Ascorbate Peroxidases: Peroxidases that utilize ASCORBIC ACID as an electron donor to reduce HYDROGEN PEROXIDE to WATER. The reaction results in the production of monodehydroascorbic acid and DEHYDROASCORBIC ACID.PeroxidasesAscorbate Oxidase: An enzyme that converts ascorbic acid to dehydroascorbic acid. EC 1.10.3.3.Ascorbic Acid: A six carbon compound related to glucose. It is found naturally in citrus fruits and many vegetables. Ascorbic acid is an essential nutrient in human diets, and necessary to maintain connective tissue and bone. Its biologically active form, vitamin C, functions as a reducing agent and coenzyme in several metabolic pathways. Vitamin C is considered an antioxidant.Horseradish Peroxidase: An enzyme isolated from horseradish which is able to act as an antigen. It is frequently used as a histochemical tracer for light and electron microscopy. Its antigenicity has permitted its use as a combined antigen and marker in experimental immunology.Glutathione Peroxidase: An enzyme catalyzing the oxidation of 2 moles of glutathione in the presence of hydrogen peroxide to yield oxidized glutathione and water. EC 1.11.1.9.Cytochrome-c Peroxidase: A hemeprotein which catalyzes the oxidation of ferrocytochrome c to ferricytochrome c in the presence of hydrogen peroxide. EC 1.11.1.5.Guaiacol: An agent thought to have disinfectant properties and used as an expectorant. (From Martindale, The Extra Pharmacopoeia, 30th ed, p747)Hydrogen Peroxide: A strong oxidizing agent used in aqueous solution as a ripening agent, bleach, and topical anti-infective. It is relatively unstable and solutions deteriorate over time unless stabilized by the addition of acetanilide or similar organic materials.Peroxidase: A hemeprotein from leukocytes. Deficiency of this enzyme leads to a hereditary disorder coupled with disseminated moniliasis. It catalyzes the conversion of a donor and peroxide to an oxidized donor and water. EC 1.11.1.7.Catalase: An oxidoreductase that catalyzes the conversion of HYDROGEN PEROXIDE to water and oxygen. It is present in many animal cells. A deficiency of this enzyme results in ACATALASIA.Chloroplast Proteins: Proteins encoded by the CHLOROPLAST GENOME or proteins encoded by the nuclear genome that are imported to and resident in the CHOROPLASTS.Chloroplasts: Plant cell inclusion bodies that contain the photosynthetic pigment CHLOROPHYLL, which is associated with the membrane of THYLAKOIDS. Chloroplasts occur in cells of leaves and young stems of plants. They are also found in some forms of PHYTOPLANKTON such as HAPTOPHYTA; DINOFLAGELLATES; DIATOMS; and CRYPTOPHYTA.Antioxidants: Naturally occurring or synthetic substances that inhibit or retard the oxidation of a substance to which it is added. They counteract the harmful and damaging effects of oxidation in animal tissues.Plant Leaves: Expanded structures, usually green, of vascular plants, characteristically consisting of a bladelike expansion attached to a stem, and functioning as the principal organ of photosynthesis and transpiration. (American Heritage Dictionary, 2d ed)Gene Expression Regulation, Plant: Any of the processes by which nuclear, cytoplasmic, or intercellular factors influence the differential control of gene action in plants.Glutathione Reductase: Catalyzes the oxidation of GLUTATHIONE to GLUTATHIONE DISULFIDE in the presence of NADP+. Deficiency in the enzyme is associated with HEMOLYTIC ANEMIA. Formerly listed as EC 1.6.4.2.Spinacia oleracea: A widely cultivated plant, native to Asia, having succulent, edible leaves eaten as a vegetable. (From American Heritage Dictionary, 1982)Oxidative Stress: A disturbance in the prooxidant-antioxidant balance in favor of the former, leading to potential damage. Indicators of oxidative stress include damaged DNA bases, protein oxidation products, and lipid peroxidation products (Sies, Oxidative Stress, 1991, pxv-xvi).Peas: A variable annual leguminous vine (Pisum sativum) that is cultivated for its rounded smooth or wrinkled edible protein-rich seeds, the seed of the pea, and the immature pods with their included seeds. (From Webster's New Collegiate Dictionary, 1973)Plant Proteins: Proteins found in plants (flowers, herbs, shrubs, trees, etc.). The concept does not include proteins found in vegetables for which VEGETABLE PROTEINS is available.Superoxide Dismutase: An oxidoreductase that catalyzes the reaction between superoxide anions and hydrogen to yield molecular oxygen and hydrogen peroxide. The enzyme protects the cell against dangerous levels of superoxide. EC 1.15.1.1.Arabidopsis: A plant genus of the family BRASSICACEAE that contains ARABIDOPSIS PROTEINS and MADS DOMAIN PROTEINS. The species A. thaliana is used for experiments in classical plant genetics as well as molecular genetic studies in plant physiology, biochemistry, and development.Oxidation-Reduction: A chemical reaction in which an electron is transferred from one molecule to another. The electron-donating molecule is the reducing agent or reductant; the electron-accepting molecule is the oxidizing agent or oxidant. Reducing and oxidizing agents function as conjugate reductant-oxidant pairs or redox pairs (Lehninger, Principles of Biochemistry, 1982, p471).Cytosol: Intracellular fluid from the cytoplasm after removal of ORGANELLES and other insoluble cytoplasmic components.Eosinophil Peroxidase: A 66-kDa peroxidase found in EOSINOPHIL granules. Eosinophil peroxidase is a cationic protein with a pI of 10.8 and is comprised of a heavy chain subunit and a light chain subunit. It possesses cytotoxic activity towards BACTERIA and other organisms, which is attributed to its peroxidase activity.Glutathione: A tripeptide with many roles in cells. It conjugates to drugs to make them more soluble for excretion, is a cofactor for some enzymes, is involved in protein disulfide bond rearrangement and reduces peroxides.Dehydroascorbic Acid: The reversibly oxidized form of ascorbic acid. It is the lactone of 2,3-DIKETOGULONIC ACID and has antiscorbutic activity in man on oral ingestion.Droughts: Prolonged dry periods in natural climate cycle. They are slow-onset phenomena caused by rainfall deficit combined with other predisposing factors.Tobacco: A plant genus of the family SOLANACEAE. Members contain NICOTINE and other biologically active chemicals; its dried leaves are used for SMOKING.Iodide Peroxidase: A hemeprotein that catalyzes the oxidation of the iodide radical to iodine with the subsequent iodination of many organic compounds, particularly proteins. EC 1.11.1.8.Molecular Sequence Data: Descriptions of specific amino acid, carbohydrate, or nucleotide sequences which have appeared in the published literature and/or are deposited in and maintained by databanks such as GENBANK, European Molecular Biology Laboratory (EMBL), National Biomedical Research Foundation (NBRF), or other sequence repositories.Arabidopsis Proteins: Proteins that originate from plants species belonging to the genus ARABIDOPSIS. The most intensely studied species of Arabidopsis, Arabidopsis thaliana, is commonly used in laboratory experiments.Salicylic Acid: A compound obtained from the bark of the white willow and wintergreen leaves. It has bacteriostatic, fungicidal, and keratolytic actions.Seedling: Very young plant after GERMINATION of SEEDS.Photosynthesis: The synthesis by organisms of organic chemical compounds, especially carbohydrates, from carbon dioxide using energy obtained from light rather than from the oxidation of chemical compounds. Photosynthesis comprises two separate processes: the light reactions and the dark reactions. In higher plants; GREEN ALGAE; and CYANOBACTERIA; NADPH and ATP formed by the light reactions drive the dark reactions which result in the fixation of carbon dioxide. (from Oxford Dictionary of Biochemistry and Molecular Biology, 2001)Fabaceae: The large family of plants characterized by pods. Some are edible and some cause LATHYRISM or FAVISM and other forms of poisoning. Other species yield useful materials like gums from ACACIA and various LECTINS like PHYTOHEMAGGLUTININS from PHASEOLUS. Many of them harbor NITROGEN FIXATION bacteria on their roots. Many but not all species of "beans" belong to this family.Chlorophyll: Porphyrin derivatives containing magnesium that act to convert light energy in photosynthetic organisms.Peroxisomes: Microbodies which occur in animal and plant cells and in certain fungi and protozoa. They contain peroxidase, catalase, and allied enzymes. (From Singleton and Sainsbury, Dictionary of Microbiology and Molecular Biology, 2nd ed)Plants, Genetically Modified: PLANTS, or their progeny, whose GENOME has been altered by GENETIC ENGINEERING.Plants, Toxic: Plants or plant parts which are harmful to man or other animals.Plant Roots: The usually underground portions of a plant that serve as support, store food, and through which water and mineral nutrients enter the plant. (From American Heritage Dictionary, 1982; Concise Dictionary of Biology, 1990)Abscisic Acid: Abscission-accelerating plant growth substance isolated from young cotton fruit, leaves of sycamore, birch, and other plants, and from potatoes, lemons, avocados, and other fruits.Reactive Oxygen Species: Molecules or ions formed by the incomplete one-electron reduction of oxygen. These reactive oxygen intermediates include SINGLET OXYGEN; SUPEROXIDES; PEROXIDES; HYDROXYL RADICAL; and HYPOCHLOROUS ACID. They contribute to the microbicidal activity of PHAGOCYTES, regulation of signal transduction and gene expression, and the oxidative damage to NUCLEIC ACIDS; PROTEINS; and LIPIDS.Thylakoids: Membranous cisternae of the CHLOROPLAST containing photosynthetic pigments, reaction centers, and the electron-transport chain. Each thylakoid consists of a flattened sac of membrane enclosing a narrow intra-thylakoid space (Lackie and Dow, Dictionary of Cell Biology, 2nd ed). Individual thylakoids are interconnected and tend to stack to form aggregates called grana. They are found in cyanobacteria and all plants.Genes, Plant: The functional hereditary units of PLANTS.Amino Acid Sequence: The order of amino acids as they occur in a polypeptide chain. This is referred to as the primary structure of proteins. It is of fundamental importance in determining PROTEIN CONFORMATION.Isoenzymes: Structurally related forms of an enzyme. Each isoenzyme has the same mechanism and classification, but differs in its chemical, physical, or immunological characteristics.Paraquat: A poisonous dipyridilium compound used as contact herbicide. Contact with concentrated solutions causes irritation of the skin, cracking and shedding of the nails, and delayed healing of cuts and wounds.Plants, Medicinal: Plants whose roots, leaves, seeds, bark, or other constituent parts possess therapeutic, tonic, purgative, curative or other pharmacologic attributes, when administered to man or animals.Lipid Peroxidation: Peroxidase catalyzed oxidation of lipids using hydrogen peroxide as an electron acceptor.Soybeans: An annual legume. The SEEDS of this plant are edible and used to produce a variety of SOY FOODS.Root Nodules, Plant: Knobbed structures formed from and attached to plant roots, especially of LEGUMES, which result from symbiotic infection by nitrogen fixing bacteria such as RHIZOBIUM or FRANKIA. Root nodules are structures related to MYCORRHIZAE formed by symbiotic associations with fungi.Stress, Physiological: The unfavorable effect of environmental factors (stressors) on the physiological functions of an organism. Prolonged unresolved physiological stress can affect HOMEOSTASIS of the organism, and may lead to damaging or pathological conditions.Kinetics: The rate dynamics in chemical or physical systems.Light: That portion of the electromagnetic spectrum in the visible, ultraviolet, and infrared range.Plants: Multicellular, eukaryotic life forms of kingdom Plantae (sensu lato), comprising the VIRIDIPLANTAE; RHODOPHYTA; and GLAUCOPHYTA; all of which acquired chloroplasts by direct endosymbiosis of CYANOBACTERIA. They are characterized by a mainly photosynthetic mode of nutrition; essentially unlimited growth at localized regions of cell divisions (MERISTEMS); cellulose within cells providing rigidity; the absence of organs of locomotion; absence of nervous and sensory systems; and an alternation of haploid and diploid generations.

In vivo role of catalase-peroxidase in synechocystis sp. strain PCC 6803. (1/206)

The katG gene coding for the only catalase-peroxidase in the cyanobacterium Synechocystis sp. strain PCC 6803 was deleted in this organism. Although the rate of H2O2 decomposition was about 30 times lower in the DeltakatG mutant than in the wild type, the strain had a normal phenotype and its doubling time as well as its resistance to H2O2 and methyl viologen were indistinguishable from those of the wild type. The residual H2O2-scavenging capacity was more than sufficient to deal with the rate of H2O2 production by the cell, estimated to be less than 1% of the maximum rate of photosynthetic electron transport in vivo. We propose that catalase-peroxidase has a protective role against environmental H2O2 generated by algae or bacteria in the ecosystem (for example, in mats). This protective role is most apparent at a high cell density of the cyanobacterium. The residual H2O2-scavenging activity in the DeltakatG mutant was a light-dependent peroxidase activity. However, neither glutathione peroxidase nor ascorbate peroxidase accounted for a significant part of this H2O2-scavenging activity. When a small thiol such as dithiothreitol was added to the medium, the rate of H2O2 decomposition in the DeltakatG mutant increased more than 10-fold, indicating that a thiol-specific peroxidase, for which thioredoxin may be the physiological electron donor, is present. Oxidized thioredoxin is likely to be reduced again by photosynthetic electron transport. Therefore, under laboratory conditions, there are only two enzymatic mechanisms for H2O2 decomposition present in Synechocystis sp. strain PCC 6803. One is catalyzed by a catalase-peroxidase, and the other is catalyzed by thiol-specific peroxidase.  (+info)

Systemic signaling and acclimation in response to excess excitation energy in Arabidopsis. (2/206)

Land plants are sessile and have developed sophisticated mechanisms that allow for both immediate and acclimatory responses to changing environments. Partial exposure of low light-adapted Arabidopsis plants to excess light results in a systemic acclimation to excess excitation energy and consequent photooxidative stress in unexposed leaves. Thus, plants possess a mechanism to communicate excess excitation energy systemically, allowing them to mount a defense against further episodes of such stress. Systemic redox changes in the proximity of photosystem II, hydrogen peroxide, and the induction of antioxidant defenses are key determinants of this mechanism of systemic acquired acclimation.  (+info)

Induction of ascorbate peroxidase by ethylene and hydrogen peroxide during growth of cultured soybean cells. (3/206)

In cultured soybean cells, a transient ethylene burst in the pre-stationary phase was followed by an induction of ascorbate peroxidase (AsPOX) in the stationary phase. Treatment of cells with the ethylene antagonist, silver thiosulfate (STS), resulted in the suppression of enzyme activity. Application of the ethylene releasing agent 2-chloroethylphosphonic acid (CEPA) in the medium led to an increased enzyme activity when treated in the pre-stationary phase. On the contrary, a remarkable inhibitory effect on enzyme activity was elicited by 1,3-dimethyl-2-thiourea (DMTU), trapping the hydrogen peroxide generated when treated in the stationary phase. Likewise, a steady level of AsPOX transcript was reduced by STS treatment. Furthermore, its effect appeared to be more rapid and prominent during the pre-stationary phase. It is suggested that the induction of AsPOX in cultured soybean cells during the stationary phase could result, at least in part, by the hydrogen peroxide generated as a result of preceding ethylene production.  (+info)

Stress-induced legume root nodule senescence. Physiological, biochemical, and structural alterations. (4/206)

Nitrate-fed and dark-stressed bean (Phaseolus vulgaris) and pea (Pisum sativum) plants were used to study nodule senescence. In bean, 1 d of nitrate treatment caused a partially reversible decline in nitrogenase activity and an increase in O(2) diffusion resistance, but minimal changes in carbon metabolites, antioxidants, and other biochemical parameters, indicating that the initial decrease in nitrogenase activity was due to O(2) limitation. In pea, 1 d of dark treatment led to a 96% decline in nitrogenase activity and sucrose, indicating sugar deprivation as the primary cause of activity loss. In later stages of senescence (4 d of nitrate or 2-4 d of dark treatment), nodules showed accumulation of oxidized proteins and general ultrastructural deterioration. The major thiol tripeptides of untreated nodules were homoglutathione (72%) in bean and glutathione (89%) in pea. These predominant thiols declined by approximately 93% after 4 d of nitrate or dark treatment, but the loss of thiol content can be only ascribed in part to limited synthesis by gamma-glutamylcysteinyl, homoglutathione, and glutathione synthetases. Ascorbate peroxidase was immunolocalized primarily in the infected and parenchyma (inner cortex) nodule cells, with large decreases in senescent tissue. Ferritin was almost undetectable in untreated bean nodules, but accumulated in the plastids and amyloplasts of uninfected interstitial and parenchyma cells following 2 or 4 d of nitrate treatment, probably as a response to oxidative stress.  (+info)

Peroxisomal membrane ascorbate peroxidase is sorted to a membranous network that resembles a subdomain of the endoplasmic reticulum. (5/206)

The peroxisomal isoform of ascorbate peroxidase (APX) is a novel membrane isoform that functions in the regeneration of NAD(+) and protection against toxic reactive oxygen species. The intracellular localization and sorting of peroxisomal APX were examined both in vivo and in vitro. Epitope-tagged peroxisomal APX, which was expressed transiently in tobacco BY-2 cells, localized to a reticular/circular network that resembled endoplasmic reticulum (ER; 3,3'-dihexyloxacarbocyanine iodide-stained membranes) and to peroxisomes. The reticular network did not colocalize with other organelle marker proteins, including three ER reticuloplasmins. However, in vitro, peroxisomal APX inserted post-translationally into the ER but not into other purified organelle membranes (including peroxisomal membranes). Insertion into the ER depended on the presence of molecular chaperones and ATP. These results suggest that regions of the ER serve as a possible intermediate in the sorting pathway of peroxisomal APX. Insight into this hypothesis was obtained from in vivo experiments with brefeldin A (BFA), a toxin that blocks vesicle-mediated protein export from ER. A transiently expressed chloramphenicol acetyltransferase-peroxisomal APX (CAT-pAPX) fusion protein accumulated only in the reticular/circular network in BFA-treated cells; after subsequent removal of BFA from these cells, the CAT-pAPX was distributed to preexisting peroxisomes. Thus, plant peroxisomal APX, a representative enzymatic peroxisomal membrane protein, is sorted to peroxisomes through an indirect pathway involving a preperoxisomal compartment with characteristics of a distinct subdomain of the ER, possibly a peroxisomal ER subdomain.  (+info)

Transgenic tobacco plants with reduced capability to detoxify reactive oxygen intermediates are hyperresponsive to pathogen infection. (6/206)

Reactive oxygen intermediates (ROI) play a critical role in the defense of plants against invading pathogens. Produced during the "oxidative burst," they are thought to activate programmed cell death (PCD) and induce antimicrobial defenses such as pathogenesis-related proteins. It was shown recently that during the interaction of plants with pathogens, the expression of ROI-detoxifying enzymes such as ascorbate peroxidase (APX) and catalase (CAT) is suppressed. It was suggested that this suppression, occurring upon pathogen recognition and coinciding with an enhanced rate of ROI production, plays a key role in elevating cellular ROI levels, thereby potentiating the induction of PCD and other defenses. To examine the relationship between the suppression of antioxidative mechanisms and the induction of PCD and other defenses during pathogen attack, we studied the interaction between transgenic antisense tobacco plants with reduced APX or CAT and a bacterial pathogen that triggers the hypersensitive response. Transgenic plants with reduced capability to detoxify ROI (i.e., antisense APX or CAT) were found to be hyperresponsive to pathogen attack. They activated PCD in response to low amounts of pathogens that did not trigger the activation of PCD in control plants. Our findings support the hypothesis that suppression of ROI-scavenging enzymes during the hypersensitive response plays an important role in enhancing pathogen-induced PCD.  (+info)

Chlororespiration and poising of cyclic electron transport. Plastoquinone as electron transporter between thylakoid NADH dehydrogenase and peroxidase. (7/206)

Polypeptides encoded by plastid ndh genes form a complex (Ndh) which could reduce plastoquinone with NADH. Through a terminal oxidase, reduced plastoquinone would be oxidized in chlororespiration. However, isolated Ndh complex has low activity with plastoquinone and no terminal oxidase has been found in chloroplasts, thus the function of Ndh complex is unknown. Alternatively, thylakoid hydroquinone peroxidase could oxidize reduced plastoquinone with H(2)O(2). By immunoaffinity chromatography, we have purified the plastid Ndh complex of barley (Hordeum vulgare L.) to investigate the electron donor and acceptor specificity. A detergent-containing system was reconstructed with thylakoid Ndh complex and peroxidase which oxidized NADH with H(2)O(2) in a plastoquinone-dependent process. This system and the increases of thylakoid Ndh complex and peroxidase activities under photooxidative stress suggest that the chlororespiratory process consists of the sequence of reactions catalyzed by Ndh complex, peroxidase (acting on reduced plastoquinone), superoxide dismutase, and the non-enzymic one-electron transfer from reduced iron-sulfur protein (FeSP) to O(2). When FeSP is a component of cytochrome b(6).f complex or of the same Ndh complex, O(2) may be reduced with NADH, without requirement of light. Chlororespiration consumes reactive species of oxygen and, eventually, may decrease their production by lowering O(2) concentration in chloroplasts. The common plastoquinone pool with photosynthetic electron transport suggests that chlororespiratory reactions may poise reduced and oxidized forms of the intermediates of cyclic electron transport under highly fluctuating light intensities.  (+info)

The sorting signals for peroxisomal membrane-bound ascorbate peroxidase are within its C-terminal tail. (8/206)

Peroxisomal ascorbate peroxidase (APX) is a carboxyl tail-anchored, type II (N(cytosol)-C(matrix)) integral membrane protein that functions in the regeneration of NAD(+) in glyoxysomes of germinated oilseeds and protection of peroxisomes in other organisms from toxic H(2)O(2). Recently we showed that cottonseed peroxisomal APX was sorted post-translationally from the cytosol to peroxisomes via a novel reticular/circular membranous network that was interpreted to be a subdomain of the endoplasmic reticulum (ER), named peroxisomal ER (pER). Here we report on the molecular signals responsible for sorting peroxisomal APX. Deletions or site-specific substitutions of certain amino acid residues within the hydrophilic C-terminal-most eight-amino acid residues (includes a positively charged domain found in most peroxisomal integral membrane-destined proteins) abolished sorting of peroxisomal APX to peroxisomes via pER. However, the C-terminal tail was not sufficient for sorting chloramphenicol acetyltransferase to peroxisomes via pER, whereas the peptide plus most of the immediately adjacent 21-amino acid transmembrane domain (TMD) of peroxisomal APX was sufficient for sorting. Replacement of the peroxisomal APX TMD with an artificial TMD (devoid of putative sorting sequences) plus the peroxisomal APX C-terminal tail also sorted chloramphenicol acetyltransferase to peroxisomes via pER, indicating that the peroxisomal APX TMD does not possess essential sorting information. Instead, the TMD appears to confer the proper context required for the conserved positively charged domain to function within peroxisomal APX as an overlapping pER sorting signal and a membrane peroxisome targeting signal type 2.  (+info)

A cDNA for thylakoid-bound ascorbate peroxidase of pumpkin was cloned and characterized. Thylakoid-bound ascorbate peroxidase had a high similarity to cytosolic ascorbate peroxidases, and the precursor contained a transit peptide to chloroplasts at its ammo-terminus and a putative membrane-spanning region at its carboxy-terminus.. ...
Reactive oxygen species (ROS), such as O2 and H2O2, play a key role in plant metabolism, cellular signaling, and defense. In leaf cells, the chloroplast is considered to be a focal point of ROS metabolism. It is a major producer of O2 and H2O2 during photosynthesis, and it contains a large array of ROS-scavenging mechanisms that have been extensively studied. By contrast, the function of the cytosolic ROS-scavenging mechanisms of leaf cells is largely unknown. In this study, we demonstrate that in the absence of the cytosolic H2O2-scavenging enzyme ascorbate peroxidase 1 (APX1), the entire chloroplastic H2O2-scavenging system of Arabidopsis thaliana collapses, H2O2 levels increase, and protein oxidation occurs. We further identify specific proteins oxidized in APX1-deficient plants and characterize the signaling events that ensue in knockout-Apx1 plants in response to a moderate level of light stress. Using a dominant-negative approach, we demonstrate that heat shock transcription factors play a ...
Department of Biological Sciences, Texas Tech University, Lubbock 79409, USA.. An Arabidopsis 14-3-3 protein, AFT1, was used as a bait in the two-hybrid system to identify its interacting proteins. One of the candidate proteins, APX3, was identified as a putative peroxisomal membrane-bound ascorbate peroxidase. Ascorbate peroxidases are important defense enzymes that protect plant cells from oxidative stress damage. DNA blot analysis indicates that APX3 is encoded by a single-copy gene in the Arabidopsis genome. RNA blot analyses show that APX3 transcript levels increase slightly in response to cold, UV light, and treatments with hydrogen peroxide and paraquat. The activity of APX3 in Arabidopsis may be controlled in two ways: its enzymatic activity through protein-protein interactions and its transcription by transcriptional or posttranscriptional regulation.. MeSH Terms ...
We evaluated the H2O2-scavenging activity of the water-water cycle (WWC) in illuminated intact chloroplasts isolated from tobacco leaves. Illumination under conditions that limited photosynthesis [red light (,640 nm), 250 µmol photons m-2 s-1 in the absence of HCO3 -] caused chloroplasts to take up O2 and accumulate H2O2. Concomitant with the O2 uptake, both ascorbate peroxidase (APX) and glyceraldehyde 3-phosphate dehydrogenase (GAPDH) lost their activities. However, superoxide dismutase (SOD), monodehydroascorbate radical reductase (MDAR), dehydroascorbate reductase (DHAR) and glutathione reductase (GR) activities remained unaffected. The extent to which the photosynthetic linear electron flow decreased was small compared with the decline in APX activity. Therefore, the loss of APX activity lowered the electron flux through the WWC, as evidenced by a decrease in relative electron flux through PSII [Φ(PSII)×PFD]. To verify these interpretations, we created a transplastomic tobacco line in ...
Ascorbate peroxidase is a bifunctional peroxidase that catalyzes the H(2)O(2)-dependent oxidation of both ascorbate and various aromatic substrates. The ascorbate binding site was recently identified as being close to the gamma-heme edge [Sharp, K. H., Mewies, M., Moody, P. C. E., and Raven, E. L. (2003)Nat. Struct. Biol. 10, 303-307]. In this work, the X-ray crystal structure of recombinant soybean cytosolic ascorbate peroxidase (rsAPX) in complex with salicylhydroxamic acid (SHA) has been determined to 1.46 A. The SHA molecule is bound close to the delta-heme edge in a cavity that connects the distal side of the heme to the surface of the protein. There are hydrogen bonds between the phenolic hydroxide of the SHA and the main chain carbonyl of Pro132, between the carbonyl oxygen of SHA and the side chain guanadinium group of Arg38, and between the hydroxamic acid group and the indole nitrogen of Trp41. The structure provides the first information about the location of the aromatic binding site ...
Activity of ascorbate peroxidase (APX) (A), glutathione reductase (GR) (B), dehydroascorbate reductase (DR) (C), and monodehydroascorbate reductase (MR) (D) in
H2O2: A Common Denominator That Orchestrates the Molecular Response During Both Biotic and Abiotic Stresses. The signaling role of ROS during temperature stress has been thoroughly studied (34). In our study, the 16 heat shock genes follow the up-regulation of two heat shock transcription factors. This pronounced up-regulation probably reflects the refolding effort of the stressed cells toward oxidatively damaged proteins; however, it cannot be excluded that some specific HSPs play an essential role in the regulation of cell death (35). An oxidative stress-induced heat shock response in plants was evidenced before in Arabidopsis cell suspensions and plants deficient in cytosolic ascorbate peroxidase (10, 12). In addition, several genes previously associated with hypersensitive cell death are also up-regulated (see Table 1). One of these genes, Hsr203J, accelerates the development of hypersensitive cell death when suppressed in transgenic tobacco, suggesting a role in scavenging ROS-derived ...
SWISS-MODEL Template Library (SMTL) entry for 1iyn.1. Crystal structure of chloroplastic ascorbate peroxidase from tobacco plants and structural insights for its instability
John, R., Raja, V., Ahmad, M., Jan, N., Kaul, T. 2017. Trehalose: Metabolism and Role in Stress Signaling in Plants, In: Stress Signaling in Plants: Genomics and Proteomics Perspective, Volume 2, pp.261-275, Sarwat Met al., Springer Publications Doi: 10.1007/978-3-319-42183-4_11. Pandey, S., Fartyal, D., Raina, V., Negi, Y.K., Reddy, M.K., Kaul, T. 2017. Abiotic Stress Tolerance in Plants: Myriad Roles of Ascorbate Peroxidase. Frontiers in Pl Sci 8, 581; Doi: 10.3389/fpls.2017.00581. Yadava, P., Alok, A., Singh, R., Singh, I., Kaul, T., Pattanayak, A., Agrawal, P.K. 2017. Advances in Maize Transformation Technologies and Development of Transgenic Maize. Front Plant Sci 7, 1949. Tripathi K, Pandey S, Sathelly K, Malik M, Kaul T. 2016. Molecular model of thylakoid membrane bound (SlAPX6) Ascorbate Peroxidase from Solanum lycopersicum. Bioinformation (In Press).. Tripathi K, Pandey S, Malik M, Kaul T. 2016. Fruit Ripening of Climacteric and Non Climacteric Fruit. J Environ Appl Bioresearch (In ...
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The level of ascorbate peroxidase is enhanced in benznidazole-resistant populations of Trypanosoma cruzi and its expression is modulated by stress generated by hydrogen peroxide ...
Raven, Emma L. et al "Defining substrate specificity and catalytic mechanism in ascorbate peroxidase." Biochemical Society Symposia 71 (2004): 27-38. Web. 17 Jan. 2018. ...
Amplyx Pharmaceuticals is developing an intravenous and oral formulation of APX 001, for the treatment of multiple fungal infections and acute myeloid
Sweet pepper is susceptible to changes in the environmental conditions, especially temperatures below 15 °C. In this work, two sets of pepper fruits (Capsicum annuum L.) which underwent distinct temperature profiles in planta were investigated. Accordingly, two harvesting times corresponding to each set were established: Harvest 1, whose fruits developed and ripened at 14.9 °C as average temperature; and Harvest 2, with average temperature of 12.4 °C. The oxidative metabolism was analyzed in all fruits. Although total ascorbate content did not vary between Harvests, a shift from the reduced to the oxidized form (dehydroascorbate), accompanied by a higher ascorbate peroxidase activity, was observed in Harvest 2 with respect to Harvest 1. Moreover, a decrease of the ascorbate-generating enzymatic system, the γ-galactono-lactone dehydrogenase, was found at Harvest 2. The activity values of the NADP-dependent dehydrogenases analyzed seem to indicate that a lower NADPH synthesis may occur in fruits which
Sweet pepper is susceptible to changes in the environmental conditions, especially temperatures below 15 °C. In this work, two sets of pepper fruits (Capsicum annuum L.) which underwent distinct temperature profiles in planta were investigated. Accordingly, two harvesting times corresponding to each set were established: Harvest 1, whose fruits developed and ripened at 14.9 °C as average temperature; and Harvest 2, with average temperature of 12.4 °C. The oxidative metabolism was analyzed in all fruits. Although total ascorbate content did not vary between Harvests, a shift from the reduced to the oxidized form (dehydroascorbate), accompanied by a higher ascorbate peroxidase activity, was observed in Harvest 2 with respect to Harvest 1. Moreover, a decrease of the ascorbate-generating enzymatic system, the γ-galactono-lactone dehydrogenase, was found at Harvest 2. The activity values of the NADP-dependent dehydrogenases analyzed seem to indicate that a lower NADPH synthesis may occur in fruits which
Drought stress occurring during the reproductive growth stage leads to considerable reductions in crop production and has become an important limiting factor for food security globally. In order to explore the possible role of drought priming (pre-exposure of the plants to mild drought stress) on the alleviation of a severe drought stress event later in development, wheat plants were subjected to single or double mild drought episodes (soil relative water content around 35-40%) before anthesis and/or to a severe drought stress event (soil relative water content around 20-25%) 15 d after anthesis. Here, single or double drought priming before anthesis resulted in higher grain yield than in non-primed plants under drought stress during grain filling. The photosynthesis rate and ascorbate peroxidase activity were higher while malondialdehyde content was lower in primed plants than in the non-primed plants under drought stress during grain filling. Proteins in flag leaves differently expressed by ...
The binding of substrates to heme enzymes has been widely assumed to occur at the so-called delta-heme edge. Recently, however, a number of examples have appeared in which substrate binding at an alternative site, the gamma-heme edge, is also possible. In previous work [Sharp et al. (2003) Nat. Struct. Biol. 10, 303-307], we showed that binding of ascorbate to ascorbate peroxidase occurred at the gamma-heme edge. Here, we show that the closely related cytochrome c peroxidase enzyme can duplicate the substrate binding properties of ascorbate peroxidase through the introduction of relatively modest structural changes at Tyr36 and Asn184. Hence, crystallographic data for the Y36A/N184R/W191F triple variant of cytochrome c peroxidase shows ascorbate bound to the gamma-heme edge, with hydrogen bonds to the heme propionate and Arg184. In parallel mechanistic studies in variants incorporating the W191F mutation, we show that a transient porphyrin pi-cation radical in Compound I of cytochrome c ...
Changes in the contents of H2O2, malondialdehyde (MDA) and endogenous antioxidants, the activities of enzymes involving cell defense in leaves of strawberry (Fragaria Ananassa Duch.) plantlets under chilling acclimation and de-acclimation were studied. With the increase of chilling acclimation times, the contents of H2O2 and MDA increased to a certain degree and then decreased. The activities of cell defence enzymes, such as Superoxide Dismutase (SOD), catalase (CAT), peroxidase (POD), Dehydroascorbate Reductase (DHAR), Monodehydroascorbate Reductase (MDAR), Ascorbate Peroxidase (APX) and glutathione reductase (GR) were gradually increased to a certain degree and then kept at a high level. And it increased the contents of reduced ascorbate (ASA), dehydroascorbate (DHA) and reduced glutathione (GSH). Our results clearly suggested that cold-hardening triggers an increase of reactive oxygen species (ROS) and the early accumulation of ROS in plants might lead to the production of antioxidant defense ...
Abstract Ionizing radiation directly and indirectly affects gene expression within the plant genome. To access the antioxidant response of rice to different types of ionizing radiation, rice seeds were exposed to gamma-ray, cosmic-ray and ion beam radiation. Exposure to ionizing radiation dramatically decreased the shoot length in all plants but not the root length compared with a non-irradiated plant. Electron spin resonance, confirmed that the number of free radicals in cell was greatly increased by different types of ionizing radiation. The measurement of the MDA, chlorophyll, carotenoids contents and activity of antioxidant enzymes revealed that gamma-ray and cosmic-ray, but not ion beam, ionization deceased chlorophyll and carotenoids contents, while all three ionization treatments increased the activities of peroxidase, ascorbate peroxidase, and superoxide dismutase compared with the non-irradiated plants. Microarray analysis using Affymetrix GeneChip was used to establish the gene transcript
Saldanha, Arun (2013) Bastard and mixed-blood are the true names of race:an introduction. In: Deleuze and race. Deleuze Connections . Edinburgh University Press, Edinburgh, pp. 6-34. ISBN 9780748669585. Saldanha, Arun (2013) Monopolys violence:Georges Bataille explains the early Dutch spice trade. In: Geographies of Race and Food. Ashgate, Aldershot. ISBN 978-1-4094-6927-8. Saldanha, Arun (2013) Power-geometry as philosophy of space. In: Spatial politics. Wiley-Blackwell, Malden, Mass., pp. 44-55. ISBN 9781444338317. Saldanha, Arun and Milevska, Suzana (2013) The eternal return of race:reflections on Eastern European racism. In: Deleuze and race. Edinburgh University Press, Edinburgh, pp. 225-246. ISBN 9780748669585. Sales, Cristina R. G. and Ribeiro, Rafael Vasconcelos and Silveira, Joaquim Albenisio Gomes and Machado, Eduardo Caruso and Martins, Marcio Oliveira and Lagoa, Ana Maria Magalhaes Andrade (2013) Superoxide dismutase and ascorbate peroxidase improve the recovery of photosynthesis in ...
This game uses just 8 events and only 4 for actual game play and you can modify it to go up and down and side to side and add in other obstacles to avoid if you want ...
Lotus Engineering released Friday specs and photos for its APX crossover concept, ahead of its official debut at the Geneva Motor Show next week. In case
Do take a look at my capx, maybe there could be a way to allow enemy chess that are too far from the player chess to select a tile (tileframe =1) that would be in the right direction, towards the player chess (i.e. so as to eventually be "within the moveable area" on a next turn ...
T01816 (acav,adh,amin,apom,arn,arx,asoc,ato,bacs,balt,bara,barw,bcae,bko,camg,cmb,def,fln,frm,gli,gtm,lagl,les,lzy,mbov,mee,ntp,ntt,parb,part,pcx,pht,ppoa,ptu,rhu,sbj,sgv,slau,smal,sphd,sscu,sya,tpaf,trl : calculation not yet completed ...
In this project, the promoter regions of sAPX (At4g08390) and tAPX (At1g77490) were cloned to pHGWFS 7.0 vector and transform to Arabidopsis thaliana. The constructs allow the analysis of the promoter activities by measuring GFP and GUS. Three independent transformation lines were studied for each promoter in order to study the regulation by a spectrum of environmental stimulus. The promoter of tAPX gene was found to be controlled by chloroplastic H2O2. Application of chemicals blocking photosynthestic electron transport upstream of photosystem I suppressed the tAPX promoter activity. However, methyl viologen causing chloroplast reactive oxygen species production increased the tAPX promoter driven reporter expression. mRNA levels of tAPX in 2cpa, 2cpb, and 2cpa2cpb mutants, which have higher chloroplastic H2O2, were higher than in wild type plants. These results suggest a role of chloroplastic H2O2 in regulating tAPX gene. tAPX promoter activity was also shown to be elevated mechanic wounding. Although
Mastocarpus stellatus and Chondrus crispus are red macroalgae that co-dominate the lower rocky intertidal zones of the northern Atlantic coast. M. stellatus is more tolerant than C. crispus of environmental stresses, particularly those experienced during winter. This difference in tolerance has been attributed, in part, to greater contents or activities of certain antioxidants in M. stellatus. We compared the photosynthetic capacities and activities of three antioxidant enzymes--superoxide dismutase (SOD), ascorbate peroxidase (APX), and glutathione reductase (GR)--as well as the contents of ascorbate from fronds of M. stellatus and C. crispus collected over a year. Photosynthetic capacity increased in winter, but did not differ between species in any season. The activities of the three antioxidant enzymes and the contents of ascorbate were significantly greater in tissues collected during months with mean air and water temperatures below 7.5 degrees C (cold months; December, February, March, April)
Abstract:. The mixed salt stress is common in nature. Salt stressalways affects plant growth. Different plant species have different adaptive capacity to salty soil. Leymus chinensis is an herbaceous plant with different leaf colors. However, little research was conducted to explore the different tolerance mechanisms to salt stress among the three different leaf colour genotypes of Leymus chinensis (grey green, transitional color, yellow green). Pot experiments for Leymus chinensis in three leaf colors were conducted under mixed salt treatments in 2010. Malondialdehyde (MDA) and protein concentrations, and the activity of various antioxidant enzymes [i.e., superoxide dismutase (SOD), catalase (CAT), ascorbate peroxidase (APX), glutathione reductase (GR), dehydroascorbate reductase (DHAR) and monodehydroascorbate reductase (MDHAR)] were determined and compared among the three leaf color genotypes of Leymus chinensis. The concentrations of MDA and protein, and the activity of antioxidant enzymes ...
Abstract: Total antioxidative activity, activity of water soluble fraction of antioxidative system, syperoxide dismutase and catalase activities in brain, liver, myocard, skeletal muscle, kidney and serum at hypothermia 300С, 200С and self-warming from 200С to 370С were studied. Activity of antioxidative system is sustained at high level, except superoxide dismutase. The latter is activated significantly at 300С hypothermia prolonged up to 3 h. Dalargin injection 30 min before onset of cooling stabilizes the erythrocyte membrane without enhancement of antioxidative activity in majority of investigated ...
One of the biggest problems today is pollution. Contamination with heavy metals which includes the lead (Pb), is a distinct problem because metals are not biodegradable and have negative impact on the living world. Ecologically and enivronmentally acceptable solution provides a new biotehnological process called phytoremediation, which is based on the ability of plants to clean and restore contaminated area. This study was used to assay the effect of lead on the growth of poplar (Populus nigra var. italica), phytoextraction potential of poplar for lead, his redistribution in certain parts of the plant, (H2O2), and the effects of lead in the soil on the activity of antioxidant enzymes like superoxide dismutase (SOD), peroxidase (POD), catalase (CAT), ascorbate peroxidase (APOX), glutathione-S-transferase (GST) and glutathione reductase (GR). All of the results together inicate that the studied poplar (Populus nigra var. italica) can be considered as a species with the potential use in ...
Amalaki contains cytokine-like substances identified as zeatin, zeatin riboside, and zeatin nucleotide. It has antibacterial, cardiotonic, antioxidative, antiviral, and resistance-building properties that help prevent infection. This fruit is one of the richest natural sources of vitamin C, containing up to 720 mg of vitamin C per 100 g of fresh pulp and 921 mg per 100 cc of pressed juice. This is approximately 20 times the vitamin C content of an orange. Vitamin C is an antioxidant and acts as a substrate for ascorbate peroxidase which is an enzyme that detoxifies peroxides to reduce oxidative damage to biomolecules and cells. Vitamin C is essential for life and for maintaining optimal health against colds and many other diseases. It is required to synthesize carnitine, which is important in the transfer of energy to the mitochondria which serve as cellular power-plants ...
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MONTEIRO, Carolina C. et al. Biochemical and histological characterization of tomato mutants. An. Acad. Bras. Ciênc. [online]. 2012, vol.84, n.2, pp.573-585. Epub Apr 19, 2012. ISSN 0001-3765. http://dx.doi.org/10.1590/S0001-37652012005000022.. Neste trabalho, analisamos as respostas bioquímicas inerentes ao sistema antioxidante, assim como propriedades morfológicas e anatômicas de mutantes fotomorfogenéticos e hormonais de tomateiro. Comparados ao não mutante Micro-Tom (MT), observamos que o conteúdo de malondialdeído (MDA) aumentou nos mutantes diageotropica (dgt) e lutescent (l), enquanto os maiores níveis de H2O2 foram encontrados nos mutantes high pigment 1 (hp1) e aurea (au). Análises de enzimas antioxidantes mostraram que todos os mutantes reduziram a atividade de catalase (CAT) quando comparado a MT. A guaiacol peroxidase (GPOX) aumentou em ambos os mutantes sitiens (sit) e notabilis (not), enquanto no mutante not houve aumento da atividade de ascorbato peroxidase (APX). ...
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To assess nickel-induced toxicity in plants, Zea mays seeds were germinated and cultured on nutrient solution with nickel concentrations of 50-200 μM for a period of two weeks. Observed biological makers included biomass, soluble and total protein contents, and the activities of guaiacol peroxidase (GPX), ascorbate peroxidase (APX), catalase (CAT), and phenylalanine ammonia-lyase (PAL) in the leaves and roots of maize. The fresh and dry weight of leaves and roots increased in 50 μM nickel but decreased in 100 and 200 μM. Soluble and total protein contents were significantly increased by increasing nickel concentrations up to 200 μM nickel in both roots and leaves of maize. Significant increases of ascorbate peroxidase (the highest activity at 200 μM nickel), catalase (the highest activity at 50 μM nickel), and phenylalanine ammonia-lyase (the highest activity at 100 μM nickel) were observed in the leaves and roots of Zea mays seedlings at all tested nickel concentrations. Guiacol peroxidase
Physiological processes are influenced by environmental factors and plant characteristics. The distribution of photosynthetic capacity of phyllodes of Acacia mangium Willd. seedlings was studied in relation to the in vivo photosystem II (PSII) function, photosynthetic gas exchange, chlorophyll fluorescence and activities of antioxidant enzymes (superoxide dismutase (SOD) and ascorbate peroxidase (APX)) of phyllodes at different positions on seedlings. There was a vertical gradient in photosynthetic capacity of phyllodes along the shoot. Phyllode 1 (at the apex) showed negative carbon uptake at PPFD lower than 400 μmol m-2 s-1. High photosynthetic capacities, chlorophyll concentrations, ΔF/F(m), and q(P), were observed in phyllodes 4, 6 and 8. The high photosynthetic capacities of mature phyllodes could be attributed to the enhanced availability of CO2 and the high efficiency of PSII in energy absorption and utilization. Total SOD and APX activities (on a dry weight basis) were highest at ...
This book provides an overview of antioxidants and antioxidant enzymes and their role in the mechanisms of signaling and cellular tolerance under stress in plant systems. Major reactive oxygen species (ROS)-scavenging/modulating enzymes include the superoxide dismutase (SOD) that dismutates O2 into H2O2, which is followed by the coordinated action of a set of enzymes including catalase (CAT), ascorbate peroxidase (APX), glutathione peroxidase (GPX) and peroxiredoxins (Prx) that remove H2O2. In addition to the ROS scavenging enzymes, a number of other enzymes are found in various subcellular compartments, which are involved in maintaining such redox homeostasis either by directly scavenging particular ROS and ROS-byproducts or by replenishing antioxidants. In that respect, these enzymes can be also considered antioxidants. Such enzymes include monodehydroascorbate reductase (MDAR), dehydroascorbate reductase (DHAR), glutathione reductase (GR), alternative oxidases (AOXs), peroxidases (PODs) and ...
A split-plot design was used to study the physiological responses of anti-oxidative enzymes and carbohydrate contents of bermudagrass to different durations (0, 3, 7, 15, 30, 60, 90, 120 and 150 days) and depths of submergence (0, 1, 5 and 15 m). The results suggest that submergence caused a higher production of malondialdehyde and more significant changes in the different submerged treatments. The activities of catalase (CAT), superoxide dismutase (SOD), peroxidase (POD), ascorbate peroxidase (APX) and glutathione reductase (GR) in roots increased with the increase of the durations and depths of submergence, implying an integrated pathway involving CAT, SOD, POD, GR and APX for protection against the detrimental effects of activated oxygen species under submergence. Total soluble carbohydrate and starch contents of shoots and roots decreased with the increase of the depth and duration of submergence, but remained at relatively high level at the end of the study, showing quiescence is one of the ...
Powered by The levels written into the ascorbate glutathione pathway and point. The future is from the pretty surveys of the Other class structure. This proves applied the exegetical ascorbate glutathione business( method Molecular agregar to Thank one CANVAS, which tends with the research at so 16 variants. It is three applications and three images. make dealing ascorbate glutathione pathway sources! appoint degrees into semantics with a Historical stage. You can contain your essential remarks! is the happy rainwater ebook production; learning! Design by ascorbate glutathione pathway and stress tolerance in plants of Slotted Deadline Sensitive Leases in Infrastructure CloudLecture Notes in Computer Science, specialized BhiseDownload with GoogleDownload with Facebookor assimilation with teacher of Slotted Deadline Sensitive Leases in Infrastructure CloudDownloadAllocation of Slotted Deadline Sensitive Leases in Infrastructure CloudMinal BhiseLoading PreviewSorry, table, has accordingly ...
BMB Rep. 2010 Oct;43(10):688-92. Preventable effect of L-threonate, an ascorbate metabolite, on androgen-driven balding via repression of dihydrotestosterone-in
The present study illustrates the effect of 24-epibrassinolide (24-EBL) on morphological and biochemical parameters in radish (Raphanus sativus L.) seedlings grown under nickel (Ni) ion stress. The radish seeds pre-soaked in different concentrations of 24-EBL were sown in petridishes containing various concentrations of heavy metal (Ni).Observations were made on root/shoot length, fresh biomass, activities of antioxidant enzymes (ascorbate peroxidase, superoxide dismutase, catalase, monodehydroascorbate reductase, dehydroascorbate reductase, guaiacol peroxidase and glutathione reductase), lipid peroxidation, proline and protein content in 7-day-old Ni-stressed radish seedlings. Results indicate that seeds presoaked with 24-EBL reduced the impact of Ni-stress which was evident by assessing the morphological parameters, protein content and antioxidant enzyme activities. It was also observed that 24-EBL reduced the toxicity of heavy metal by influencing proline and malondialdehyde (MDA) content. The
Its name immediately makes you want to know more - exploding cucumber plant or squirting cucumber plant. So what are squirting cucumber plants? Where on earth does the volatile squirting cucumber grow? Click this article to learn more.
The 2-Cys peroxiredoxin-A (2CPA) promoter is a model promoter to study redox and ABA-dependent stress signaling. Here, an Arabidopsis reporter gene line expressing luciferase under control of the 2CPA promoter was used to study the impact of ascorbate on reporter gene transcription in a series of protoplast and leaf slice incubation experiments. It was shown that ascorbate has a dual function on gene expression regulation. First, a comparison of responses to ascorbate, dehydroascorbate and reduced and oxidized glutathione demonstrated that ascorbate feeding supports gene expression regulation by increasing the catalytic capacity in redox signaling, as defined by the concentration of low molecular weight antioxidants and their oxidized counterparts. Second, ascorbate had a specific and light-dependent effect on 2CPA transcription, which cannot be substituted by reduced glutathione. Based on the differences between ascorbate and glutathione in the subcellular redox-cycling capacities, it is ...
The class is the Cell Structure and Function Laboratory. Hell yeah, doesnt that sound fascinating? Its the fall sophomore lab everyone is required to take. I didnt want to teach the little freshmen who knew absolutely nothing, and this class was actually pretty good when I took it. Its also not too mentally strenuous. Basically you set up your gel, sit around while your gel is running, and then interpret your gel. Oh, and a lot of stuff with hemoglobin and peroxidase isoenzymes. Exciting stuff.. I just hope Im a good TA. I dont want to be the jerk or the confused one who comes off as being really stupid. I want to be the cool TA, the one that actually remembers your name and jokes with you and is useful. Oi. And then the fear settles in that Im being trusted with a new generation of scientists… As long as I dont spill ethidium bromide all over them, Im probably okay.. ...
Ascorbate recycling in human neutrophils: Induction by bacteria: Ascorbate (vitamin C) recycling occurs when extracellular ascorbate is oxidized, transported as
my %callbacks = ( test =, sub { my $test = shift; if ( $test-,is_ok && not $test-,directive ) { # normal passing test print color green; } elsif ( !$test-,is_ok ) { # even if its TODO print color white on_red; } elsif ( $test-,has_skip ) { print color white on_blue; } elsif ( $test-,has_todo ) { print color white; } }, ELSE =, sub { # plan, comment, and so on (anything which isnt a test line) print color black on_white; }, ALL =, sub { # now print them print shift-,as_string; print color reset; print \n ...
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The arsenic (As) influence on the relative growth rate (TCR) and on the antioxidant system of four leguminous species: Leucocephala leucocephala, Sesbania grandiflora (woody), Cajanus cajan and Crotalaria spectabilis (shrub), it was evaluated, as well as, the accumulation of this element for these species. After the exhibition of these species to the As, in nutritious solution, they were appraised TCR and the enzymatic activity of the enzymes: superoxide dismutase (SOD), catalase (CAT), peroxidase (POX), ascorbate peroxidase (APX) and glutathione reductase (GR) and the accumulation of As for the same ones. Of the woody species, S. grandiflora showed minor influences of the As on TCR, besides presenting larger accumulation of this element than L. leucocephala. The largest tolerance presented by S. grandiflora can be related to efficient of the antioxidant system of the same. S. grandiflora, when cultivated in nutritious solution without addition of As, it presented the largest activities of the ...
Two days ago, Curiosity stopped to analyze a football-size piece of Martian basalt called Jake Matijevic. Not only did Curiosity analyze the rocks structure and chemical makeup using itsChemCam spectroscopic laser, but it also used its Alpha Particle X-Ray Spectrometer (APXS) for the first time, and also took the first ultra-close-up photos using the MAHLI camera. The rock was primarily chosen to see if the results from APXS match up with ChemCam.. ...
Cucumbers require warm days, plenty of sunshine and cool nights for best growth. They are a fast-growing crop ready for harvest in 50 to 70 days. If bugs are eating your cucumber plants, identify ...
phpinfo() PHP Version =, 5.4.0 System =, Linux Myrmidon 2.6.32-5-amd64 #1 SMP Mon Jan 16 16:22:28 UTC 2012 x86_64 Build Date =, Mar 10 2012 16:50:13 Configure Command =, ./configure --prefix=/usr/local/PHP--with-mysql=/usr/local/bin/mysql--with-apxs2=/usr/local/apache2/bin/apxs Server API =, Command Line Interface Virtual Directory Support =, disabled Configuration File (php.ini) Path =, /usr/local/PHP--with-mysql=/usr/local/bin/mysql--with-apxs2=/usr/local/apache2/bin/apxs/lib Loaded Configuration File =, (none) Scan this dir for additional .ini files =, (none) Additional .ini files parsed =, (none) PHP API =, 20100412 PHP Extension =, 20100525 Zend Extension =, 220100525 Zend Extension Build =, API220100525,NTS PHP Extension Build =, API20100525,NTS Debug Build =, no Thread Safety =, disabled Zend Signal Handling =, disabled Zend Memory Manager =, enabled Zend Multibyte Support =, disabled IPv6 Support =, enabled DTrace Support =, disabled Registered PHP Streams =, php, file, glob, data, ...
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The Determination of Peroxidase in Amniotic Fluid.: Analyzing total peroxidase activity in amniotic fluid is extremely simple, requiring only 1 1/2 minutes of i
Previous observations have indicated that the red peel areas of grapefruit with high lycopene concentrations were more tolerant to CI than yellow peel areas (Lado et al., 2015a). Because lycopene is a carotene with powerful antioxidant capacity, this study investigated whether the CI tolerance of the lycopene-accumulating rind of grapefruit may be due to an enhancement of the enzymatic and/or nonenzymatic antioxidant systems. Total antioxidant capacity, antioxidant metabolite (GSH and AsA) contents, and antioxidant enzyme (GR [glutathione reductase], ascorbate peroxidase [APX], catalase [CAT] and superoxide dismutase [SOD]) activity and gene expression were measured in the peel of Star Ruby grapefruit with contrasting CI tolerance during storage at 2 C for up to 58 d. The peel of CI-tolerant fruit exhibited a lower lipid peroxidation level (MDA content). The hydrogen peroxide concentration was similar after 3 weeks of storage, when the differences in chilling damage between sensitive and ...
Pretreatment of the first true leaves of oilseed rape plants (Brassica napus cv. Bristol) with menadione sodium bisulphite (MSB) locally and systemically induced resistance, as shown by reduced lesion size and number, to infection by the fungal pathogen Leptosphaeria maculans, the causal agent of stem canker. Using a known systemic activator of salicylic acid-dependent PR-1 induction, acibenzolar-S-methyl (BTH; S-methylbenzo[1,2,3]thiadiazole-7-carbothiate) as a comparison, real-time PCR expression analysis of genes encoding a pathogenesis-related protein 1 (PR-1) and an ascorbate peroxidase (APX) demonstrated a systemic enhancement of APX expression in MSB-pretreated plants, with no effect on PR-1 expression, suggesting augmented reactive oxygen species production in MSB-pretreated plants. The results demonstrate MSB to be an effective resistance activator in oilseed rape, and potentially useful for the control of stem canker ...
The anti-senescence biogenic polyamines (PAs) putrescine (Put), spermidine (Spd) and spermine (Spm) are involved in plant growth processes and responses to stress. The physiological mechanism of exogenous Put to affect the senescence of cut lisianthus flowers during vase life was investigated. Fresh cut lisianthus flowers were treated with distilled water (control), 0.5, 1 and 2 mM Put and then held at 25 ◦C up to 12 days. Exogenous Put supply at 2 mM extended vase life, which was associated with reduced electrolyte leakage and MDA content. Put treatment also reduced activity of lipoxygenase (LOX), is responsible for membrane lipid peroxidation. Put treatment also enhanced activities of catalase (CAT) and ascorbate peroxidase (APX) and decreased H2O2 accumulation during vase life. Thus, exogenous Put supplycould maintain membrane integrity by increasing antioxidant system activity, thereby retarding the senescence of cut lisianthus flower during vase life.
Why do we need Sodium Ascorbate?. The GLO Gene is absent in many people. Scientists believe that this happened around 60 million years ago. The absence of this gene makes us unable to biosynthesize the specific enzyme L- gulonolactone oxidase. This is an end-stage liver enzyme that bio-converts blood glucose to Ascorbate; without it, our bodies cannot produce any Ascorbate. In the long term, the lack of Ascorbate causes our bones to dissolve and teeth to fall out; in other words, sub-clinical scurvy and a tendency to develop cancer.. Ascorbic Acid is produced in large quantities in almost all animals, e.g. 6 grams a day in goat, or up to 100grams daily if the goat is stressed. But it is not the Ascorbic Acid our body requires, rather a SALT of Ascorbic Acid. A daily supplementation of Ascorbate several times a day is a simple way to make up for this genetic defect.. Robert F. Cathcart, MD another medical pioneer who has had great success with Ascorbate, successfully treating over 25,000 patients ...
In my home garden, my cucumber plant leaves are turning brown/ yellow. It seems to be spreading. What should I do? I worked so hard on...
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InterPro provides functional analysis of proteins by classifying them into families and predicting domains and important sites. We combine protein signatures from a number of member databases into a single searchable resource, capitalising on their individual strengths to produce a powerful integrated database and diagnostic tool.
peroxidase: Any of a group of enzymes that occur especially in plant cells and catalyze the oxidation of a substance by a peroxide.
Histofine Simple Stain MAX Peroxidase (Human Tissue, Mouse primary): 414131F by As One International, Inc. at Labscoop.com - Read reviews, citations, datasheets, protocols & more.
Duconge, J. (2008). Pharmacokinetics of vitamin C: insights into the oral and intravenous administration of ascorbate. P R Health Sci J., [online] 27(1), pp.7-19 ...
Duconge, J. (2008). Pharmacokinetics of vitamin C: insights into the oral and intravenous administration of ascorbate. P R Health Sci J., [online] 27(1), pp.7-19 ...
Your basket is currently empty. i ,p>When browsing through different UniProt proteins, you can use the basket to save them, so that you can back to find or analyse them later.,p>,a href=/help/basket target=_top>More...,/a>,/p> ...
Arbuscular mycorrhizas (AMs), formed between AM fungi and vascular plants, are a widespread mutualistic symbiosis where fungi colonize root cells, transfer mineral nutrients (mainly phosphate) and, in turn, obtain carbon of a photosynthetic origin. To explore the possible roles played by antioxidant enzymes in the roots and shoots of AM-inoculated potato cultivars, a field experiment was conducted using three potato cultivars (Agria, Santé and Arinda) and two Glomus intraradices levels (0 and 30 g). The leaf and root activities of catalase (CAT), peroxidase (POX) and ascorbate peroxidase (APX) affecting mycorrhizal colonization and potato yield were measured. Under AM inoculation, the three CAT, POX and APX enzymes were induced in both the roots and leaves of all the cultivars. However, the highest increases in POX, APX and CAT activities under AM inoculation were noted in the leaves of Santé and the roots of Arinda. Mycorrhizal colonization was more pronounced under arbuscular mycorrhiza ...
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Catalyzes the conversion of monodehydroascorbate (MDA) to ascorbate, oxidizing NADH in the process. Can also use 2,4,6-trinitrotoluene (TNT) and 1-chloro-2,4-dinitrobenzene (CDNB) as substrates, but not 1-chloro-4-nitrobenzene (CNB).
Title: Recents Patents in the Use of Peroxidases. VOLUME: 3 ISSUE: 2. Author(s):Berenize Alvarado and Eduardo Torres. Affiliation:Benemerita Universidad Autonoma de Puebla, Centro de Quimica-ICUAP. Ciudad Universitaria, Puebla, 72570. Mexico.. Keywords:Biosensor, enzymatic oxidation, peroxidases, review. Abstract: Peroxidases are hemoenzymes with a wide range of applications, from fine chemical synthesis to environmental biocatalysis. These outstanding biocatalysts are able to catalyze reactions such as heteroatom oxidation (Nand S-oxidation), epoxidation, hydroxylation, and the oxidation of alcohols and indole, often giving high yields and enantiomeric excess values. This makes these biocatalysts very useful for application to several biotechnological processes. In this paper, recent advances and patents surrounding the use of peroxidases are reviewed, covering different aspects related to the applications of peroxidases and the modifications carried out to improve their functionality as ...
Magnesium Ascorbate Buffered Form Vitamin C (Hypoallergenic) 100 capsules Magnesium Ascorbate is a buffered, non-acidic form of vitamin C (pH of 7.0), which is generally gentler to the stomach than ascorbic acid, and is well tolerated by the bowel.Suggested Use: As a dietary supplement, 1 or 2 capsules one to three times daily between meals, or as directed by a healthcare practitioner. Serving Size 1 capsule Servings per container 100 Amount per serving: Vitamin C (as Magnesium Ascorbate) 500 mg Magnesium (as Magnesium Ascorbate) 35 mg Other ingredients: Gelatin, cellulose, magnesium stearate. These nutrients are of the highest quality and purity obtainable, and do not contain preservatives, diluents, or artificial additives. Keep in a cool, dry place, tightly capped.
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Now Vitamins - Sodium Ascorbate 3 Lb 100% Pure Vitamin C Powder Sodium Ascorbate is not acidic and will ...
More than 40 different diseases infect cucumbers, and theyre susceptible to weeds and insect pests when growing conditions arent right. Recognise some of the common diseases help you prevent loss of fruit. Your local county extension office has information about treating plant diseases in your area.
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Viridian HIGH FIVE B-Complex and Magnesium Ascorbate is packed with nutrients to support a busy and demanding lifestyle, including all the B Complex vitamins and vitamin C to help maintain adrenal function.
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Thank you for sharing this Cancer Discovery article.. NOTE: We request your email address only to inform the recipient that it was you who recommended this article, and that it is not junk mail. We do not retain these email addresses.. ...
Ascorbate and glutathione (GSH) are the primary water-soluble antioxidants in the CNS. Oxidative stress, sometimes indicated by loss of these antioxidants, has been linked to several clinical and experimental conditions, including cerebral ischemia. These conditions are also gender-linked, with greater incidence or severity in males than females. To test whether there are gender differences in oxidant/antioxidant regulation, we determined basal levels of ascorbate and GSH in rat brain and their loss after 1 h decapitation ischemia. We found that ascorbate levels in male rat brain were 7-10% higher than in females, depending on region, whereas GSH levels were gender-independent. Significant ascorbate loss (up to 12%) occurred in males during ischemia, with a regional pattern of cerebellum | hippocampus | prefrontal cortex. Loss of ascorbate in females was not significant in any region. By contrast, loss of GSH was significant in both males and females. Greater loss of GSH than ascorbate was in agreement
Magnesium Ascorbate 8 oz powder- Magnesium Ascorbate is a buffered (non-acidic) form of Vitamin C that will not contribute to gastric irritation in acid-sensitive persons. Magnesium Ascorbate is synthesized from a combination of Ascorbic Acid and Magnesium to form Magnesium Ascorbate. NOW® also distributes a variety of powdered vitamins and minerals including Pure Ascorbic Acid, Calcium Ascorbate, Sodium Ascorbate and Vitamin C Complex Powder.Suggested Serving Size: 1/4 Teaspoon (1.0 g)Number of Servings: N/ASuggested Use: As a dietary supplement, take 1/4 level teaspoon daily, preferably with meals.Free of: sugar, salt, starch, yeast, wheat, gluten, milk, soy, preservatives, chemical additives or artificial colors.Ingredients: N/AWarnings: NoneDisclaimer: *This statement has not been evaluated by the FDA. This product is not intended to diagnose, treat, cure or prevent any disease.
The first analysis on a rock started on Sol 3 with Barnacle Bill. The Alpha Particle X-ray Spectrometer (APXS) was used to determine its composition, the spectrometer taking ten hours to make a full scan of the sample. It found all the elements except hydrogen, which constitutes just 0.1 percent of the rocks or soils mass.. The APXS works by irradiating rocks and soil samples with alpha particles (helium nuclei, which consist of two protons and two neutrons). The results indicated that "Barnacle Bill" is much like Earths andesites, confirming past volcanic activity. The discovery of andesites shows that some Martian rocks have been remelted and reprocessed. On Earth, Andesite forms when magma sits in pockets of rock while some of the iron and magnesium settle out. Consequently, the final rock contains less iron and magnesiums and more silica. Volcanic rocks are usually classified by comparing the relative amount of alkalis (Na2O and K2O) with the amount of silica (SiO2). Andesite is different ...
TY - JOUR. T1 - Analysis of heat-labile sites generated by reactions of depleted uranium and ascorbate in plasmid DNA. AU - Wilson, Janice. AU - Young, Ashley. AU - Civitello, Edgar R. AU - Stearns, Diane M. PY - 2014. Y1 - 2014. N2 - The goal of this study was to characterize how depleted uranium (DU) causes DNA damage. Procedures were developed to assess the ability of organic and inorganic DNA adducts to convert to single-strand breaks (SSB) in pBR322 plasmid DNA in the presence of heat or piperidine. DNA adducts formed by methyl methanesulfonate, cisplatin, and chromic chloride were compared with those formed by reaction of uranyl acetate and ascorbate. Uranyl ion in the presence of ascorbate produced U-DNA adducts that converted to SSB on heating. Piperidine, which acted on DNA methylated by methyl methanesulfonate to convert methyl-DNA adducts to SSB, served in the opposite fashion as U-DNA adducts by decreasing the level of SSB. The observation that piperidine also decreased the gel shift ...
Pretreatment of a serum or plasma sample with ascorbate oxidase removed interfering ascorbate and allowed the determination of cholesterol to be carried out by a current enzymatic cholesterol method available in kit form. The Cobas-Fara was programmed to carry out pretreatment of the sample with ascorbate oxidase before addition of the cholesterol colour reagent.. ...
Oelrichs B.A., Kelly J.D., Kratzing C.C. and Winzor D.J. (1988) Accumulation of ascorbate in rat cerebellum. International Journal for Vitamin and Nutrition Research, 58 2: 213-217. ...
GenDR A curated database of genes associated with dietary restriction in model organisms either from genetic manipulation experiments or gene expression profiling.. ...
Patients with advanced cancers of the stomach, bronchus, colon, ovary or breast were treated with ascorbate. The purpose of the study was to determine if the survival times differ with respect to the organ affected by the cancer. Variables. ...
Heme peroxidases are widely distributed in biological systems and are involved in a wide range of processes essential for life. This book provides a comprehensive single source of information on the various aspects of heme peroxidase structure, function and mechanism of action. Chapters written and edited by worldwide experts span a range of heme peroxidases from plants, yeast, bacteria and mammals. Discussed functions of peroxidases range from cell wall synthesis, synthesis of prostaglandins, role in drug suppression of tuberculosis, and antibacterial activity. Included is a discussion of peroxidases that also act as catalases and oxygenases. Heme Peroxidases serves as an essential text for those working in industry and academia in biochemistry and metallobiology.
Disclosed is a diagnostic test device which comprises a fluid permeable structural support member having on one side thereof a layer of a macroporous membrane comprising polyethyleneimine impregnated with iodate ion and on the other side of the support member having a layer of a microporous membrane having dispersed therein a chromogenic indicator capable of providing a colored response upon being oxidized. The intensity of the colored response is less subject to ascorbate interference due to the activity of the iodate ion.
Juglone (5-hydroxy-1,4-naphthoquinone), occurs naturally in the leaves, roots, husks, and bark of plants in the Juglandaceae family, particularly the black wa...
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... such as ascorbate in the glutathione-ascorbate cycle, glutathione peroxidases and glutaredoxins, as well as reacting directly ... There are at least four different glutathione peroxidase isozymes in animals.[154] Glutathione peroxidase 1 is the most ... Peroxidases. catalase. H. 2. O. Water. {\displaystyle {\ce {{\underset {Oxygen}{O2}}-,{\underset {Superoxide}{*O2^{-}}}-,[{\ce ... "Regulation and function of ascorbate peroxidase isoenzymes". Journal of Experimental Botany. 53 (372): 1305-19. doi:10.1093/ ...
Regulation and function of ascorbate peroxidase isoenzymes». Journal of Experimental Botany. 53 (372): 1305-19. PMID 11997377. ... Existem pelo menos quatro isozimas glutationa peroxidases diferentes nos animais.[131] A glutationa peroxidase 1 é a mais ... Por sua vez, a glutationa peroxidase 3 é mais activa contra os hiperóxidos lípidos. Surpreendentemente, a glutationa peroxidase ... O sistema da glutationa contém glutationa, glutationa redutase, glutationa peroxidases e glutationa S-transferase.[74] Este ...
La peroxidation des lipides augmente; Les enzymes antioxidants tels que superoxide dismutase, ascorbate peroxidase, glutathione ...
"Inactivation of Ascorbate Peroxidase in Spinach Chloroplasts on Dark Addition of Hydrogen Peroxide: Its Protection by Ascorbate ... "Monodehydroascorbate Reductase in Spinach Chloroplasts and Its Participation in Regeneration of Ascorbate for Scavenging ...
This photochemical H 2O 2 is then reduced by the action of ascorbate peroxidase (APX) to form water and oxidized ascorbate. ...
... ascorbate, carotenoids, superoxide dismutase, catalase, and glutathione peroxidase. These antioxidants provide protection from ...
"Regulation and function of ascorbate peroxidase isoenzymes". J Exp Bot 53 (372): 1305 - 19. doi:10.1093/jexbot/53.372.1305. ... Brigelius-Flohé R (1999). "Tissue-specific functions of individual glutathione peroxidases". Free Radic Biol Med 27 (9-10): 951 ... "Mechanisms of compound I formation in heme peroxidases". J Inorg Biochem 91 (1): 27-34. doi:10.1016/S0162-0134(02)00390-2. ... "Glutathione peroxidase 4 senses and translates oxidative stress into 12/15-lipoxygenase dependent- and AIF-mediated cell death ...
... ascorbate peroxidase, and glutathione peroxidase). The antioxidant superoxide dismutase catalyses the formation of hydrogen ... "Temporal mismatch between induction of superoxide dismutase and ascorbate peroxidase correlates with high H2O2 concentration in ...
Shigeoka S, Ishikawa T, Tamoi M, Miyagawa Y, Takeda T, Yabuta Y, Yoshimura K «Regulation and function of ascorbate peroxidase ... Hiner A, Raven E, Thorneley R, García-Cánovas F, Rodríguez-López J «Mechanisms of compound I formation in heme peroxidases». J ... Les peroxiredoxiness són peroxidases que catalitzen la reducció de peròxid d'hidrogen, hidroperòxid orgànic i peroxinitrit.[73] ... Brigelius-Flohé R «Tissue-specific functions of individual glutathione peroxidases». Free Radic Biol Med, 27, 9-10, 1999, pàg. ...
Ting has also developed the APEX (engineered ascorbate peroxidase) reporter for proteomic mapping of living cells, and electron ...
In plants, vitamin C is a substrate for ascorbate peroxidase. This enzyme utilizes ascorbate to neutralize toxic hydrogen ... Ascorbate salts such as sodium ascorbate and calcium ascorbate are used in some dietary supplements. These release ascorbate ... However, taking vitamin C in the form of sodium ascorbate and calcium ascorbate may minimize this effect. Other symptoms ... The most commonly used supplement compounds are ascorbic acid, sodium ascorbate and calcium ascorbate. Vitamin C molecules can ...
... iodide peroxidase EC 1.11.1.9: glutathione peroxidase EC 1.11.1.10: chloride peroxidase EC 1.11.1.11: L-ascorbate peroxidase EC ... NADH peroxidase EC 1.11.1.2: NADPH peroxidase EC 1.11.1.3: fatty-acid peroxidase EC 1.11.1.4: now *EC 1.13.11.11 EC 1.11.1.5: ... versatile peroxidase EC 1.11.1.17: glutathione amide-dependent peroxidase EC 1.11.1.18: bromide peroxidase EC 1.11.1.19: dye ... cytochrome-c peroxidase EC 1.11.1.6: catalase EC 1.11.1.7: peroxidase EC 1.11.1.8: ...
在人體內,維生素C是高效抗氧化劑,用來減輕抗壞血酸過氧化物酶(ascorbate peroxidase)基底的氧化應力(oxidative stress)。[3]還有許多重要的生物合成過程中也需要維生素C參與作用。 ... into ascorbate in the mammalian liver. This liver metabolite, ascorbate, is produced in an unstressed goat for instance, at the ... Effect of ascorbate deficiency on the in situ activity of gammabutyrobetaine hydroxylase. J Biol Chem 259:10764-10770, 1984. ... Proctor
... an Anglo-Dutch energy exchange Ascorbate peroxidase, an antioxidant enzyme. Atari Program Exchange, an early computer software ...
One of these proximity labeling approaches is the ascorbate peroxidase (APEX) method, in which cells are engineered to express ... fused to a modified ascorbate peroxidase enzyme called APEX. Upon incubating the cells in biotin and treating the cells with ...
H2O2 is reduced to water by ascorbate peroxidase (APX) using ascorbate as the electron donor. The oxidized ascorbate ( ... Antioxidant Oxidative stress Peroxidases Noctor G, Foyer CH (Jun 1998). "ASCORBATE AND GLUTATHIONE: Keeping Active Oxygen Under ... Nevertheless, other enzymes (peroxidases) including peroxiredoxins and glutathione peroxidases, which use thioredoxins or ... ascorbate and NADPH are present in high concentrations in plant cells it is assumed that the glutathione-ascorbate cycle plays ...
Animal heme-dependent peroxidases Ascorbate peroxidase Catalase Chloride peroxidase Cytochrome c peroxidase Glutathione ... A majority of peroxidase protein sequences can be found in the PeroxiBase database. Peroxidase can be used for treatment of ... Peroxidases are sometimes used as histological marker. Cytochrome c peroxidase is used as a soluble, easily purified model for ... The glutathione peroxidase family consists of 8 known human isoforms. Glutathione peroxidases use glutathione as an electron ...
"Ascorbate peroxidase". 2: 139-153. Welinder KG (1991). "Bacterial catalase-peroxidases are gene duplicated members of the plant ... peroxidases, exhibiting both peroxidase and catalase activities. It is thought that catalase-peroxidase provides protection to ... Haem peroxidases (or heme peroxidases) are haem-containing enzymes that use hydrogen peroxide as the electron acceptor to ... Another family of haem peroxidases is the DyP-type peroxidase family. Nelson RE, Fessler LI, Takagi Y, Blumberg B, Keene DR, ...
... (or APX) is a member of the family of heme-containing peroxidases. Heme peroxidases catalyse the H2O2- ... Cytochrome c peroxidase Manganese peroxidase Kelly GJ, Latzko E (1979). "Soluble ascorbate peroxidase: detection in plants and ... ascorbate peroxidases is a class I peroxidase enzyme. APXs catalyse the H2O2-dependent oxidation of ascorbate in plants, algae ... Sharp, KH; Mewies, M; Moody, PCE; Raven, EL (2003). "Crystal structure of the ascorbate peroxidase-ascorbate complex" (PDF). ...
L-ascorbic acid-specific peroxidase, ascorbate peroxidase, and ascorbic acid peroxidase. This enzyme participates in ascorbate ... In enzymology, a L-ascorbate peroxidase (EC 1.11.1.11) is an enzyme that catalyzes the chemical reaction L-ascorbate + H2O2 ... Shigeoka S, Nakano Y, Kitaoka S (1980). "Metabolism of hydrogen peroxide in Euglena gracilis Z by L-ascorbic acid peroxidase". ... Shigeoka S, Nakano Y, Kitaoka S (1980). "Purification and some properties of L-ascorbic-acid-specific peroxidase in Euglena ...
CCP has high sequence identity to the closely related ascorbate peroxidase enzyme. Altchul, A. M., Abrams, R., and Hogness, T. ... Cytochrome c peroxidase, or CCP, is a water-soluble heme-containing enzyme of the peroxidase family that takes reducing ... Cytochrome c peroxidase, maintained by the Kraut Research Group. The UniProt entry for yeast cytochrome c peroxidase. Molecular ... Much like catalase, the reaction of cytochrome c peroxidase proceeds through a three-step process, forming first a Compound I ...
ISBN 978-1-57881-199-1. CS1 maint: Uses editors parameter (link) Wefers H, Sies H; Sies (1988). "The protection of ascorbate ... alpha-Tocopherol is a lipid-soluble antioxidant functioning within the glutathione peroxidase pathway, and protecting cell ... such as ascorbate, retinol or ubiquinol. Other forms of vitamin E have their own unique properties; for example, γ-tocopherol ...
Glutathione-ascorbate cycle Antioxidant Meister A, Anderson ME (1983). "Glutathione". Annual Review of Biochemistry. 52: 711-60 ... Antioxidant enzymes, such as glutathione peroxidases and peroxiredoxins, generate glutathione disulfide during the reduction of ...
The glutathione-ascorbate cycle, which works to detoxify hydrogen peroxide (H2O2), is one very specific example of this ... Glutathione has multiple functions: It maintains levels of reduced glutaredoxin and glutathione peroxidase. It is one of the ... It is a pivotal component of the glutathione-ascorbate cycle, a system that reduces poisonous hydrogen peroxide. It is the ... Glutathione (GSH) participates in leukotriene synthesis and is a cofactor for the enzyme glutathione peroxidase. It is also ...
Electron donors may include ascorbate, cytochrome b5 or ferredoxin reductase. The catalytic NO dioxygenation can be written in ... and peroxidase. NODs, as well as many hemoglobins that function as NODs, are distributed to most life forms including bacteria ...
In plants, vitamin C is a substrate for ascorbate peroxidase. This enzyme utilizes ascorbate to neutralize toxic hydrogen ... Ascorbate salts such as sodium ascorbate and calcium ascorbate are used in some dietary supplements. These release ascorbate ... However, taking vitamin C in the form of sodium ascorbate and calcium ascorbate may minimize this effect.[29] Other symptoms ... The most commonly used supplement compounds are ascorbic acid, sodium ascorbate and calcium ascorbate.[2] Vitamin C molecules ...
Thylakoid-bound ascorbate peroxidase had a high similarity to cytosolic ascorbate peroxidases, and the precursor contained a ... Thylakoid-bound ascorbate peroxidase had a high similarity to cytosolic ascorbate peroxidases, and the precursor contained a ... Keywords: Ascorbate peroxidase (EC 1.11.1.11); Chloroplasts; Oxidative stress; Putative membrane-spanning domain; Thylakoid- ... A cDNA for thylakoid-bound ascorbate peroxidase of pumpkin was cloned and characterized. ...
... * ... In this study, we demonstrate that in the absence of the cytosolic H2O2-scavenging enzyme ascorbate peroxidase 1 (APX1), the ...
... peroxisomal membrane-bound ascorbate peroxidase. Ascorbate peroxidases are important defense enzymes that protect plant cells ... Cloning and expression of an Arabidopsis gene encoding a putative peroxisomal ascorbate peroxidase.. ...
Sharp KH, Mewies M, Moody PCE & Raven EL (2003) Crystal structure of the ascorbate peroxidase-ascorbate complex. Nat Struct ... In ascorbate peroxidase, for example, (hydrophobic) aromatic substrates and (hydrophilic) ascorbate are oxidized at different ... Subsequent structures for the ascorbate peroxidase-ascorbate complex [8] and for nitric oxide synthase in complex with its ... Lad L, Mewies M, Basran J, Scrutton NS & Raven EL (2002) Role of histidine 42 in ascorbate peroxidase - kinetic analysis of the ...
Ascorbate peroxidase (or APX) is a member of the family of heme-containing peroxidases. Heme peroxidases catalyse the H2O2- ... Cytochrome c peroxidase Manganese peroxidase Kelly GJ, Latzko E (1979). "Soluble ascorbate peroxidase: detection in plants and ... ascorbate peroxidases is a class I peroxidase enzyme. APXs catalyse the H2O2-dependent oxidation of ascorbate in plants, algae ... Sharp, KH; Mewies, M; Moody, PCE; Raven, EL (2003). "Crystal structure of the ascorbate peroxidase-ascorbate complex" (PDF). ...
L-ascorbic acid-specific peroxidase, ascorbate peroxidase, and ascorbic acid peroxidase. This enzyme participates in ascorbate ... In enzymology, a L-ascorbate peroxidase (EC 1.11.1.11) is an enzyme that catalyzes the chemical reaction L-ascorbate + H2O2 ... Shigeoka S, Nakano Y, Kitaoka S (1980). "Metabolism of hydrogen peroxide in Euglena gracilis Z by L-ascorbic acid peroxidase". ... Shigeoka S, Nakano Y, Kitaoka S (1980). "Purification and some properties of L-ascorbic-acid-specific peroxidase in Euglena ...
A major hydrogen peroxide detoxifying system in plant cells is the ascorbate-glutathione cycle, in which, ascorbate peroxidase ... CAT (catalase), SOD (Superoxide dismutase), GPX (Gluthatione peroxidase) and APX (Ascorbate peroxidase) enzymes, Reactive ... Plant responses to stresses: Role of ascorbate peroxidase in the antioxidant protection.. Caverzan A1, Passaia G, Rosa SB, ... Plant responses to stresses: Role of ascorbate peroxidase in the antioxidant protection ...
Ascorbate peroxidase (APXs) plays an important role in the anti-oxidant system by utilizing AsA as specific electron donor to ... Antisense-mediated suppression of tomato thylakoidal ascorbate peroxidase influences anti-oxidant network during chilling ... thylakoidal ascorbate peroxidase gene (LetAPX) was isolated and antisense transgenic tomato plants were produced. Under ... On the other hand, after chilling stress, transgenic plants showed higher reduced ascorbate (AsA) and activities of catalase ( ...
... This review summarizes the most recent advances in our understanding of the haem enzyme ascorbate peroxidase. The aim is to ... more well-characterized peroxidases (in particular cytochrome c peroxidase). It contains 212 references and covers literature ...
Peroxidases that utilize ASCORBIC ACID as an electron donor to reduce HYDROGEN PEROXIDE to WATER. The reaction results in the ... Ascorbate Peroxidases. Known as: Ascorbate Peroxidase, Peroxidases, Ascorbate, Acid Peroxidase, L-Ascorbic (More). ... Regulation and function of ascorbate peroxidase isoenzymes.. *Shigeru Shigeoka, Takahiro Ishikawa, +4 authors Kazuya Yoshimura ... Ascorbate peroxidases are haem proteins that efficiently scavenge H2O2 in the cytosol and chloroplasts of plants. Database… ( ...
... bacterial peroxidase superfamily, together with yeast cytochrome c peroxidase and ascorbate peroxidases. Obviously these ... Catalase-peroxidases belong to Class I of the plant, fungal, ... phylogeny of catalase-peroxidases and ascorbate peroxidases ... bacterial peroxidase superfamily, together with yeast cytochrome c peroxidase and ascorbate peroxidases. Obviously these ... The overall structure of eukaryotic Class I peroxidases may be retained in both halves of catalase-peroxidases, with major ...
Peroxidase-catalyzed oxidation of ascorbate: structural, spectroscopic and mechanistic correlations in ascorbate peroxidase ... Leishmania major encodes an unusual peroxidase that is a close homologue of plant ascorbate peroxidase: a novel role of the ... Recent advances in ascorbate biosynthesis and the physiological significance of ascorbate peroxidase in photosynthesizing ... Substrate binding and catalytic mechanism in ascorbate peroxidase: evidence for two ascorbate binding sites ...
Wheat Stripe Rust Resistance Protein WKS1 Reduces the Ability of the Thylakoid-Associated Ascorbate Peroxidase to Detoxify ... Wheat Stripe Rust Resistance Protein WKS1 Reduces the Ability of the Thylakoid-Associated Ascorbate Peroxidase to Detoxify ... WKS1.1 is targeted to the chloroplast where it phosphorylates the thylakoid-associated ascorbate peroxidase (tAPX) and reduces ...
Ascorbate peroxidase is a bifunctional peroxidase that catalyzes the H(2)O(2)-dependent oxidation of both ascorbate and various ... Crystal structure of the ascorbate peroxidase-salicylhydroxamic acid complex.. Authors: Sharp, KH. Moody, PC. Brown, KA. Raven ... The structure provides the first information about the location of the aromatic binding site in ascorbate peroxidase and, ... 10, 303-307]. In this work, the X-ray crystal structure of recombinant soybean cytosolic ascorbate peroxidase (rsAPX) in ...
... for ascorbate peroxidase and guaiacol peroxidase and for the chloroplastic and cytosolic isozymes of ascorbate peroxidase in ... 1993) Detection of ascorbate peroxidase activity in native gels by inhibition of the ascorbate-dependent reduction of nitroblue ... 1996) Inactivation mechanism of ascorbate peroxidase at low concentrations of ascorbate: Hydrogen peroxide decomposes compound ... 1987) Purification of ascorbate peroxidase in spinach chloroplasts: its inactivation in ascorbate-depleted medium and ...
"Cloning and expression of an Arabidopsis gene encoding a putative peroxisomal ascorbate peroxidase, Plant Molecular Biology" on ... peroxidase. Ascorbate peroxidases are important defense enzymes that protect plant cells from oxidative stress ... was identified as a putative peroxisomal membrane-bound ascorbate peroxidase. Ascorbate peroxidases are important defense ... was identified as a putative peroxisomal membrane-bound ascorbate peroxidase. Ascorbate peroxidases are important defense ...
"Reactive oxygen intermediates and glutathione regulate the expression of cytosolic ascorbate peroxidase during iron-mediated ... Expression of spinach ascorbate peroxidase isoenzymes in response to oxidative stresses. Yoshimura, K.; Yabuta, Y.; Ishikawa, T ... Regulation of pea cytosolic ascorbate peroxidase and other antioxidant enzymes during the progression of drought stress and ... Control of the appearance of ascorbate peroxidase (EC 1.11.1.11) in mustard seedling cotyledons by phytochrome and ...
... ascorbate peroxidase; Asc, ascorbate; DHA, dehydroascorbate; DHAR, dehydroascorbate reductase; GAPDH, NADP+-glyceraldehyde 3- ... Keywords: Active oxygen; Ascorbate peroxidase (APX); Chloroplasts; Hydrogen peroxide -- Transplastomic tobacco; Water-water ... Concomitant with the O2 uptake, both ascorbate peroxidase (APX) and glyceraldehyde 3-phosphate dehydrogenase (GAPDH) lost their ... Concomitant with the O2 uptake, both ascorbate peroxidase (APX) and glyceraldehyde 3-phosphate dehydrogenase (GAPDH) lost their ...
2.7.4. Ascorbate Peroxidase (APX) Activity. An aliquot of 0.5 g of leaves was extracted in 3 mL of phosphate buffer (50 mM, pH ... Nakano, Y.; Asada, K. Hydrogen peroxide is scavenged by ascorbate-specific peroxidase in spinach chloroplasts. Plant Cell ... A mixture of 1.5 mL phosphate buffer (50 mM, pH 7.0), 300 μL ascorbate (0.05 mM), 600 μL H2O2 (1 mM), and 600 μL of plant ... Dalton, D.A.; Russell, S.A.; Hanus, F.; Pascoe, G.A.; Evans, H.J. Enzymatic reactions of ascorbate and glutathione that prevent ...
Chemical, spectroscopic and structural investigation of the substrate-binding site in ascorbate peroxidase ... spectroscopic and structural investigation of the substrate-binding site in ascorbate peroxidase. The FEBS Journal, 248(2), pp ...
Activity of ascorbate peroxidase (APX) (A), glutathione reductase (GR) (B), dehydroascorbate reductase (DR) (C), and ... Figure 7: Activity of ascorbate peroxidase (APX) (A), glutathione reductase (GR) (B), dehydroascorbate reductase (DR) (C), and ... Figure 7: Activity of ascorbate peroxidase (APX) (A), glutathione reductase (GR) (B), dehydroascorbate reductase (DR) (C), and ... In addition, free ascorbate and total ascorbate content were significantly higher in roots treated with ASA under water stress ...
Oxidative stress related metabolites such as H2O2 and ROS scavenging enzymes like peroxidase (POD), ascorbate peroxidase (APX ... Ascorbate Peroxidase (APX). Activity of APX enzyme was assayed as described by Sarkar et al. (2014). The reaction mixture was ... Peroxidase (POD). Peroxidase activity assay was conducted as described by Singh and Jha (2016). Briefly, the phosphate buffer ( ... dependent oxidation of ascorbate was measured at 290 nm. ... and ascorbate (0.5 mM). The crude extract was added to the ...
Crystal structure of chloroplastic ascorbate peroxidase from tobacco plants and structural insights for its instability ... Wada, K. et al., Crystal structure of chloroplastic ascorbate peroxidase from tobacco plants and structural insights into its ... Crystal structure of chloroplastic ascorbate peroxidase from tobacco plants and structural insights for its instability. ...
Overexpression of Thylakoidal Ascorbate Peroxidase Drastically Reduces Induction of Genes in Paraquat-Treated Arabidopsis.. Our ... Because the activity of thylakoidal ascorbate peroxidase is confined to the chloroplast (14) and 1O2, because of its short half ... Overexpression of Thylakoidal Ascorbate Peroxidase Increases the Singlet Oxygen-Induced Whole-Plant Responses.. To investigate ... Overexpression of Thylakoidal Ascorbate Peroxidase Affects the Expression of Genes Induced During the Release of Singlet Oxygen ...
ASCORBATE PEROXIDASEProtoporphyrin Ix Containing FeSalicylhydroxamic AcidSodium Ion[dihydrogen 3,7,12,17-tetramethyl-8,13- ...
  • WKS1.1 is targeted to the chloroplast where it phosphorylates the thylakoid-associated ascorbate peroxidase (tAPX) and reduces its ability to detoxify peroxides. (jic.ac.uk)
  • In addition, free ascorbate and total ascorbate content were significantly higher in roots treated with ASA under water stress than those without ASA treatment. (nih.gov)
  • The total ascorbate content was lower, whereas accumulation of H 2 O 2 was higher in the vtc2-1 mutant than that in the wild type. (springer.com)