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)

Endo-pectin lyase and endo-polygalacturonase of Aspergillus japonicus attack the middle lamella of plant tissue and cause tissue maceration. Galacturonides, neutral sugars, and proteins were released from potato tuber tissues during maceration by both purified enzymes. These three components accounted for 92% of the soluble products. The neutral sugars released were rhamnose, arabinose, and galactose with a molar ratio of 1:3:15. They were covalently linked to galacturonides. Over 85% of the galacturonides released by the enzymes were short chain products, which indicated that a large portion of the main chain of pectic substances is a homogalacturonan. The results of chromatography on columns of Sephadex G-100 and DEAE-cellulose suggested that a protein component may be attached to pectic substances. This protein did not contain hydroxyproline and, therefore, was different from the cell wall structural glycoprotein.
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PMID:Analysis of the Components Released from Potato Tuber Tissues during Maceration by Pectolytic Enzymes. 1666 May 64

Changes in neutral sugar, uronic acid, and protein content of tomato (Lycopersicon esculentum Mill) cell walls during ripening were characterized. The only components to decline in amount were galactose, arabinose, and galacturonic acid. Isolated cell walls of ripening fruit contained a water-soluble polyuronide, possibly a product of in vivo polygalacturonase action. This polyuronide and the one obtained by incubating walls from mature green fruit with tomato polygalacturonase contained relatively much less neutral sugar than did intact cell walls. The ripening-related decline in galactose and arabinose content appeared to be separate from polyuronide solubilization. In the rin mutant, the postharvest loss of these neutral sugars occurred in the absence of polygalacturonase and polyuronide solubilization. The enzyme(s) responsible for the removal of galactose and arabinose was not identified; a tomato cell wall polysaccharide containing galactose and arabinose (6:1) was not hydrolyzed by tomato beta-galactosidase.
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PMID:Degradation of Cell Wall Polysaccharides during Tomato Fruit Ripening. 1666 Jun 60

An elicitor of phytoalexin accumulation (endogenous elicitor) is solubilized from purified cell walls of soybean (Glycine max [L.] Merr., cv. Wayne) by extracting the walls with hot water or by subjecting the walls to partial acid hydrolysis. The endogenous elicitor obtained from soybean cell walls binds to an anion exchange resin. The elicitor-active material released from the resin contains oligosaccharides rich in galacturonic acid; small amounts of rhamnose and xylose are also present. The preponderance of galacturonic acid in the elicitor-active fragments suggests that the elicitor is, in fact, a fragment of a pectic polysaccharide. This possibility is supported by the observation that treatment of the wall fragments with a highly purified endopolygalacturonase destroys their ability to elicit phytoalexin accumulation. This observation, together with other evidence presented in this paper, suggests that galacturonic acid is an essential constituent of the elicitor-active wall fragments. Endogenous elicitors were also solubilized by partial hydrolysis from cell walls of suspension-cultured tobacco, sycamore, and wheat cells.
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PMID:Host-Pathogen Interactions : XIX. THE ENDOGENOUS ELICITOR, A FRAGMENT OF A PLANT CELL WALL POLYSACCHARIDE THAT ELICITS PHYTOALEXIN ACCUMULATION IN SOYBEANS. 1666 68

Fractionation of pectic polysaccharides from the juice of ripening ;Bartlett' pears (Pyrus communis) gave two general types of polyuronides. The major type was a homogalacturonan (HGA) whose molecular weight decreased upon ripening. The other type comprised heteropolymers composed of various amounts of arabinose, rhamnose, and galactose. Treatment of the major arabinose-containing heteropolymeric fraction of high molecular weight (400,000) with a pear exo-polygalacturonase to degrade contaminating HGA gave a polyuronide which was inert to tomato endopolygalacturonase. Glycosyl-linkage analysis of this arabinosyl-polyuronide gave results expected from a rhamnogalacturonan I-like polysaccharide with large, highly branched araban side chains (RG-I). A linkage between HGA and RG-I was not found. RG-I, in ripening pears, appeared to be degraded with the initial loss of much of its arabinose.
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PMID:Cell Wall Metabolism in Ripening Fruit: IV. Characterization of the Pectic Polysaccharides Solubilized during Softening of ;Bartlett' Pear Fruit. 1666 15

Cell wall isolation procedures were evaluated to determine their effect on the total pectin content and the degree of methylesterification of tomato (Lycopersicon esculentum L.) fruit cell walls. Water homogenates liberate substantial amounts of buffer soluble uronic acid, 5.2 milligrams uronic acid/100 milligrams wall. Solubilization appears to be a consequence of autohydrolysis mediated by polygalacturonase II, isoenzymes A and B, since the uronic acid release from the wall residue can be suppressed by homogenization in the presence of 50% ethanol followed by heating. The extent of methylesterification in heat-inactivated cell walls, 94 mole%, was significantly greater than with water homogenates, 56 mole%. The results suggest that autohydrolysis, mediated by cell wall-associated enzymes, accounts for the solubilization of tomato fruit pectin in vitro. Endogenous enzymes also account for a decrease in the methylesterification during the cell wall preparation. The heat-inactivated cell wall preparation was superior to the other methods studied since it reduces beta-elimination during heating and inactivates constitutive enzymes that may modify pectin structure. This heat-inactivated cell wall preparation was used in subsequent enzymatic analysis of the pectin structure. Purified tomato fruit polygalacturonase and partially purified pectinmethylesterase were used to assess changes in constitutive substrates during tomato fruit ripening. Polygalacturonase treatment of heat-inactivated cell walls from mature green and breaker stages released 14% of the uronic acid. The extent of the release of polyuronides by polygalacturonase was fruit development stage dependent. At the turning stage, 21% of the pectin fraction was released, a value which increased to a maximum of 28% of the uronides at the red ripe stage. Pretreatment of the walls with purified tomato pectinesterase rendered walls from all ripening stages equally susceptible to polygalacturonase. Quantitatively, the release of uronides by polygalacturonase from all pectinesterase treated cell walls was equivalent to polygalacturonase treatment of walls at the ripe stage. Uronide polymers released by polygalacturonase contain galacturonic acid, rhamnose, galactose, arabinose, xylose, and glucose. As a function of development, an increase in the release of galacturonic acid and rhamnose was observed (40 and 6% of these polymers at the mature green stage to 54 and 15% at the red ripe stage, respectively). The amount of galactose and arabinose released by exogenous polygalacturonase decreased during development (41 and 11% from walls of mature green fruit to 11 and 6% at the red ripe stage, respectively). Minor amounts of glucose and xylose released from the wall by exogenous polygalacturonase (4-7%) remained constant throughout fruit development.
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PMID:Tomato fruit cell wall : I. Use of purified tomato polygalacturonase and pectinmethylesterase to identify developmental changes in pectins. 1666 42

Physiological processes characteristic of ripening in tissues of intact tomato fruit (Lycopersicon esculentum Mill.) were examined in excised pericarp discs. Pericarp discs were prepared from mature-green tomato fruit and stored in 24-well culture plates, in which individual discs could be monitored for color change, ethylene biosynthesis, and respiration, and selected for cell wall analysis. Within the context of these preparation and handling procedures, most whole fruit ripening processes were maintained in pericarp discs. Pericarp discs and matched intact fruit passed through the same skin color stages at similar rates, as expressed in the L(*)a(*)b(*) color space, changing from green (a(*) < -5) to red (a(*) > 15) in about 6 days. Individual tissues of the pericarp discs changed color in the same sequence seen in intact fruit (exocarp, endocarp, then vascular parenchyma). Discs from different areas changed in the same spatial sequence seen in intact fruit (bottom, middle, top). Pericarp discs exhibited climacteric increases in ethylene biosynthesis and CO(2) production comparable with those seen in intact fruit, but these were more tightly linked to rate of color change, reaching a peak around a(*) = 5. Tomato pericarp discs decreased in firmness as color changed. Cell wall carbohydrate composition changed with color as in intact fruit: the quantity of water-soluble pectin eluted from the starch-free alcohol insoluble substances steadily increased and more tightly bound, water-insoluble, pectin decreased in inverse relationship. The cell wall content of the neutral sugars arabinose, rhamnose, and galactose steadily decreased as color changed. The extractable activity of specific cell wall hydrolases changed as in intact fruit: polygalacturonase activity, not detectable in green discs (a(*) = -5), appeared as discs turned yellow-red (a(*) = 5), and increased another eight-fold as discs became full red (a(*) value +20). Carboxymethyl-cellulase activity, low in extracts from green discs, increased about six-fold as discs changed from yellow (a(*) = 0) to red.
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PMID:Comparison of ripening processes in intact tomato fruit and excised pericarp discs. 1666 93

The ability of a commercial Trichoderma reesei cellulase preparation (Celluclast 1.5L), to hydrolyze the cellulose and xylan components of pretreated corn stover (PCS) was significantly improved by supplementation with three types of crude commercial enzyme preparations nominally enriched in xylanase, pectinase, and beta-glucosidase activity. Although the well-documented relief of product inhibition by beta-glucosidase contributed to the observed improvement in cellulase performance, significant benefits could also be attributed to enzymes components that hydrolyze non-cellulosic polysaccharides. It is suggested that so-called "accessory" enzymes such as xylanase and pectinase stimulate cellulose hydrolysis by removing non-cellulosic polysaccharides that coat cellulose fibers. A high-throughput microassay, in combination with response surface methodology, enabled production of an optimally supplemented enzyme mixture. This mixture allowed for a approximately twofold reduction in the total protein required to reach glucan to glucose and xylan to xylose hydrolysis targets (99% and 88% conversion, respectively), thereby validating this approach towards enzyme improvement and process cost reduction for lignocellulose hydrolysis.
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PMID:Optimization of enzyme complexes for lignocellulose hydrolysis. 1705 83

UV-C irradiation (254 nm) was found to enhance the secretion of some cell-wall-degrading enzymes, especially the following carbohydrases: beta-galactosidase, alpha-L-arabinofuranosidase, polygalacturonase, pectinesterase, cellulase, xylanase, and beta-xylosidase, in the campion callus, contributing thereby to an alteration in the polysaccharide structure. The relative amounts of the galactose and arabinose residues in pectin (silenan) and of arabinose in arabinogalactan of calli irradiated during the exponential phase were shown to decrease during the stationary phase. A decrease in the degree of SV methylesterification was found for the irradiated callus. These alterations were found to persist over a long period of culturing time. Decreasing the relative amounts of the arabinose residues in arabinogalactan and pectin and the galactose residues in silenan corresponded to increasing activity of alpha-L-arabinofuranosidase and beta-galactosidase, respectively, due to treatment with UV-C. UV-C irradiation may be used as a tool for modifying the structural features of the cell-wall polysaccharides, such as the relative amounts of galactose and arabinose residues in the side chains of polysaccharides, with the purpose of obtaining physiologically active polysaccharides with the desired properties and structural features.
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PMID:Influence of ultraviolet-C on the compositions of cell-wall polysaccharides and carbohydrase activities of Silene vulgaris callus. 1718 64

A pectin polysaccharide named bergenan was isolated from the freshly collected leaves of the leather bergenia Bergenia crassifolia by extraction with an aqueous solution of ammonium oxalate. The main component of its carbohydrate chain was shown to be the residues of D-galacturonic acid (about 80%). In addition, the polysaccharide contains residues of galactose, arabinose, and rhamnose; their total content is less than 15%. It was shown that the bergenan samples from bergenia leaves collected at different vegetation periods (from July to September) do not substantially differ either in monosaccharide composition or in the viscosity of aqueous solutions they form. The results of enzymatic hydrolysis by alpha-1,4-galacturonase (pectinase), partial acidic hydrolysis, NMR spectroscopy, and methylation with subsequent analysis of the results by GC-MS indicate that the bergenan macromolecule contains the regions of a linear alpha--1,4-D-galactopyranosyluronan and rhamnogalacturonan-I (RG-1). Galacturonan responds for a greater part of the macromolecule. A considerable amount of its constituent galacturonic acid residues are present as methyl esters. The side chains in RG-I are attached to the rhamnopyranose residues of the main carbohydrate chain by 1,4-link and are composed of the residues of terminal arabinofuranose and galactopyranose, 1,5-linked (-arabinofuranose, and 1,4-and 1,6-linked beta-galactopyranose. The branching points of the side chains of the RG-I molecule are 3,4- and 3,6-di-O-substituted galactose residues.
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PMID:[Structural study of bergenan, a pectin from Bergenia crassifolia]. 1737 59

Polysaccharides (pectin and intracellular and extracellular arabinogalactans) were isolated from campion callus culture cultivated on medium with varied concentrations of pectinase and beta-galactosidase. A decrease in contents of arabinose residues in pectin and arabinogalactans and of galactose residues in arabinogalactans was associated with an increase in the activities of alpha-L-arabinofuranosidase and beta-galactosidase upon addition of pectinase into the medium. Pectinase destroyed the high-molecular-weight (more than 300 kD) fraction of pectin and decreased the content of galacturonic acid residues. alpha-L-Arabinofuranosidase transformed arabinogalactan into galactan, and galactan was destroyed under the influence of galactosidase. The contents of arabinogalactan and/or galactan in the cells were decreased, and it was released into the culture medium. Pectin samples with low contents of arabinose and galactose in the side chains and galactan samples were obtained from the callus grown on the medium with beta-galactosidase. Cultivation of the plant cells on medium containing carbohydrases resulted in modification of pectin and arabinogalactan of the cell walls.
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PMID:Modification of polysaccharides from callus culture of Silene vulgaris (M.) G. using carbohydrases in vitro. 1792 61


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