The D-amino acid oxidase of molds.
Explore the source record for details and available documents.
Amino Acids↗
SEARCH · Search PubMed
Results for “OXIDASE AND PEROXIDASE”
Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.
Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.
Changes in the ascorbate metabolism of apoplastic and symplastic spaces are associated with cell differentiation.
Ascorbate levels and redox state, as well as the activities of the ascorbate related enzymes, have been analysed both in the apoplastic and symplastic spaces of etiolated pea (Pisum sativum L.) shoots during cellular differentiation. The ascorbate pool and the ascorbate oxidizing enzymes, namely ascorbate oxidase and ascorbate peroxidase, were present in both pea apoplast and symplast, whereas ascorbate free radical reductase and dehydroascorbate reductase were only present in the symplastic fractions. During cell differentiation the ascorbate redox enzymes changed in different ways, since a decrease in ascorbate levels, ascorbate peroxidase and ascorbate free radical reductase occurred from meristematic to differentiated cells, whereas ascorbate oxidase and dehydroascorbate reductase increased. The activity of secretory peroxidases has also been followed in the apoplast of meristematic and differentiating cells. These peroxidases increased their activity during differentiation. This behaviour was accompanied by changes in their isoenzymatic profiles. The analysis of the kinetic characteristics of the different peroxidases present in the apoplast suggests that the presence of ascorbate and ascorbate peroxidase in the cell wall could play a critical role in regulating the wall stiffening process during cell differentiation by interfering with the activity of secretory peroxidases.
Ascorbate Oxidase↗
Development of a peroxidase-coupled fluorometric assay for lysyl oxidase.
Explore the source record for details and available documents.
Amines↗
Enzymes Involved in Defense Functions of Hemocytes of Mussel Mytilus galloprovincialis
Mytilus galloprovincialis hemocytes contain phosphatases, esterases, proteases, and glucosidases as revealed by a semiquantitative colorimetric method. The activity levels of some enzymes changed throughout the months of the experiment without a seasonal pattern. No differences in the enzyme levels were found between the two groups of mussels of different age (cultivated 11 and 19 months on ropes hung from the same raft). Light microscopy study of hemocyte enzymes showed that hyalinocytes and granulocytes had reaction of acid phosphatase, beta-glucuronidase, alpha-naphthyl butyrate esterase, naphthol AS-D chloroacetate esterase, and alpha-naphthyl acetate esterase. Phenoloxidase and peroxidase activities were also detected in monolayers of hemocytes. Ultrastructural study revealed that the granules of hemocytes contained acid phosphatase, beta-glucuronidase, nonspecific esterases, peroxidase, and NADH oxidase. Products of beta-glucuronidase and peroxidase reaction were also localized in the plasma membrane. Lysozyme activity level was higher in hemocytes than in serum. Comparison between the two groups of different age showed a higher activity level of lysozyme in younger mussels.
Journal Article↗
Apoplastic Peroxidases and Lignification in Needles of Norway Spruce (Picea abies L.).
The objective of the present study was to investigate the correlation of soluble apoplastic peroxidase activity with lignification in needles of field-grown Norway spruce (Picea abies L.) trees. Apoplastic peroxidases (EC 1.11.1.7) were obtained by vacuum infiltration of needles. The lignin content of isolated cell walls was determined by the acetyl bromide method. Accumulation of lignin and seasonal variations of apoplastic peroxidase activities were studied in the first year of needle development. The major phase of lignification started after bud break and was terminated about 4 weeks later. This phase correlated with a transient increase in apoplastic guaiacol and coniferyl alcohol peroxidase activity. NADH oxidase activity, which is thought to sustain peroxidase activity by production of H2O2, peaked sharply after bud break and decreased during the lignification period. Histochemical localization of peroxidase with guaiacol indicated that high activities were present in lignifying cell walls. In mature needles, lignin was localized in walls of most needle tissues including mesophyll cells, and corresponded to 80 to 130 [mu]mol lignin monomers/g needle dry weight. Isoelectric focusing of apoplastic washing fluids and activity staining with guaiacol showed the presence of strongly alkaline peroxidases (isoelectric point [greater than or equal to] 9) in all developmental stages investigated. New isozymes with isoelectric points of 7.1 and 8.1 appeared during the major phase of lignification. These isozymes disappeared after lignification was terminated. A strong increase in peroxidase activity in autumn was associated with the appearance of acidic peroxidases (isoelectric point [less than or equal to] 3). These results suggest that soluble alkaline apoplastic peroxidases participate in lignin formation. Soluble acidic apoplastic peroxidases were apparently unrelated to developmentally regulated lignification in spruce needles.
Journal Article↗
[Inhibition of the autoxidation of polyunsaturated fatty acids by superoxide dismutase].
In this comprehensive approach, inhibition of autoxidation of PUFA by SOD or other enzymes has been studied. The systems used were: 1) in miscible media in which enzyme, substrat, and peroxidation products are soluble; 2) in non-miscible media such as emulsions; 3) in heterogenous media containing subcellular fragments or whole blended tissue. Depending on experimental conditions, inhibition or activation of peroxidation by SOD can be observed in miscible systems. Other enzymes such as phospholipase A, xanthine oxidase, or horseradish peroxidase are protective in heterogeneous media. Moreover, PUFA hydroperoxide are scavenged by glutathione peroxidase which thus could lessen the autocatalytic effects encountered during peroxidation. Enzymatic inhibition of autoxidation in emulsions was not observed. We conclude that superoxide ion does not play a major role in the initiation of peroxidation and that it may very well act as a free radical chain terminator. In addition, other enzymes such as xanthine oxidase, horseradish peroxidase or phospholipase A show an effective although empirical protection against autoxidation in homogenates of tissues.
Fatty Acids, Unsaturated↗
Characterization of oxidative enzyme changes in buffalograsses challenged by Blissus occiduus.
This research investigated the role of oxidative enzymes in the defense response of buffalograss, Buchloë dactyloides (Nuttall) Engelmann, to Blissus occiduus Barber. Changes in catalase and peroxidase activity were observed in both resistant and susceptible buffalograsses in response to chinch bug feeding. Susceptible plants were shown to have a lower level of catalase activity compared with their respective control plants. By contrast, catalase activities of resistant plants were similar between infested and control buffalograsses throughout the study. Resistant plants had higher levels of peroxidase activity compared with their control plants, whereas peroxidase activities for control and infested susceptible plants remained at similar levels or were slightly lower for infested plants. These findings suggest that chinch bug feeding leads to a loss in catalase activity in susceptible buffalograsses. In contrast, resistant buffalograsses may be able to tolerate chinch bug feeding by increasing their peroxidase activity. Polyphenol oxidase activities were similar between control and infested plants for the buffalograsses evaluated. Among the enzymes examined, no differences in isozyme profiles for peroxidase and polyphenol oxidase were detected between control and infested 378, NE91-118, Cody, and Tatanka plants. Gels stained for catalase identified differences in the isozyme profiles of infested and uninfested 378 plants; however, infested and control NE91-118, Tatanka, and Cody plants has similar isozyme profiles. No differences in protein profiles were observed between chinch buginfested 378, NE91-118, Cody, and Tatanka plants and their respective uninfested controls.
Animals↗
Protein-sulfenic acids: diverse roles for an unlikely player in enzyme catalysis and redox regulation.
While it has been known for more than 20 years that unusually stable cysteine-sulfenic acid (Cys-SOH) derivatives can be introduced in selected proteins by mild oxidation, only recently have chemical and crystallographic evidence for functional Cys-SOH been presented with native proteins such as NADH peroxidase and NADH oxidase, nitrile hydratase, and the hORF6 and AhpC peroxiredoxins. In addition, Cys-SOH forms of protein tyrosine phosphatases and glutathione reductase have been suggested to play key roles in the reversible inhibition of these enzymes during tyrosine phosphorylation-dependent signal transduction events and nitrosative stress, respectively. Substantial chemical data have also been presented which implicate Cys-SOH in redox regulation of transcription factors such as Fos and Jun (activator protein-1) and bovine papillomavirus-1 E2 protein. Functionally, the Cys-SOHs in NADH peroxidase, NADH oxidase, and the peroxiredoxins serve as either catalytically essential redox centers or transient intermediates during peroxide reduction. In nitrile hydratase, the active-site Cys-SOH functions in both iron coordination and NO binding but does not play any catalytic redox role. In Fos and Jun and the E2 protein, on the other hand, a key Cys-SH serves as a sensor for intracellular redox status; reversible oxidation to Cys-SOH as proposed inhibits the corresponding DNA binding activity. These functional Cys-SOHs have roles in diverse cellular processes, including signal transduction, oxygen metabolism and the oxidative stress response, and transcriptional regulation, as well as in the industrial production of acrylamide, and their detailed analyses are beginning to provide the chemical foundation necessary for understanding protein-SOH stabilization and function.
Animals↗
Phenol contents, oxidase activities, and the resistance of coffee to the leaf miner Leucoptera coffeella.
We examined the role of phenolic compounds, and the enzymes peroxidase and polyphenol oxidase, in the expression of resistance of coffee plants to Leucoptera coffeella (Lepidoptera: Lyonetiidae). The concentrations of total soluble phenols and chlorogenic acid (5-caffeoylquinic acid), and the activities of the oxidative enzymes peroxidase (POD) and polyphenol oxidase (PPO), were estimated in leaves of Coffea arabica, C. racemosa, and progenies of crosses between these species, which have different levels of resistance, before and after attack by this insect. The results indicate that phenols do not play a central role in resistance to the coffee leaf miner. Differences were detected between the parental species in terms of total soluble phenol concentrations and activities of the oxidative enzymes. However, resistant and susceptible hybrid plants did not differ in any of these characteristics. Significant induction of chlorogenic acid and PPO was only found in C. racemosa, the parental donator of the resistance genes against L. coffeella. High-performance liquid chromatography (HPLC) analysis also showed qualitative similarity between hybrids and the susceptible C. arabica. These results suggest that the phenolic content and activities of POD and PPO in response to the attack by the leaf miner may not be a strong evidence of their participation in direct defensive mechanisms.
Animals↗
Antitumor activity of an immobilized peroxidase system against murine Ehrlich ascites is mediated by the immune system.
Earlier studies have shown that a mixture of glucose oxidase and a peroxidase exerts a tumoricidal effect on rats bearing Novikoff hepatomas when the enzyme mixture is injected intraperitoneally. The enzyme mixture was shown to be nontoxic when injected into healthy animals at levels up to 600 times the therapeutic dose. In the present study, we have evaluated the possibility that the host immune defense system may be involved in the antitumor activity of the peroxidase system, using the murine Ehrlich ascites tumor as the target. The results revealed that the antitumor activity of the peroxidase system is absent in tumor-bearing animals whose immune system has been compromised by whole body gamma-irradiation or by an induced selenium deficiency. The peroxidase system was also found to be inactive in tumor-bearing mice whose immune system was suppressed by the administration of cyclosporin A as well as in athymic (nu/nu) mice. These results indicate that T lymphocytes may directly or indirectly be involved in the in vivo antitumor activity of the peroxidase system. This could explain the observed high selectivity toward tumor cells by the enzyme system in vivo and its lack of toxicity in healthy animals.
Animals↗
The inhibition of peroxidase and indole-3-acetic acid oxidase activity by British Anti-Lewisite.
Explore the source record for details and available documents.
Alcohol Oxidoreductases↗
Effects of metsulfuron-methyl on the microbial population and enzyme activities in wheat rhizosphere soil.
The effects of metsulfuron-methyl, a sulfonylurea herbicide, on the wheat soil microorganisms were evaluated by the methods of microbial inoculation culture, and the activities of three enzymes were measured using the colorimetric method. The tolerant microorganisms that can resist 500 microg x g(-1) metsulfuron-methyl in the counting culture medium were studied specially. Metsulfuron-methyl distinctly inhibited the common aerobic heterotriphic bacteria, but the effects on common fungi and common actinomycete were not evident. In the meantime, the number of tolerant fungi increased greatly in the rhizosphere after the application of metsulfuron-methyl in contrast to the significant decrease of the amount of tolerant actinomycete. It indicates that fungi might turn into the dominant microbial type and actinomycete is the sensitive factor in the soil polluted by sulfonylurea residues. The population of aromatic compounds-decomposing bacteria, aerobic azotobacter, and nitrite bacteria all increased in the earlier period, but the aerobic azotobacter decreased rapidly in number 30 days later, and the amount of nitrite bacteria also showed a temporary decrease with time 15 days later. However, the denitrifying bacteria just began to increase significantly after the crops had grown for 50 days. The amount of sulfur-oxidizing bacteria gradually decreased with the growth of crops, and so were the sulfate-reducing bacteria after metsulfuron-methyl application. To all types of microorganisms, there were more microbes in rhizosphere samples than those in nonrhizosphere except aerobic azotobacter. It means the growth of wheat root system can stimulate the growth of most microorganisms. The activities of hydrogen peroxidase and polyphenol oxidase in soil samples after metsulfuron-methyl application were notably lower than those in the control, and the difference of the activities between the samples of rhizosphere and nonrhizosphere was evident. On the contrary, the activity of dehydrogenase was not inhibited by the application of metsulfuron-methyl, and the rhizosphere effect was not obvious either.
Actinobacteria↗
Wound-induced ethylene synthesis and expression and formation of 1-aminocyclopropane-1-carboxylate (ACC) synthase, ACC oxidase, phenylalanine ammonia-lyase, and peroxidase in wounded mesocarp tissue of Cucurbita maxima.
1-Aminocyclopropane-1-carboxylate (ACC) synthase was rapidly induced in mesocarp tissue of Cucurbita maxima after wounding in the cut surface layer in 1 mm thickness (ca. 9 cells) (first layer) in both the enzyme activity and the levels of transcript. This led to a rapid accumulation of ACC and hence ethylene production. In the inside tissue (1-2 mm) (second layer), no significant induction of ACC synthase was observed, which resulted in a low level of ACC, although ethylene was evolved at a much lower rate than the first one. In contrast to ACC synthase, ACC oxidase was induced markedly in both the first and second layers and the development of its activity and the levels of mRNA remained high until later stages. It was considered that wound ethylene was closely associated with the development of ACC oxidase, since 2,5-norbornadiene (NBD), an inhibitor of ethylene action, substantially suppressed it. Phenylalanine ammonia-lyase (PAL) greatly increased in activity after wounding similarly to that of ACC synthase, in which increase in PAL activity occurred predominantly in the first layer. Induction of peroxidase activity after wounding had a close correlation in profile with that of ACC oxidase in that marked increases in the activity were observed in both the first and second layers and were strongly suppressed by NBD application. Four peroxidase isozymes were found by PAGE, among which a fraction was newly detected after wounding.
Amino Acid Oxidoreductases↗
Decreased cytochrome c oxidase activity but unchanged superoxide dismutase and glutathione peroxidase activities in the spinal cords of patients with amyotrophic lateral sclerosis.
The cause of selective degeneration of motor neurons in the ventral horn of the spinal cord associated with amyotrophic lateral sclerosis (ALS) has still not been elucidated. Recently, so-called oxidative stress has been suggested to be a significant factor in the pathogenesis of this disease. We measured the antioxidant actions of superoxide dismutase (SOD), glutathione peroxidase (GSH-Px), and cytochrome c oxidase (CO) of the human spinal cord in patients with ALS in comparison with those in control patients. Total SOD activity in spinal cord transections from patients with sporadic ALS was not significantly different from the controls in ventral, lateral, or dorsal regions, although enzymic activity was relatively higher in the ventral compared with the dorsal region. GSH-Px activity in the spinal cord of ALS patients was not very different from that in the control tissue. In contrast, CO activity was significantly reduced in all three regions of the spinal cord in patients with ALS, although the reduction was more marked in the ventral region. These results suggest that reactive oxygen species may attack the mitochondrial respiratory chain, leading eventually to the degeneration of vulnerable motor neurons in the spinal cord, even though no obvious changes in the activity of antioxidant enzymes are detectable.
Adult↗
Involvement of peroxidase in chorion hardening in Aedes aegypti.
Peroxidase activity is detectable in Aedes aegypti ovaries, containing developing eggs, at 24 h following blood feeding, and peak peroxidase activity is reached at 36-48 h after the blood-meal. Peroxidase is associated with the chorion layer in mature eggs and the majority of the enzyme is released from the chorion layer by treating the isolated chorion fraction with SDS/urea. Analysis of the SDS/urea solubilized chorion proteins using SDS-PAGE with tropolone/H2O2 or dopa staining verified the presence of both peroxidase and phenol oxidase in the released chorion proteins. The molecular weight of chorion peroxidase is about 61,000 Da as determined by SDS-PAGE analysis. Incubation of the solubilized chorion proteins with tyrosine and H2O2 produces dityrosine, and hyrolysis of hardened egg chorion results in the detection of dityrosine and trityrosine in the chorion hydrolysate. Data suggest that chorion peroxidase is involved in the hardening of the mosquito egg chorion by catalyzing the formation of ditryrosine through tyrosine residues on structural proteins. The overall hardening of the A. aegypti egg chorion includes both peroxidase-mediated chorion protein crosslinking through dityrosine formation and phenol oxidase-catalyzed chorion melanization.
Aedes↗
[Continuous flow determination of plasma uric acid by an enzyme method using a sequential autoanalyzer. Combination with glucose determination in the presence of glucose oxidase].
The simultaneous assays of glucose and uric acid in blood plasma use first a specific oxidase, then a peroxidase and the same chromogenic system. The coupling of the two methods on Autoanalyser SMA 12/60 use five reagents, three of which are identical in the two methods.
Autoanalysis↗
Biochemical characterization of sap (latex) of a few Indian mango varieties.
Mango sap (latex) from four Indian varieties was studied for its composition. Sap was separated into non-aqueous and aqueous phases. Earlier, we reported that the non-aqueous phase contained mainly mono-terpenes having raw mango aroma (Phytochemistry 52 (1999) 891). In the present study biochemical composition of the aqueous phase was studied. Aqueous phase contained little amount of protein (2.0-3.5 mg/ml) but showed high polyphenol oxidase (147-214 U/mg protein) and peroxidase (401-561 U/mg protein) activities. It contained low amounts of polyphenols and protease activities. On native PAGE, all the major protein bands exhibited both polyphenol oxidase and peroxidase activities. Both polyphenol oxidase and peroxidase activities were found to be stable in the aqueous phase of sap at 4 degrees C. Sap contained large amount of non-dialyzable and non-starchy carbohydrate (260-343 mg/ml sap) which may be responsible for maintaining a considerable pressure of fluid in the ducts. Thus, the mango sap could be a valuable by-product in the mango industry as it contains some of the valuable enzymes and aroma components.
Carbohydrate Metabolism↗
Optical and electrochemical detection of DNA.
There is a growing demand for the production of a DNA biosensor with applications in medicine, the food industry, agriculture, veterinary science and environmental science. In this paper we describe methods for the optical and electrochemical detection of DNA using the enzyme horseradish peroxidase (EC 1.11.1.7) and glucose oxidase (EC 1.1.3.4). We have used bis-methylacridinium nitrate and luminol for the optical detection of DNA using a purpose built, inexpensive luminometer. Using this system detection limits of 10(-11) g of plasmid DNA have been observed. Electrochemical detection of DNA was carried out by the use of a fluoride ion selective electrode and stripping voltammetry. DNA was detected down to 10(-9)-10(-10) g of DNA by the enzymatic release of halogen ions from organohalogen compounds.
Animals↗