Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:3.2.1.23 (beta-galactosidase)
 14,648 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Coproduction of alpha-amylase, beta-amylase, amyloglucosidase, cellulase, xylanase, pectinase and beta-galactosidase by Sclerotium rolfsii was studied on various polysaccharides. Starch induced alpha-amylase, beta-amylase, amyloglucosidase and beta galactosidase; cellulose induced cellulase, xylanase, pectinase and beta-galactosidase; and pectin induced pectinase and beta-galactosidase. None of the enzymes studied except beta-galactosidase were induced on xylan. Group controlled mechanism for production of carbohydrases by Sclerotium rolfsii is suggested.
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PMID:Production of carbohydrases by Sclerotium rolfsii. 128 2

We have isolated and characterized cDNA clones of a gene family (P2) expressed in Oenothera organensis pollen. This family contains approximately six to eight family members and is expressed at high levels only in pollen. The predicted protein sequence from a near full-length cDNA clone shows that the protein products of these genes are at least 38,000 daltons. We identified the protein encoded by one of the cDNAs in this family by using antibodies to beta-galactosidase/pollen cDNA fusion proteins. Immunoblot analysis using these antibodies identifies a family of proteins of approximately 40 kilodaltons that is present in mature pollen, indicating that these mRNAs are not stored solely for translation after pollen germination. These proteins accumulate late in pollen development and are not detectable in other parts of the plant. Although not present in unpollinated or self-pollinated styles, the 40-kilodalton to 45-kilodalton antigens are detectable in extracts from cross-pollinated styles, suggesting that the proteins are present in pollen tubes growing through the style during pollination. The proteins are also present in pollen tubes growing in vitro. Both nucleotide and amino acid sequences are similar to the published sequences for cDNAs encoding the enzyme polygalacturonase, which suggests that the P2 gene family may function in depolymerizing pectin during pollen development, germination, and tube growth. Cross-hybridizing RNAs and immunoreactive proteins were detected in pollen from a wide variety of plant species, which indicates that the P2 family of polygalacturonase-like genes are conserved and may be expressed in the pollen from many angiosperms.
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PMID:Characterization of a gene family abundantly expressed in Oenothera organensis pollen that shows sequence similarity to polygalacturonase. 215 16

Activities of twelve hydrolytic enzymes in the digestive tract of young rabbits before weaning (4 weeks old) and adult rabbits (3 months old) were measured. The principal digestive enzymes in both groups of rabbits appeared to be amylase (EC 3.2.1.1), maltase (EC 3.2.1.20), pectinase (EC 3.2.1.15) and proteinases. The stomach of young rabbits contained most of the lipolytic activity and 45.7% of the total proteolytic activity of the digestive tract. The highest specific activities (per g digesta) of amylase, maltase and proteinase in young rabbits were found in the small intestine. Total activities (per segment) of amylase and maltase in the small intestine and the caecum were similar. Activities of cellulase (EC 3.2.1.4), inulinase (EC 3.2.1.7) and beta-glucosidase (EC 3.2.1.21) were low and activity of pectinase was fairly high in all segments of the digestive tract. The highest activity of urease (EC 3.5.1.5) was found in the caecum. Enzymic profiles of the colonic chymus resembled those of the caecum. Total hydrolytic activity was lower in the colon than in the caecum. Specific activities of amylase and invertase (EC 3.2.1.26) were lower and those of inulinase and lactase (EC 3.2.1.23) higher in 4-week-old rabbits than in 3-month-old rabbits. Gastric proteinase represented almost half of the total proteolytic activity of the digestive tract, whereas lipolytic activity of gastric contents was not found in measurable quantities in adult rabbits. The caecal contents of adult rabbits contained most of the total activity of lipase (EC 3.1.1.3), cellulase, xylanase (EC 3.2.1.32), pectinase, lactase, invertase, beta-glucosidase and urease present in the digestive tract.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Distribution of activity of hydrolytic enzymes in the digestive tract of rabbits. 753 89

Aspergillus niger cinnamoyl esterase (CinnAE) is shown to be active towards a wide range of feruloylated oligosaccharides derived from sugar-beet pulp (SBP). The esterase hydrolysed ferulic acid ester-linked to either C-2 of arabinose or C-6 of galactose residues, and demonstrated the highest activity towards the feruloylated arabinose trisaccharide. However, CinnAE was able to release only 0.88% of total alkali-extractable ferulic acid from SBP in 24 h when acting alone. To determine whether cell-wall-degrading enzymes could increase the release of ferulic acid by CinnAE, SBP was incubated with various carbohydrases [cellulase, polygalacturonase, endo-arabinanase, alpha-L-arabinofuranosidase, endo-(1,4-beta-D-galactanase, beta-D-galactosidase]. These were added alone and in pairs, both in the presence and absence of CinnAE. We showed that all the carbohydrases tested were free of esterase activity. When individual carbohydrases were incubated with SBP, whether in the presence or absence of CinnAE, less than 1% of the feruloyl groups were released. When incubated with a mixture of endo-arabinanase and alpha-L-arabinofuranosidase, the esterase was able to release 14 times more of the alkali-extractable ferulic acid present in the whole pulp as free acid than CinnAE alone. Ferulic acid is linked either to L-arabinose or D-galactose in SBP, but no corresponding increase in ferulic acid release was detected when SBP was incubated with CinnAE plus endo-(1,4)-beta-D-galactanase and beta-D-galactosidase (both from A. niger). Hence feruloylated arabinans in SBP are readily available for hydrolysis by arabinan-degrading enzymes, whereas feruloylated galactans are not available for hydrolysis by galactan-degrading enzymes.
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PMID:Release of ferulic acid from sugar-beet pulp by using arabinanase, arabinofuranosidase and an esterase from Aspergillus niger. 867 11

Pichia pinus was found to be capable of growing on mango wastes, producing pectinase (pectin lyase, EC-4.2.2.10) and lactase (beta-galactosidase, EC-3.2.1.23) enzymes. The two enzymes were successively purified by precipitation with ammonium sulfate followed by chromatography on Sephadex G-120. The purification procedure provided 1,846 and 929 fold purification with 20.6 and 24% yield recovery of pectinase and lactase, respectively. the km value of pectinase was 0.33% for pectin at pH 4.5 and that for lactase was 0.166% for lactose at pH 7.0. The purified enzymes, pectinase and lactase are stable up to 50 degrees C for 60 and 45 min, respectively, with 20 and 35% loss of their activity. Gel filtration on Sephadex G-200 indicated that the molecular weights of the purified pectinase was 90 x 10(3) Dalton and of lactase 115 x 10(3) Dalton. On the basis of the evaluation tests done, the enzymes were considered to have a potential technological interest as treating mango pastes (residues left after mango juice preparation) with the two prepared enzymes resulted in an increase of the colour intensity, total carbohydrate content and juice yield. Treating milk with the purified lactase also showed an increase in the total carbohydrate and reducing sugar produced.
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PMID:Evaluation of enzymes produced from yeast. 1070

Previous work in our laboratory has shown that Saccharomyces bayanus strain SCPP is the only reported yeast expressing the three types of pectolytic enzymes: pectin esterases, pectin lyases and polygalacturonases. One of these enzymes, the endopolygalacturonase (endoPG), hydrolyses plant-specific polysaccharide pectin. The endoPG encoding gene (PGU1) is also present in Saccharomyces cerevisiae. It has been shown that this endoPG is required for the development of pseudohyphae. Using genomic DNA, the PGU1-1 and PGU1-2 promoters of these strains have been amplified and used to construct gene fusions with the beta-galactosidase gene. On the basis of beta-galactosidase measurements, we compared the expression of both promoters in different environmental conditions in order to identify their modulation. We have shown that the PGU1 gene is upregulated by the presence of the pectin and the product resulting from endopolygalacturonase activity. Moreover, expression of the PGU1 is also enhanced under respiratory and filament formation conditions.
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PMID:Regulation of the expression of endopolygalacturonase gene PGU1 in Saccharomyces. 1125 50

Excessive softening is the main factor limiting fruit shelf life and storage. Transgenic plants modified in the expression of cell wall modifying proteins have been used to investigate the role of particular activities in fruit softening during ripening, and in the manufacture of processed fruit products. Transgenic experiments show that polygalacturonase (PG) activity is largely responsible for pectin depolymerization and solubilization, but that PG-mediated pectin depolymerization requires pectin to be de-methyl-esterified by pectin methylesterase (PME), and that the PG beta-subunit protein plays a role in limiting pectin solubilization. Suppression of PG activity only slightly reduces fruit softening (but extends fruit shelf life), suppression of PME activity does not affect firmness during normal ripening, and suppression of beta-subunit protein accumulation increases softening. All these pectin-modifying proteins affect the integrity of the middle lamella, which controls cell-to-cell adhesion and thus influences fruit texture. Diminished accumulation of either PG or PME activity considerably increases the viscosity of tomato juice or paste, which is correlated with reduced polyuronide depolymerization during processing. In contrast, suppression of beta-galactosidase activity early in ripening significantly reduces fruit softening, suggesting that the removal of pectic galactan side-chains is an important factor in the cell wall changes leading to ripening-related firmness loss. Suppression or overexpression of endo-(1-->4)beta-D-glucanase activity has no detectable effect on fruit softening or the depolymerization of matrix glycans, and neither the substrate nor the function for this enzyme has been determined. The role of xyloglucan endotransglycosylase activity in softening is also obscure, and the activity responsible for xyloglucan depolymerization during ripening, a major contributor to softening, has not yet been identified. However, ripening-related expansin protein abundance is directly correlated with fruit softening and has additional indirect effects on pectin depolymerization, showing that this protein is intimately involved in the softening process. Transgenic work has shown that the cell wall changes leading to fruit softening and textural changes are complex, and involve the coordinated and interdependent activities of a range of cell wall-modifying proteins. It is suggested that the cell wall changes caused early in ripening by the activities of some enzymes, notably beta-galactosidase and ripening-related expansin, may restrict or control the activities of other ripening-related enzymes necessary for the fruit softening process.
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PMID:Cell wall metabolism in fruit softening and quality and its manipulation in transgenic plants. 1155 79

During ripening of grape (Vitis vinifera L.) berries, softening occurs concomitantly with the second growth phase of the fruit and involves significant changes in the properties of cell wall polysaccharides. Here, the activities of enzymes that might participate in cell wall modification have been monitored throughout berry development. Alpha-galactosidase (EC 3.2.1.22), beta-galactosidase (EC 3.2.1.23) and pectin methylesterase (EC 3.1.1.11) activities were present, but no polygalacturonase (EC 3.2.1.15), cellulase (EC 3.2.1.4), xyloglucanase (xyloglucan-specific cellulase EC 3.2.1.4) or galactanase (EC 3.2.1.89) could be detected. The accumulation of mRNAs encoding wall-modifying enzymes was examined by northern hybridization analysis. Transcripts for beta-galactosidase, pectin methylesterase, polygalacturonase, pectate lyase (EC 4.2.2.2) and xyloglucan endotransglycosylase (EC 2.4.1.207) were present during ripening, although polygalacturonase activity had not been detected in berry extracts. Cellulases could not be detected in ripening berries, either at the enzyme or mRNA levels. The increase in beta-galactosidase activity and mRNA is consistent with the observed decrease in type-I arabinogalactan content of the walls during ripening, and the detection of polygalacturonase and pectate lyase mRNAs might explain the increased solubility of galacturonan in walls of ripening grapes. Thus, the modification of cell wall polysaccharides during softening of grape berries is a complex process involving subtle changes to different components of the wall, and in many cases only small amounts of enzyme activity are required to effect these changes.
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PMID:Expression patterns of cell wall-modifying enzymes during grape berry development. 1180 Mar 90

The activity of four cell wall hydrolases, pectinmethylesterase (PME), polygalacturonase (PG), cellulase, and beta-galactosidase (beta-Gal), was measured in fruit skins of two prickly pear varieties, Naranjona and Charola, during storage at 18 degrees C and 85-95% relative humidity (RH). In Naranjona (Opuntia ficus indica), of short postharvest life (ca. 2 weeks), PG, cellulase, and beta-Gal increased their activity more than twice, whereas PME activity tended to increase only slightly during storage. In Charola (Opuntia sp.), of long postharvest life (ca. 2 months), only beta-Gal increased its activity (77%), showing a high PG activity from the beginning of storage. Transmission electron microscopy observations showed middle lamella dissolution at the end of storage for both varieties. Naranjona showed a higher cell wall enzymatic activity than Charola, in agreement with their storability differences. Our results suggest that PG and cellulase in Naranjona and PG and beta-Gal in Charola are the main enzymes responsible for cell wall hydrolytic and ultrastructural changes in skins of stored prickly pears.
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PMID:Hydrolytic activity and ultrastructural changes in fruit skins from two prickly pear (Opuntia sp.) varieties during storage. 1187 58

Glycosyl-hydrolytic enzymes from suspension-cultured carrot (Daucus carota L. cv. Kintoki) cells grown in calcium (Ca2+)-deficient and normal liquid media were studied after extraction successively by K-phosphate (pH 7.0) and Na-acetate (pH 5.2) containing 3 M LiCl. The same activities were detected in two protein fractions from control and Ca2+-deprived cells. The specific activities of alpha-galactosidase and polygalacturonase decreased under Ca2+ deprivation, but beta-galactosidase activity in the buffer-soluble protein from Ca2+-deprived cells increased 1.7-fold compared to control cells. Upon ion exchange and size-exclusion chromatography the fraction (Ca-Ia-I) in the buffer-soluble protein from Ca2+-deprived cells represented beta-galactosidase activity associated with a galacturonic acid-rich polysaccharide peak, whereas the corresponding fraction could hardly be detected in the buffer-soluble protein from control cells. Several of the same glycosidase activities were detected in the extract solubilized with cyclohexane-trans-1,2-diaminetetra-acetate (CDTA) from active cell walls of Ca2+-deprived cells as in the extract of control cells, but the beta-galactosidase activity was considerably reduced under Ca2+ deprivation. Following the same chromatography the fraction (CDTA-Ca-1) of beta-galactosidase activity in the extract solubilized with CDTA from active cell walls of Ca2+-deprived cells was also completely overlapping with the peak of galacturonic acid-rich polysaccharide. The molecular mass of fractions Ca-Ia-I and CDTA-Ca-1 was 300 kDa, and the polysaccharides in these two fractions were composed of approximately equal amounts of rhamnosyl and galacturonosyl residues. These results suggest that the increase of beta-galactosidase in the buffer-soluble protein fraction from Ca2+-deprived cells is the result of solubilization of a part of the acidic pectic polymer-bound beta-galactosidase due to the structural changes in the cell walls that occur during Ca2+ deprivation.
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PMID:Pectin-bound beta-galactosidase present in cell walls of carrot cells under the different calcium status. 1190 68


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