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PubMed1993

Molecular cloning, sequence analysis and expression of the gene for catalase-peroxidase (cpeA) from the photosynthetic bacterium Rhodobacter capsulatus B10.

The gene encoding catalase-peroxidase was cloned from chromosomal DNA of Rhodobacter capsulatus B10. The nucleotide sequence of a 3.7-kb SacI-HindIII fragment, containing the catalase-peroxidase gene (cpeA) and its flanking regions were determined. A 1728-bp open reading frame, coding for 576 amino acid residues (molecular mass 61516 Da) of the enzyme, was observed. A Shine-Dalgarno sequence was found 5 bp upstream from the translational start site. The deduced amino acid sequence coincides with that of the amino terminus and of four peptides derived from trypsin digestion of the purified catalase-peroxidase of R. capsulatus B10. The amino acid sequence of R. capsulatus catalase-peroxidase shows interesting similarities to the amino acid sequences of the hydroperoxidases of Escherichia coli (42.7%) and Salmonella typhimurium (39.9%), the peroxidase of Bacillus stearothermophilus (32.1%) and the catalase-peroxidase of Mycobacterium intracellulare (42.2%). As shown by a cpeA::lacZ fusion in trans in R. capsulatus, the expression of the catalase-peroxidase gene is regulated by oxygen. The promoter of the cpeA gene was localized within 320 bp upstream of the ATG start codon.

Amino Acid Sequence↗
PubMed2007

Structural motifs of syringyl peroxidases predate not only the gymnosperm-angiosperm divergence but also the radiation of tracheophytes.

* The most distinctive variation in the monomer composition of lignins in vascular land plants is that found between the two main groups of seed plants. Thus, while gymnosperm lignins are typically composed of guaiacyl (G) units, angiosperm lignins are largely composed of similar levels of G and syringyl (S) units. * However, and contrary to what might be expected, peroxidases isolated from basal (Cycadales and Ginkgoales) and differentially evolved (Coniferales and Gnetales) gymnosperms are also able to oxidize S moieties, and this ability is independent of the presence or absence of S-type units in their lignins. * The results obtained led us to look at the protein database to search for homologies between gymnosperm peroxidases and true eudicot S-peroxidases, such as the Zinnia elegans peroxidase. * The findings showed that certain structural motifs characteristic of eudicot S-peroxidases (certain amino acid sequences and beta-sheet secondary structures) predate the gymnosperm-angiosperm divergence and the radiation of tracheophytes, since they are found not only in peroxidases from basal gymnosperms, ferns and lycopods, but also in peroxidases from the moss Physcomitrella patens (Bryopsida) and the liverwort Marchantia polymorpha (Marchantiopsida), which, as typical of bryophytes, do not have xylem tissue nor lignins.

Amino Acid Motifs↗
PubMed1987

Peroxidases: past and present.

The history of peroxidases spans nearly two centuries. Our knowledge has developed from early phenomenological observations of the colored products of peroxidase-catalyzed reactions, to our present understanding of many of the steps in the complex peroxidation reaction mechanism. Peroxidases are ubiquitous in plant and animal tissues and occur in diverse structural forms. Collectively, they are able to catalyze the hydroperoxide oxidation of many different kinds of organic and inorganic compounds. In spite of the great diversity of structures and functions, mechanisms of heme-containing peroxidases have several common features: (i) the transfer of the oxidizing equivalents of the hydroperoxidase to the enzyme to form Compound I, (ii) the reduction of Compound I by the transfer of electrons from donor molecules, (iii) the inactivation of Compound I by excess hydroperoxide. Rate constants for these and other steps in the peroxidation mechanism, as well as redox potentials, have been reported for many peroxidases. The molecular basis for the donor specificity of peroxidases has not yet been elucidated. Today, much interest is directed towards the biological functions of peroxidases and their reaction products.

Chemistry↗
PubMed1995

Melatonin stimulates the activity of the detoxifying enzyme glutathione peroxidase in several tissues of chicks.

The pineal hormone melatonin has been shown to directly scavenge free radicals and to stimulate, in the mammalian brain, at least one enzyme, glutathione peroxidase, which reduces free radical generation. In the present studies, we examined the effect of melatonin on glutathione peroxidase activity in several tissues of an avian species. Melatonin (500 micrograms/kg), when injected into chicks, increased glutathione peroxidase activity within 90 min in every tissue examined. Tissue melatonin levels, measured by radioimmunoassay, also increased following its peripheral administration. Depending on the tissue, the measured increases in melatonin varied from 75% to 1,300% over the control values. The melatonin-induced increases in glutathione peroxidase activity varied with the tissue and were between 22% and 134%. These percentage increases in glutathione peroxidase activity were directly correlated with tissue melatonin content. These results suggest that melatonin induces the activity of the detoxifying enzyme, glutathione peroxidase, in several tissues in the chick. The findings also suggest that melatonin would reduce the generation of highly toxic hydroxyl radicals by metabolizing its precursor, hydrogen peroxide. Because of this ability to stimulate glutathione peroxidase activity, melatonin should be considered as a component of the antioxidative defense system in this avian species.

Animals↗
PubMed1978

Oxidation of Escherichia coli sulfhydryl components by the peroxidase-hydrogen peroxide-iodide antimicrobial system.

The chemical modification of bacterial components was studied following incubation of Escherichia coli with the peroxidase-hydrogen peroxide (H(2)O(2))-iodide (I(-)) antimicrobial system or with iodine (I(2)). The oxidation of cell sulfhydryls and the iodination of cell components were measured. Both the peroxidase system and I(2) oxidized sulfhydryls. When the I(-) concentration in the peroxidase system was greater than 100 muM, the peroxidase system and I(2) were equivalent. That is, sulfhydryl oxidation or killing per mole of H(2)O(2) equaled that per mole of I(2). These results were consistent with peroxidase-catalyzed oxidation of I(-) to yield 1 mol of I(2) per mol of H(2)O(2). Sulfhydryls were oxidized to yield sulfenic acids and free I(-). With I(-) concentrations in the range of 10 to 100 muM, the amount of sulfhydryls oxidized by the peroxidase system could exceed the amount of I(-). Because the oxidation of sulfhydryls to sulfenic acids did not consume I(-), one I(-) ion could participate in the oxidation of many sulfhydryls. With I(-) concentrations lower than 10 muM, complete oxidation of sulfhydryls was not obtained. Incorporation of I(-) into iodinated derivatives of bacterial components partly depleted the system of I(-) and limited the formation of I(2). These results indicated that antimicrobial activity was due to peroxidase-catalyzed oxidation of I(-) to I(2), followed by I(2) oxidation of cell components. There was a direct relationship between sulfhydryl oxidation and antimicrobial action. Although iodination of bacterial components accompanied sulfhydryl oxidation, the amount of I(-) incorporation was not directly related to antimicrobial action. Also, incorporation of I(-) interfered with antimicrobial action at low I(-) concentrations.

Escherichia coli↗
PubMed1997

Stabilization of lignin peroxidases in white rot fungi by tryptophan.

Supplementation of various cultures of white rot fungi with tryptophan was found to have a large stimulatory effect on lignin peroxidase activity levels. This enhancement was greater than that observed in the presence of the lignin peroxidase recycling agent veratryl alcohol. Using reverse transcription-PCR, we found that tryptophan does not act to induce lignin peroxidase expression at the level of gene transcription. Instead, the activity enhancement observed is likely to result from the protective effect of tryptophan against H2O2 inactivation. In experiments using a partially purified lignin peroxidase preparation, tryptophan and its derivative indole were determined to function in the same way as veratryl alcohol in converting compound II, an oxidized form of lignin peroxidase, to ferric enzyme, thereby completing the catalytic cycle. Furthermore, tryptophan was found to be a better substrate for lignin peroxidase than veratryl alcohol. Inclusion of either tryptophan or indole enhanced the oxidation of the azo dyes methyl orange and Eriochrome blue black. Stimulation of azo dye oxidations by veratryl alcohol has previously been shown to be due to its enzyme recycling function. Our data allow us to propose that tryptophan stabilizes lignin peroxidase by acting as a reductant for the enzyme.

Azo Compounds↗
PubMed1986

Sea urchin sperm peroxidase is competitively inhibited by benzohydroxamic acid and phenylhydrazine.

Sea urchin sperm contain a phenylhydrazine-sensitive peroxidase that is believed to use hydrogen peroxide produced by the fertilized egg to reduce sperm fertility and thereby assist in the prevention of polyspermy. Strongylocentrotus purpuratus sperm were treated initially with hypotonic phosphate buffer (pH 7.0) to remove catalase and then extracted with 0.5% Triton X-100 in 0.5 M acetate buffer (pH 5.0). Peroxidase activity in this detergent extract was assayed using 3,3',5,5'-tetramethyl benzidine (TMB) as oxidizable substrate. Kinetic studies showed that the Km for TMB is 250 microM. Benzohydroxamic acid and phenylhydrazine are known to be competitive inhibitors of a variety of plant and animal peroxidases. These substances were found to competitively inhibit the sea urchin sperm peroxidase: for benzohydroxamic acid, Ki = 51.2 microM, mean inhibitory dose (ID50) = 146.7 microM; for phenylhydrazine, Ki = 201 nM, ID50 = 303 nM. These findings indicate that the biochemical properties of the sea urchin sperm peroxidase resembles those of peroxidases found in somatic tissues where oxygen radicals are produced by phagocytes to kill bacteria and support our hypothesis that the sperm peroxidase has a functional role in the prevention of polyspermy during fertilization.

Animals↗
PubMed1982

Increased neutrophil peroxidase activity in acute myeloid leukaemia.

A case of acute myeloid leukaemia (AML) (M2 type) is described in which the neutrophil population contained markedly increased peroxidase activity. The increased peroxidase activity was initially detected during routine counting with the Hemalog D automated differential counter and the increased enzyme staining was confirmed by manual and ultrastructural cytochemistry. The abnormal neutrophil population persisted after blast cells had disappeared from the blood and until marrow hypoplasia was induced by chemotherapy. When remission emerged, the peroxidase activity of the neutrophil population was normal. At subsequent relapse, the neutrophil population with increased peroxidase activity reappeared and with the induction of second remission neutrophil peroxidase again returned to normal. In 8 other cases where sufficient neutrophils were present for analysis by the Hemalog D, neutrophil peroxidase was normal or not increased in 7 cases, but was markedly reduced in 1 case of AML (M6 type). It is suggested that abnormalities of neutrophil peroxidase activity detected by the Hemalog D may serve as useful leukaemic markers.

Bone Marrow↗
PubMed1982

Role for endogenous and acquired peroxidase in the toxoplasmacidal activity of murine and human mononuclear phagocytes.

Oxygen products generated by the respiratory burst of mononuclear phagocytes are microbicidal to intracellular pathogens including Toxoplasma gondii. The toxicity of one of these products, H(2)O(2), is markedly amplified by the granule peroxidase of circulating phagocytes in the presence of a halide. Eosinophil peroxidase (EPO) binds firmly to the surface of T. gondii and such organisms remain viable as determined by vital staining, uptake of 2-deoxyglucose, and survival and replication in human fibroblasts. They are, however, rapidly killed by the addition of H(2)O(2) and iodide under conditions in which control organisms are unaffected. We have used EPO bound to T. gondii to explore the role of peroxidase in the toxoplasmacidal activity of mononuclear phagocytes. Resident mouse peritoneal macrophages lack a granule peroxidase and have a weak respiratory burst; toxoplasma survive and replicate within these cells. However, these cells acquire significant toxoplasmacidal activity, as assessed microscopically and by the inhibition of uracil uptake, when organisms are coated with EPO before ingestion, an effect which is decreased by the hemeprotein inhibitors, aminotriazole and azide. EPO on the surface of Toxoplasma does not increase their ingestion by macrophages or the associated respiratory burst. Monocytes from patients with hereditary myeloperoxidase deficiency have a significant toxoplasmacidal defect that is abolished when EPO-coated organisms are used. In contrast, the toxoplasmacidal defect of monocytes from chronic granulomatous disease patients is unaffected by surface-bound EPO. In these studies, replication of surviving intracellular organisms varied inversely with the magnitude of the respiratory burst: replication was greatest in fibroblasts, slightly less in resident macrophages, and least in monocytes; it was significantly greater in chronic granulomotous disease than in normal or myeloperoxidase-deficient monocytes. These studies support a role for oxygen products and endogenous peroxidase in the optimal killing of T. gondii by monocytes and demonstrate that peroxidase-negative phagocytes can utilize peroxidase on the surface of ingested organisms to augment microbicidal activity.

Animals↗
PubMed1983

Characterization of a human blood monocyte subset with low peroxidase activity.

Two human monocyte subsets from the peripheral blood of healthy donors have been isolated in greater than 90% purity by countercurrent centrifugal elutration and human serum albumin gradients and their functional capabilities have been assessed. We have demonstrated that one subset ("regular" monocytes, RM) showed intense cytoplasmic peroxidase staining and contained substantial peroxidase activity. In contrast, another subset ("intermediate" monocytes, IM) stained poorly for peroxidase and had low peroxidase activity. By electron microscopic analysis combined with peroxidase localization, it was found that IM had fewer peroxidase-positive granules per cell than did RM. IM coelutriated with some lymphocytes and by cell sizing analysis were shown to be slightly smaller than RM. Functional and cytochemical analysis of these subsets indicated that IM had less activity than RM in assays such as accessory cell function for mitogen-induced T lymphocyte proliferation and antibody-dependent cellular cytotoxicity, and that fewer IM expressed OKM1 antigen and pokeweed mitogen (PWM) receptors on their membranes than did RM. The subset of IM not bearing either the PWM receptor or the OKM1 antigen had very low peroxidase activity. IM also were found to have a greater sensitivity to polyriboinosinic and polyribocytidilic acid (100 micrograms/ml)-induced secretion of interferon. There was no significant difference in the phagocytic capability, the percentage of Fc receptor-positive cells, 5'-nucleotidase activity, DR antigen expression, or the responsiveness to migration inhibitory factor of IM as compared with RM. Furthermore, it was found that the ratio of IM to RM increased after prolonged cytapheresis, which suggests that IM are more mobilizable than RM from the extravascular reservoirs of human monocytes.

Adult↗
PubMed1983

An evaluation of peroxidase as a marker for estrogen action in normal mammary glands of mice.

The present studies were initiated to study peroxidase and its possible regulation by estrogen in normal mammary glands. The activity of peroxidase was measured biochemically using guaiacol as the substrate for oxidation. Significant levels of peroxidase activity were associated with the particulate fraction of mammary glands from virgin mice, pregnant mice, and mice undergoing lactational involution. However, during lactation there was no detectable level of peroxidase activity in the mammary glands. Although ovariectomy led to a decrease in mammary peroxidase, detailed studies using various hormonal manipulations revealed that mammary peroxidase was perhaps not a product of estrogen action alone, but might be the result of a complex hormonal control related to growth. Alternatively, a critical evaluation of all of the data obtained with mammary glands and a comparison of these data obtained with the uterus also suggest that the presence of peroxidase in mammary glands may be due to infiltration of eosinophils and macrophages in these tissues resulting from mast cell degranulation.

Animals↗
PubMed1995

Cloning, sequencing, and heterologous expression of a gene coding for Arthromyces ramosus peroxidase.

To understand the relationship between the structure and functions of the peroxidase of Arthromyces ramosus, a novel taxon of hyphomycete, and the evolutionary relationship of the A.ramosus peroxidase (ARP) with the other peroxidases, we isolated complementary and genomic DNA clones encoding ARP and characterized them. The sequence analyses of the ARP and cDNA coding for ARP showed that a mature ARP consists of 344 amino acids with a N-terminal pyroglutamic acid preceded by a signal peptide of 20 amino acid residues. The amino acid sequence of ARP was 99% identical to that of the peroxidase of Coprinus cinereus, a basidiomycete, and also had very high similarities (41-43% identity) to those of basidiomycetous lignin peroxidases, although we could find no lignin peroxidase activities for ARP when assayed with lignin model compounds. We could identified His184 and His56 as proximal and distal ligands to heme, respectively, and Arg52 as an essential Arg. Comparison of the sequences of complementary and genomic DNAs found that protein-encoding DNA is interrupted by 14 intervening sequences. The ARP cDNA was expressed in the yeast Saccharomyces cerevisiae under the promoter of the glyceraldehyde 3-phosphate dehydrogenase gene, yielding 0.02 units/ml of a secreted active peroxidase.

Base Sequence↗
PubMed2001

Radiosensitivity of mammalian cell lines engineered to overexpress cytosolic glutathione peroxidase.

Reactive oxygen species are believed to be involved in radiation lethality. Glutathione peroxidase is an intracellular enzyme with antioxidant functions. To determine whether increasing the cellular antioxidant capacity can confer radiation resistance, the effect of overexpression of glutathione peroxidase on radiosensitivity was determined in two different cell types. An expression construct including the bovine cytosolic glutathione peroxidase cDNA was used to overexpress this enzyme in cells of the human lymphoblast cell line Sup-T1 as well as the Chinese hamster ovary cell line AA8. Supplementation of the culture media with 30 nM sodium selenite was included to obtain optimal glutathione peroxidase activity. Northern blot analysis confirmed the presence of the construct mRNA, and a standard coupled spectrophotometric assay demonstrated significantly increased glutathione peroxidase activity in the transfected cell lines. An approximately 8-fold increase was found in the Sup-T1 cells, and an approximately 30-fold increase was obtained in the Chinese hamster ovary AA8 cells. Clonogenic survival was assayed in the overexpressing cells and compared to that in control cells transfected with vector alone. Despite significantly increased glutathione peroxidase activity, no observable radioprotection was conferred in either of the two cell lines studied, indicating that increased glutathione peroxidase activity is insufficient to confer radioresistance in the two cell types examined. These data are discussed in the context of using antioxidants as adjuncts to clinical radiotherapy.

Animals↗
PubMed2001

Molecular cloning, sequencing analysis and expression of the catalase-peroxidase gene from Halobacterium salinarum.

The gene encoding catalase-peroxidase was cloned from chromosomal DNA from the Archaea, Halobacterium salinarum. The nucleotide sequence of a 3.5 kb fragment, containing the catalase-peroxidase gene and its flanking regions was determined. A 2.16 kb open reading frame was obtained, encoding the enzyme which was comprised of 720 amino acid residues with a calculated molecular weight of 80 kDa. The deduced amino acid sequence of the H. salinarum catalase-peroxidase showed a high degree of identity to other bifunctional catalase-peroxidases. A transcriptional start site was identified 183 bp upstream of the translational start codon. Southern blot analysis indicated that catalase-peroxidase was a single copy gene. The Archaeal catalase-peroxidase gene was expressed in Escherichia coli, and the expressed fusion protein exhibited both catalase and peroxidase activities.

Amino Acid Sequence↗
PubMedDate not supplied

[Oxidative destruction of estradiol after treatment with hydrogen peroxide catalyzed by horseradish peroxidase and methemoglobin].

It is shown that estradiol in the presence of horse radish peroxidase interacts with hydrogen peroxide, which is evidenced by an increase in its optical density at 280 nm. The photometering of samples containing estradiol and horse radish peroxidase upon their titration with hydrogen peroxide indicated that the increase in optical density stops after introducing hydrogen peroxide equimolar in concentration to estradiol. The stoichiometric ratio of estradiol consumed during oxidative destruction to hydrogen peroxide was 1:1. In the presence of ascorbate, the oxidative destruction of estradiol by the action of hydrogen peroxide, catalyzed by horse radish peroxidase, was observed only after a latent period and showed the same regularities as in the absence of ascorbate. It was found by calorimetry that, during the latent period, estradiol catalyzes the degradation of hydrogen peroxide and ascorbate without undergoing oxidative destruction. The substrates of the peroxidase reaction benzidine, 1-naphthol, and phenol interact with hydrogen peroxide in the presence of ascorbate and horse radish peroxidase in a similar way. Presumably, upon interaction with hydrogen peroxide in the presence of horse radish peroxidase, estradiol, like other substrates of this reaction, undergoes oxidative destruction by the mechanism of peroxidase reaction. It is shown that oxidative destruction of estradiol by the action of hydrogen peroxide can also be catalyzed by methemoglobin by the same mechanism. These data are important for understanding the role of estradiol in the organism and the pathways of its metabolic conversions.

Catalysis↗
PubMed2000

Lacrimal fluid peroxidase activity during the menstrual cycle.

PURPOSE: The aim of this work was to investigate peroxidase activity in human tears during the various phases of the menstrual cycle. For comparative purposes saliva was also examined. METHODS: Tear fluids and saliva from 10 healthy volunteers 23-41 years of age (mean: 28.2 years), with regular menstrual cycles were sampled for the duration of at least two complete cycles. Menstrual cycles and ovulation periods were evaluated by measuring morning body temperature and hormone levels in plasma and urine. Unstimulated tears and unstimulated saliva were collected in the morning every two days. Peroxidase activity was monitored according to the 5,5'-dithiobis, 2-nitrobenzoic acid thiocyanate (Nbs-SCN) method and the protein content was determined by the Bradford method. RESULTS: Peroxidase activity in tears, expressed as U/mL, was significantly (p <.05) higher during the preovulatory and luteal phases with respect to the menses, whilst total protein content remained almost unchanged throughout all phases. A positive correlation was found between lacrimal fluid peroxidase activity and 17beta-estradiol plasma levels (p <.001). Salivary peroxidase activity did not show such estrogen-related changes. CONCLUSIONS: Our findings report cyclic variations in peroxidase activity in human tears during the menstrual cycle. Such cycling seems to reflect variations of 17 beta-estradiol plasma levels. These results suggest that a regulation of lacrimal fluid peroxidase by 17 beta-estradiol could be one possible cause for the female gender predilection in some ocular diseases, such as keratoconjunctivitis sicca.

Adult↗
PubMed2000

Mechanism of peroxidase actions for salicylic acid-induced generation of active oxygen species and an increase in cytosolic calcium in tobacco cell suspension culture.

Extracellularly secreted peroxidases in cell suspension culture of tobacco (Nicotiana tabacum L. cv. Bright Yellow-2, cell line BY-2) catalyse the salicylic acid (SA)-dependent formation of active oxygen species (AOS) which, in turn, triggers an increase in cytosolic Ca2+ concentration. Addition of horseradish peroxidase (HRP) to tobacco cell suspension culture enhanced the SA-induced increase in cytosolic Ca2+ concentration, suggesting that HRP enhanced the production of AOS. The mechanism of peroxidase-catalysed generation of AOS in SA signalling was investigated with chemiluminescence sensitive to AOS and electron spin resonance (ESR) spectroscopy, using the cell suspension culture of tobacco, and HRP as a model system of peroxidase reaction. The results showed that SA induced the peroxidase inhibitor-sensitive production of superoxide and H2O2 in tobacco suspension culture, but no production of hydroxy radicals was detected. Similar results were obtained using HRP. It was also observed that SA suppressed the H2O2-dependent formation of hydroxy radicals in vitro. The results suggest that SA protect the cells from highly reactive hydroxy radicals, while producing the less reactive superoxide and H2O2 through peroxidase-catalysed reaction, as the intermediate signals. The formation of superoxide was followed by that of H2O2, suggesting that superoxide was converted to H2O2. In addition, it was observed that superoxide dismutase-insensitive ESR signal of monodehydroascorbate radical was induced by SA both in the tobacco suspension culture and HRP reaction mixture, suggesting that SA free radicals, highly reactive against ascorbate, were formed by peroxidase-catalysed reactions. The formation of SA free radicals may lead to subsequent monovalent reduction of O2 to superoxide.

Calcium↗
PubMed2001

Rapid deposition of extensin during the elicitation of grapevine callus cultures is specifically catalyzed by a 40-kilodalton peroxidase.

Elicitation or peroxide stimulation of grape (Vitis vinifera L. cv Touriga) vine callus cultures results in the rapid and selective in situ insolubilization of an abundant and ionically bound cell wall protein-denominated GvP1. Surface-enhanced laser desorption/ionization/time of flight-mass spectrometry analysis, the amino acid composition, and the N-terminal sequence of purified GvP1 identified it as an 89.9-kD extensin. Analysis of cell walls following the in situ insolubilization of GvP1 indicates large and specific increases in the major amino acids of GvP1 as compared with the amino acids present in salt-eluted cell walls. We calculate that following deposition, covalently bound GvP1 contributes up to 4% to 5% of the cell wall dry weight. The deposition of GvP1 in situ requires peroxide and endogenous peroxidase activity. Isoelectric focusing of saline eluates of callus revealed only a few basic peroxidases that were all isolated or purified to electrophoretic homogeneity. In vitro and in situ assays of extensin cross-linking activity using GvP1 and peroxidases showed that a 40-kD peroxidase cross-linked GvP1 within minutes, whereas other grapevine peroxidases had no significant activity with GvP1. Internal peptide sequences indicated this extensin peroxidase (EP) is a member of the class III peroxidases. We conclude that we have identified and purified an EP from grapevine callus that is responsible for the catalysis of GvP1 deposition in situ during elicitation. Our results suggest that GvP1 and this EP play an important combined role in grapevine cell wall defense.

Adaptation, Physiological↗