superoxide may be particularly important in this region, possibly in regulating vascular tone.     

反枝苋水浸提液与挥发油对黄瓜根尖的影响

采用悬空气法研究了在入侵植物反枝苋(Amaranthus retroflexus L.)水浸提液和挥发油作用下,黄瓜根缘细胞活性、根冠果胶甲基酯酶(PME)、根尖过氧化氢酶(CAT)、过氧化物酶(POD)、超氧化物歧化酶(SOD)以及丙二醛(MDA)含量的变化规律.结果表明:反枝苋水浸提液对黄瓜根的生长无显著性影响而挥发油显著抑制黄瓜根的生长,且随浓度增大抑制作用显著增强.PME活性随着水浸提液浓度的增大呈先上升后下降趋势,而随着挥发油浓度的升高呈现逐渐上升的趋势;水浸提液和挥发油均降低了对根缘细胞的存活率,这种抑制作用随浓度的增加而增大;随着处理液浓度增大,黄瓜根尖中MDA含量、CAT活性整体表现为增加,SOD活性先升高后降低,POD活性与对照差异不显著.反枝苋挥发油的化感效应大于水浸提液的化感效应.     

Alterations in aortic antioxidant components in an experimental model of atherosclerosis: A time-course study

Antioxidant component alterations in the aorta during atherogenesis were examined in atherosclerosis-susceptible (SUS) Japanese quail fed a cholesterol-supplemented (0.5% w/w) diet. Birds fed a non-supplemented diet provided information on the effects of aging on endogenous antioxidants. One hundred adult SUS males were used. Birds were sacrificed after 0, 4, 8 and 12 weeks on the diets and were examined for plaque development and corresponding antioxidant component alterations in aorta and myocardium. With aging, superoxide dismutase (SOD) activity was increased in both tissues, whereas aortic glutathione peroxidase (GPx) activity and myocardial glutathione reductase (GRd) activity decreased. Myocardial ascorbate levels increased with aging, with a reciprocal decrease in myocardial tocopherol levels. Following 4 weeks of cholesterol supplementation, aortic GRd decreased, SOD activity increased, but activities of GPx and catalase were unchanged. This same qualitative pattern of antioxidant enzyme changes was also found in myocardium. Thus, although aortic antioxidant enzyme changes produced by cholesterol feeding and aging showed some similarities, the early phase of atherogenesis does not simply reflect accelerated aging. In the late stages of atherogenesis, SOD activity returned to baseline, but other antioxidant enzymes remained unaltered from levels characterizing the early phase of lesion development. There was no detectable functional coupling between changes in GPx and GRd, nor between SOD (which produces hydrogen peroxide) and GPx or catalase (which utilize hydrogen peroxide as substrate). Previously reported alterations in erythrocyte antioxidant enzyme components during atherogenesis in quail were not predictive of changes in the corresponding enzymes in the aorta and myocardium.     

Identification of superoxide dismutase isoenzymes in tobacco pollen

We investigated the possible existence of superoxide dismutase (SOD; EC 1.15.1.1) isoenzymes in the pollen of Nicotiana tabacum (Petit Havana SR-1 cultivar). To detect SOD activity, crude extracts from tobacco pollen were subjected to native polyacrylamide gel electrophoresis followed by staining with nitroblue tetra-zolium (NBT). The presence of six SOD isoenzymes was detected in tobacco pollen. Treatment with SOD inhibitors indicated the presence of one manganese SOD (Mn SOD), five copper-zinc SOD (Cu/Zn SOD) isoenzymes, and the absence of iron SOD (Fe SOD).     

Species-specific heterogeneity for molecular weight estimates of serum extracellular superoxide dismutase activities.

1. Several apparent molecular weights (mol. wt) are reported for plasma or serum extracellular superoxide dismutase (EC SOD) activity. This study found species-dependent heterogeneity for apparent mol. wt using gel filtration with Sephadex G-150. 2. EC SOD activity in rabbit and guinea-pig serum, measured by a modified pyrogallol assay, eluted just before ceruloplasmin activity, but rat and bovine serum activity eluted after ceruloplasmin (apparent mol. wt of 142,000 and 73,000, respectively). 3. The heterogeneity between rat and rabbit serum was not eliminated by substituting a cytochrome-c-based SOD assay for the pyrogallol method, by substituting lung extracts for serum, by analysing a mixture of rat and rabbit serums, nor by analysing hemolysed serum. The apparent mol. wt of bovine serum EC SOD activity was not duplicated by gel filtration analysis of a mixture of bovine cytosolic SOD and albumin. 4. In conclusion, species-specific variation in apparent mol. wt for serum EC SOD activity was demonstrated under several circumstances.     

Astrocytes enhance radical defence in capillary endothelial cells constituting the blood-brain barrier.

Astrocytes (AC) induce blood-brain barrier (BBB) properties in brain endothelial cells (EC). As antioxidative activity (AOA) is assumed to be a BBB characteristic, we tested whether AC improve AOA of EC. Monocultivated AC showed higher AOA [manganese superoxide dismutase (SOD), catalase (Cat), glutathione peroxidase (GPx)] than EC. Cocultivation elevated AOA in EC (MnSOD, CuZnSOD, Cat, GPx), and AC (MnSOD, CuZnSOD, GPx). Hypoxia increased radical-induced membrane lipid peroxidation in monocultivated, but not in cocultivated EC. Thus, EC/AC cocultivation intensifies AOA in both cell types, protects the EC, and therefore, the BBB against oxidative stress. The high AOA is regarded as an essential property of the BBB, which is induced by AC.     

Coisolation of glutathione peroxidase, catalase and superoxide dismutase from human erythrocytes

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.     

淡水三角涡虫不同发育时期三种抗氧化酶的研究

以鲁中山地区的淡水三角涡虫卵囊、幼虫、成虫为材料,研究了涡虫在不同发育过程中3种抗氧化酶SOD、CAT、GSH-Px的活性变化.结果 表明,SOD在发育初期活性增长迅速,在幼虫孵出后活性略减,最后趋于稳定;CAT活性在卵囊阶段活性较低,从幼虫孵出后活性增长很快,并在成体中保持较高的活性;GSH-Px活性在卵囊时期活性较高,从幼虫孵出后活性降低,在成体中活性较低.     

Effect of copper excess on superoxide dismutase,catalase, and peroxidase activities in sunflower seedlings (<Emphasis Type="Italic">Helianthus annuus</Emphasis> L.)

The changes in lipid peroxidation, antioxidative and lignifying enzyme activities were studied in leaves and stems of Cu-stressed sunflower seedlings. In both organs, membrane lipid peroxidation was enhanced by copper treatment. Additionally, catalase (EC 1.11.1.6) and superoxide dismutase (EC 1.15.1.1) activities were modulated: The activity of superoxide dismutase was enhanced in both plant organs. Differently, catalase activity was not affected in leaves but significantly reduced in stems. Peroxidase (EC 1.11.1.7) activities were also changed. Guaiacol peroxidase activity was increased in leaves and stems. In the same way, electrophoretic analysis of the anionic isoperoxidases involved in lignification (syringaldazine peroxidase) revealed qualitative and quantitative changes on the isoenzyme patterns. These modifications were accompanied by the increase of the NADH-oxidase activity in ionically cell wall bound fraction. It appeared that the growth delay caused by copper excess could be related to the activation of lignifying peroxidases.