Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound   Target Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound

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Query: EC:3.2.1.15 (pectinase)
2,440 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Ethylene-induced abscission in leaf and fruit explants of peach involves different enzymes. In leaves abscission is accompanied by increased occurrence of cellulase forms differing in isoelectric point (pI 6.5 and 9.5). A polypeptide with a molecular mass of 51 kDa gives in a western blot a strong cross-reaction with an antibody raised against a maturation cellulase from avocado fruit. Cellulase activity is also found in abscising fruit explants but the amount is very low compared to that of the leaf explants. A northern analysis with a cellulase clone from avocado reveals the presence of two hybridizing mRNAs with a size of 2.2 kb and 1.8 kb, respectively. The steady-state level of the 2.2 kb mRNA is significantly increased by treatment with ethylene. Polygalacturonases are not detected in abscising leaves, but are strongly induced by ethylene in fruit explants. Of the three forms found, two are exopolygalacturonases while the third is an endoenzyme. Ethylene activates preferentially the endoenzyme and the basic exoenzyme but depresses the acid exopolygalacturonases. A northern analysis carried out with a cDNA coding for tomato endopolygalacturonase shows hybridization only with one endopolygalacturonase mRNA form in the fruit abscission zone. Treatment with ethylene causes an increase in the steady-state level of this mRNA. The differences in the enzyme patterns observed in fruit and leaf abscission zones and a differential enzyme induction suggest the feasibility to regulate fruit abscission in peach with the aid of antisense RNA genes.
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PMID:Cellulase and polygalacturonase involvement in the abscission of leaf and fruit explants of peach. 128 37

A new method for detecting enzymes produced by fungal spores during germination is described here. With this method, the production of enzymes such as protease, cellulase, or pectinase can be correlated with the extent of spore germination. Germination is studied in vitro on agar-based media containing protein, cellulose, or pectin. The spores are immobilized on a permeable membrane mounted on the substrate-containing medium. At various times after inoculation the membrane-bound spores are removed and the medium is stained. The extent of germination is assessed by microscopic examination of the spores and the presence of active hydrolytic enzymes is revealed by the staining. The staining methods are sensitive; detection limits are 1 X 10(-3) unit of cellulase; 2 X 10(-4) unit of protease; 3 X 10(-3) unit of pectin lyase; 3.5 units of polygalacturonase; 2 X 10(-3) unit of pectin methyl esterase. The method has been demonstrated by studying the production of enzymes by germinating conidia of Botrytis cinerea. Cellulase and protease were present before any spores germinated. Pectin lyase was first observed when at least 80% of the spores had germinated. Pectin methyl esterase and polygalacturonase were not produced by the spores.
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PMID:Plate assay for determining the time of production of protease, cellulase, and pectinases by germinating fungal spores. 391 30

Germlings of Botrytis cinerea, an important fungal pathogen of plants, produce an extracellular matrix (ECM), or ensheathing film, that serves, in part, in their attachment (R. P. Doss, et al., Appl. Environ. Microbiol. 61:260-265, 1995). The composition of this film has been ascertained by using samples obtained by growing germlings on a glass surface, removing the fungal mycelium by vigorous washing, and collecting the tightly attached film by scraping the substratum with a razor blade. Slightly over half of the dry weight of the ECM was found to be carbohydrates (about 20%), proteins (about 28%), and lipids (about 6%). Hydrolysis of the carbohydrate portion of the ECM revealed that glucose was the most prominent monosaccharide present, comprising about 60% of the total monosaccharides. Also present were mannose (about 35%) and myo-inositol (about 5%). The proteinaceous fraction of the ECM was made up of a number of polypeptides separable by polyacrylamide gel electrophoresis. The lipid fraction of the ECM, analyzed by thin-layer chromatography, was made up of several simple lipid components, including free fatty acid, mono- and triacylglycerol, wax ester, fatty alcohol, and several unidentified components. No complex lipids were detected. Isolated ECM exhibited polygalacturonase and laccase activity and was able to catalyze the hydrolysis of p-nitrophenyl butyrate, a model substrate for assessing cutinase activity. Cellulase, pectin lyase, and pectin methyl esterase activities were noted with both heated and unheated ECM preparations. Proteinase activity was not detected.
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PMID:Composition and enzymatic activity of the extracellular matrix secreted by germlings of botrytis cinerea. 992 60

We evaluated the effects of cellulase (from Trichoderma longibrachiatum) application rates on neutral detergent fiber (NDF) concentration and fermentation products of orchardgrass (Dactylis glomerata L.) and alfalfa (Medicago sativa L.) silages harvested with decreasing dry matter (DM) digestibility. Additionally, the impacts of inoculant (Lactobacillus plantarum and Pediococcus cerevisiae), pectinase (from Aspergillus niger), or formic acid on silage composition were studied. Forages wilted to a DM content of about 320 g/kg were ensiled in laboratory silos for 60 d. Cellulase, combined with inoculant, was applied at 2, 10, and 20 ml/kg of herbage (at least 2500 IU/ml). Cellulase at 10 ml/kg was also applied alone or in combination with pectinase and inoculant or formic acid. The NDF concentration of orchardgrass silage decreased with increasing cellulase up to 20 ml/kg, at which NDF content was decreased by 30%. The NDF concentration of alfalfa silage decreased with increasing cellulase application up to 10 ml/kg, at which NDF content was decreased by 13%. Immature plants were more responsive to cellulase treatment than mature plants. Cellulase at 2 ml/kg combined with inoculant improved fermentation characteristics of the silages but generally, there was no effect on silage fermentation by higher cellulase applications, resulting in an accumulation of sugar. The improved fermentation of orchardgrass treated with cellulase and inoculant was mostly related to the effect of inoculant, whereas cellulase alone improved fermentation characteristics of alfalfa silage and this effect was enhanced by addition of inoculant. Decreased NDF and increased sugar concentrations did not improve the in vitro DM digestibility of cellulase-treated silages.
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PMID:Enzyme, bacterial inoculant, and formic acid effects on silage composition of orchardgrass and alfalfa. 1090 57

Neutral xyloglucan was purified from the cell walls of suspension-cultured rose (Rosa sp. 'Paul's Scarlet') cells by alkali extraction, ethanol precipitation and anion-exchange chromatography on 'Q-Sepharose FastFlow'. The procedure recovered 70% of the total xyloglucan at about 95% purity in the neutral fraction. The remaining 30% of the xyloglucan was anionic, as demonstrated both by anion-exchange chromatography at pH 4.7 and by high-voltage electrophoresis at pH 6.5. Alkali did not cause neutral xyloglucan to become anionic, indicating that the anionic nature of the rose xyloglucan was not an artefact of the extraction procedure. Pre-incubation of neutral [3H]xyloglucan with any of ten non-radioactive acidic polysaccharides did not cause the radioactive material to become anionic as judged by electrophoresis, indicating that stable complexes between neutral xyloglucan and acidic polysaccharides were not readily formed in vitro. The anionic xyloglucan did not lose its charge in the presence of 8 M urea or after a second treatment with NaOH, indicating that its anionic nature was not due to hydrogen-bonding of xyloglucan to an acidic polymer. Proteinase did not affect the anionic xyloglucan, indicating that it was not associated with an acidic protein. Cellulase converted the anionic xyloglucan to the expected neutral nonasaccharide and heptasaccharide, indicating that the repeatunits of the xyloglucan did not contain acidic residues. Endo-polygalacturonase converted about 40% of the anionic xyloglucan to neutral material. Arabinanase and galactanase also converted appreciable proportions of the anionic xyloglucan to neutral material. These results show that about 30% of the xyloglucan in the cell walls of suspension-cultured rose cells exists in covalently-linked complexes with acidic pectins.
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PMID:Evidence for covalent linkage between xyloglucan and acidic pectins in suspension-cultured rose cells. 1094 22

Cellulase expressions in a normal shedding wild-type and a non-abscinding single gene mutant of Lupinus angustifolius have been studied during ethylene treatments of leaf abscission zone explants. Of the range of different glycohydrolases investigated only the abscission cell-specific beta-1,4-glucanhydrolase (cellulase) was not produced in the non-abscinding mutant. An endo-polygalacturonase was induced equally in both wild-type and mutant and other glycohydrolases were equally up-regulated. The abscission cell-specific cellulase induced at shedding of wild-type is antigenically similar to the Phaseolus vulgaris induced leaf abscission pI 9.5 cellulase but with a higher molecular mass (50 kD compared with 48 kD) and like the bean abscission-specific cellulase that of lupin is not glycosylated. Causes of the loss of function of cellulase expression in the non-shedding mutant are discussed.
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PMID:Failed expression of an endo-beta-1,4-glucanhydrolase (cellulase) in a non-abscinding mutant of Lupinus angustifolius cv Danja. 1173 Aug 65

Discs of avocado (Persea americana) fruit (15 x 3 mm thick) kept in a stream of moist air ripen within 72 h. Following cutting, a modest evolution of wound ethylene that dissipates in 24 h is followed by a burst of autocatalytic ethylene production associated with a respiratory climacteric, much as in the intact fruit. Aminoethoxyvinylglycine (AVG), an inhibitor of ethylene synthesis, and 2,5-norbornadiene (NBD) and Ag+, inhibitors of ethylene action, inhibit disc ripening, as does 2,4-dichlorophenoxyacetic acid (2,4-D), a synthetic auxin. On the other hand, none of the foregoing agents except Ag+, at concentrations that delay or prevent ripening, suppress the induction of four ripening-related genes encoding cellulase, polygalacturonase (PG), cytochrome P-450 oxidase (P-450), and ethylene-forming enzyme (EFE, or 1-aminopropane-1-carboxylic acid oxidase), respectively. Whereas Ag+ fully inhibits the production of cellulase and PG mRNAs, it has little effect on the induction of EFE and P-450 mRNAs. Cellulase and PG enzyme activities are absent in extracts of discs treated with AVG, NBD, or 2,4-D, as are antigenically detectable cellulase and PG proteins. The strong appearance of ripening-related mRNAs in discs inhibited from softening by ethylene antagonists suggests posttranscriptional control by ethylene. Similarly, inhibition of ripening by 2,4-D without suppression of mRNA induction suggests translational control. Whether ethylene inhibits transcription or postttranscriptional events or both depends on its concentration.
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PMID:Ethylene-Mediated Posttranscriptional Regulation in Ripening Avocado (Persea americana) Mesocarp Discs. 1223 32

The changes in cellular wall hydrolases, cellular wall components and cellular wall ultrastructure of postharvest persimmon (Diospyros kaki L. cv. Bianhua) fruit during softening were studied. Pectinesterase activity increased sharply at first and reached a peak (Fig.3A). Significant correlation was observed between the pectinesterase activity and the loss of flesh firmness (r= -0.74). Polygalacturonase activity increased slowly (Fig.3B), but there was no significant correlation between the polygalacturonase activity and the loss of flesh firmness. Beta-galactosidase activity increased sharply (Fig.3C), with a negative correlation between the b-galactosidase activity and the loss of flesh fruit firmness (r= -0.77). Cellulase activity increased markedly during ripening (Fig.3D). Significant correlation was observed between cellulase activity and the loss of flesh firmness (r= -0.90). Consistent with the increases in activity of cell wall hydrolases of cell wall constituents, fruit softening was accompanied by a progressive increase in WSP (water soluble pectin) content and a progressive decrease in protopectin and cellulose content (Fig.4). The cell wall structure was integrated when persimmon was harvested (Fig.5A). After 3 d of ripening, the middle lamella became liquefied (Fig.5B), or even the primary cell wall was dissolved in some regions (Fig.5C).
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PMID:[Changes in cell wall component metabolism and ultrastructure of postharvest persimmon fruit during softening]. 1636 94

Purified polygalacturonases from two fungi released proteins from wall fractions prepared from three plant species. Peroxidase activity was associated with the proteins released from the cell walls, and several of the protein fractions released contained hydroxyproline. Cellulase, purified free of pectic enzyme activity, was ineffective in releasing cell wall proteins. Specific inhibition of endopolygalacturonase activity prevented release of the proteins.
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PMID:Polygalacturonases Release Cell-Wall-bound Proteins. 1665 53

Cellulase, polygalacturonase (PG), pectinmethylesterase (PME), respiration, and ethylene production were determined in single "Fuerte" avocado fruits from the day of harvest through the start of fruit breakdown. PME declined from its maximum value at the time of picking to a low level early in the climacteric. PG activity was not detectable in the preclimacteric stage, increased during the climacteric, and continued to increase during the postclimacteric phase to a level three times greater than when the fruit reached the edible soft stage. Cellulase activity was low in the preclimacteric fruit, started to increase just as respiration increased, and reached a level two times greater than at the edible soft stage. Cellulase activity started to increase 3 days before PG activity could be detected. Increased production of ethylene followed the increase in respiration and cellulase activity by about 1.5 days. These results indicate that a close relation exists between the rapid increase in the cell wall-depolymerizing enzymes and the rise in respiration and ethylene production and refocused attention on the role of the cell wall and the associated plasma membrane in the early events of fruit ripening.
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PMID:Postharvest Variation in Cellulase, Polygalacturonase, and Pectinmethylesterase in Avocado (Persea americana Mill, cv. Fuerte) Fruits in Relation to Respiration and Ethylene Production. 1666 Sep 54


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