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:3.2.1.26 (invertase)
4,927 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Invertase, extracted from broken cells of Saccharomyces cerevisiae X-2180 mm2 mannan mutant, was separated into a fraction insoluble in 75% ammonium sulfate (P75 invertase, 36% carbohydrate) and a soluble fraction (S75 invertase, 53% carbohydrate). The latter reacted with antibodies specific for the alpha 1 leads to 6-linked mannose of the mannoprotein outer chain, whereas the P75 invertase failed to react with this antiserum although it did react with serum against terminal alpha 1 leads to 3-linked mannose units that are characteristic of the mannoprotein core. A bacterial endo alpha 1 leads to 6-mannanase removed the outer chains from the S75 invertase and converted it to a form that was similar in electrophoretic and immunochemical properties to the P75 invertase, whereas the endomannanase had little effect on the latter invertase. The results suggest that the P75 invertase is a form of the enzyme to which only the core oligosaccharide units had been added, and the S75 invertase represents an enzyme fraction to which the polysaccharide outer chains were also attached. A strong anomeric PMR signal for unsubstituted alpha 1 leads to 6-linked mannose in the S75 invertase, and a much reduced signal in the P75 invertase and endomannanase-digested S75 invertase, support these conclusions. Endo-N-acetyl-beta-glucosaminidase digestion of the S75 and P75 invertases, as well as of a purified wild type yeast invertase, produced an apparently identical series of 3 to 4 carbohydrate-containing proteins that were separable by polyacrylamide gel electrophoresis in sodium dodecyl sulfate but that migrated as a single band on isoelectric focusing. The bands ranged from about 63,000 to 69,000 daltons and differed by the size of one or more carbohydrate core units each of 15 mannoses and 1 N-acetylglucosamine. The results suggest that the external invertase molecules contain some core units without attached outer chains, and that the cells contain a precursor form of the enzyme to which only the core units have been added. In support of this conclusion, PMR spectra and chromatographic patterns show that the core fragments from the P75, S75, and wild type invertases are essentially identical.
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PMID:Carbohydrate structure of yeast invertase. Demonstration of a form with only core oligosaccharides and a form with completed polysaccharide chains. 11 81

Yeast external invertase (EC 3.2.1.25), a glycoenzyme consisting of equal parts by weight of protein and mannan, has been found to contain covalently bound phosphate. Three preparations (from two yeast strains) had mannose/PO4 ratios of 31-35, equivalent to 24-27 PO4 residues per mol of enzyme, while a fourth had only 7 PO4 residues per mol. From one of the high-PO4 enzymes, approx. 69% of the phosphorus was recovered as mannose 6-phosphate. No correlation was found between invertase activity and phosphorus content. The PO4 contents of the invertases exceeded those of the cell wall mannans from the respective yeasts. Thus, contamination of the invertases by cell wall phosphomannan is unlikely. Electrofocusing of the low-PO4 invertase yielded four components with pI values from 3.96 to 4.40, and yeast internal invertase (a mannan- and PO4-free, cytoplasmic isozyme) was isoelectric at approx. pH 4.5. The high-PO4 invertase was considerably more heterogeneous, with two major species of pI 3.65 and 3.32 and a highly acidic component of pI smaller than 2.7; however, the mannose/PO4 ratio of each species was approximately the same. PO4-gradient elution from hydroxyapatite resolved the high-PO4 invertase into five isozymes of increasing acidity and mannan content. Since the mannose/PO4 ratios of these invertase species are constant, the increase in the mannan/protein (and, therefore PO4/protein ratio is apparently responsible for the microheterogeneity of phosphoinvertase.23
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PMID:Microheterogeneity in yeast invertase. 109 60

Saccharomyces cerevisiae invertase (EC 3.2.1.26) isolated from wild-type strain X2180 can be resolved by isoelectric focusing into at least seven bands revealed by an activity stain. Most of this polymorphism is eliminated in mutants that are defective in phosphorylation of the mannoprotein carbohydrate chains (mnn4 and mnn6). In contrast to strain X2180, invertase from the mnn9 mutant, which makes mannoprotein lacking the outer portion of the polymannose chains, shows only two major bands on isoelectric focusing. Although mnn2 mannoprotein is though not to have any branches in its outer chain, the invertase of this mutant shows at least six bands on isoelectric focusing, and digestion of this invertase with an endo-alph aI leads to 6-mannanase that removes the unbranched outer chain produces an invertase with two bands that are similar to those from the mnn9 mutant. The invertase from mnn2 cells, grown with [32P]orthophosphate and precipitated with specific antiserum, gives at least five radioactive bands on isoelectric focusing, and after digestion with the endomannanase the radioactivity no longer migrates with the residual invertase. Mutants with shortened and unbranched outer chains (mnn2 mnn7, mnn2 mnn8, and mnn2 mnn10) give invertase patterns similar to mnn2. The results suggest that multiple states of outer chain phosphorylation lead to isoelectric polymorphism of S. cerevisiae external invertase and, because invertase has nine carbohydrate chains, no more than one phosphate group per chain would be required to account for this property.
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PMID:Yeast invertase polymorphism is correlated with variable states of oligosaccharide chain phosphorylation. 675 65

Glycosidases and glycosyltransferases were electrophoresed in the presence of sodium dodecyl sulfate (SDS) in a thin-layer gel supported by a glass plate, treated with the nonionic detergent Triton X-100, and specifically stained for the sugar-releasing activity of these enzymes. Staining is based on conversion of monosugars or a sugar phosphate to glucose-6-phosphate by the appropriate intermediary enzymes, reduction of NADP+ to NADPH, and accumulation of reduced Nitroblue Tetrazolium in the gel. Among the enzymes tested, alpha-glucosidase, beta-glucosidase and beta-mannosidase could not be renatured, whereas beta-fructofuranosidase and alpha-mannosidase could be renatured unless heated before electrophoresis. Sucrose phosphorylase, glucosyltransferase and fructosyltransferase, which are single-peptide proteins with no cystine bond, could be renatured even after pretreatment with SDS and/or mercaptoethanol at 100 degrees C for 10 min. However, exclusive heating remarkably decreased the activities of these enzymes. Two-dimensional separation of the five renaturable enzymes was done in a single thin-layer gel, using SDS-electrophoresis in the first dimension and isoelectric focusing in the second dimension.
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PMID:Renaturation and activity staining of glycosidases and glycosyltransferases in gels after sodium dodecyl sulfate-electrophoresis. 752 70

Chromatographic separation of the pod extract of Angylocalyx pynaertii resulted in the isolation of 13 sugar-mimic alkaloids (1-13). The structures of the new alkaloids were elucidated by spectroscopic methods as the 6-O-beta-D-glucoside (10) and N-hydroxyethyl derivative (11) of 1,4-dideoxy-1,4-imino-D-arabinitol (DAB) (1), 1,6-dideoxynojirimycin (12), and 1,3,4-trideoxynojirimycin (13). 2,5-Imino-1,2,5-trideoxy-L-glucitol (7), 2,5-dideoxy-2,5-imino-D-fucitol (8), and beta-homofuconojirimycin (9), isolated from the pods as well as the bark, were very specific inhibitors of alpha-L-fucosidase with no significant inhibitory activity toward other glycosidases. In this work, 1,4-dideoxy-1,4-imino-D-ribitol (6) was found to be a better inhibitor of lysosomal beta-mannosidase than 2,5-imino-1,2,5-trideoxy-D-mannitol (2). N-Hydroxyethyl-1-deoxynojirimycin (miglitol), which is commercially available for the treatment of diabetes, retained its inhibitory potential toward rat intestinal maltase and sucrase, whereas 11 and the synthetic N-hydroxyethyl derivative of 2,5-dideoxy-2,5-imino-D-mannitol markedly lowered or abolished their inhibition toward all enzymes tested.
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PMID:New sugar-mimic alkaloids from the pods of Angylocalyx pynaertii. 1185 56

The different growth responses under control and moderate salinity (70 mM NaCl) in relation to the carbon partitioning and sucrose metabolism in developing tomato fruits [20 days after anthesis (DAA), start of ripening and ripe stages] were studied in the cultivated tomato Lycopersicon esculentum Mill (cv. H-324-1), in the wild relative species L. cheesmanii (ac. LA-530) (hexose-accumulators), L. chmielewskii (ac. LA-1028) (sucrose-accumulator) and in two interspecific F1 hybrids (hexose-accumulators) (F1-530: H-324-1 x A-530, F1-1028: H-324-1 x A-1028). The higher salt-tolerance of the wild species and hybrids with respect to the domestic tomatoes was also observed at the fruit level because these genotypes were less affected in the assimilation of dry weight (DW) under salinity. With the exception of the wild tomatoes, the sink strength, evaluated as the dry matter accumulation rate (mg DW day-1) and the sink activity, evaluated as a relative growth rate (mg DW mg-1 day-1), were reduced during the early fruit growing period (20 DAA-start ripening). However, a total recovery of growth was registered in the salinized hybrid fruits during the late growing period (start of ripening-ripe fruits). The early reduction in sink activity in the hybrid and domestic fruits was related to a sucrose accumulation and a decrease in the total sucrolytic activity at 20 DAA, especially the cytoplasmic sucrolytic activities sucrose synthase (EC 2.4.1.13) and neutral invertase (EC 3.2.1.26). The further recovery in sink strength of the hybrid fruits was related to the maintenance of the insoluble acid invertase (EC 3.2.1.25) and the induction of the cytoplasmic sucrolytic activities, namely at the start of ripening stage, demonstrating the existence of an inverse relationship between these activities, which suggests a regulatory mechanism in order to maintain the sink capacity. The roles of different enzymes in the control of assimilate import under salinity in relation to the sucrose transport and possible regulatory mechanisms are discussed.
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PMID:Sucrolytic activities during fruit development of Lycopersicon genotypes differing in tolerance to salinity. 1270 12

Larval and adult Psacothea hilaris feed on mulberry wood and leaves, respectively. High levels of endogenous activity against the major dietary carbohydrates, cellulose, hemicellulose, starch and soluble sugars were secreted in the gut of larvae and adults. Activity against pectin was also high and multiple polygalacturonase (EC 3.2.1.15) components were secreted in the gut of larvae. One glycanase component, beta-EG1, which was primarily an endo-beta-1,4-glucanase (EC 3.2.1.4) and another, beta-EG2, which was mostly an endo-beta-1,4-xylanase (EC 3.2.1.8), were also secreted, while at least four additional components hydrolysed laminarin, lichenin and crystalline cellulose. The beta-glycosidase component beta-GD1 was associated with most of the beta-mannosidase (EC 3.2.1.25) and beta-xylosidase (EC 3.2.1.37) activity secreted in the gut of larvae, while another, beta-GD2, was a beta-glucosidase (EC 3.2.1.21), the activity of which was directed against cellobiose and other beta-linked disaccharides, and a beta-fucosidase (EC 3.2.1.38). A beta-galactosidase (EC 3.2.1.23), which did not hydrolyse lactose, was also secreted, as were distinct beta-N-acetylhexosaminidase (EC 3.2.1.52), trehalase (EC 3.2.1.28), alpha-L-arabinosidase (EC 3.2.1.55), alpha-galactosidase (EC 3.2.1.22) and a minimum of four alpha-glucosidase (EC 3.2.1.20) components, one of which was also likely to be associated with a peak of alpha-mannosidase (EC 3.2.1.24) activity. The alpha-glucosidase components varied in their specificity for alpha-linked disaccharides, but none was active against sucrose, which was hydrolysed by a beta-fructofuranosidase (EC 3.2.1.26) component. Overall average levels of activity in larvae were twice those of adults, but the secretion of individual carbohydrases in both was not regulated in response to the relative abundance of particular carbohydrate components in their respective diets.
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PMID:Diet and carbohydrate digestion in the yellow-spotted longicorn beetle Psacothea hilaris. 1277 Apr 76

Two experiments with young pigs (25 d of age) were conducted to investigate the effect of multienzyme preparations on nutrient digestibility, growth performance, and P utilization and excretion. In Exp. 1, 24 pigs (six pigs per treatment) were used in a 28-d performance and digestibility trial using four diets: control (no enzyme) and control supplemented with enzyme preparation A, B, or C. The control diet was formulated to meet 95% of NRC (1998) nutrient specifications (except for available P, which was at 44% NRC) and composed of corn, wheat, wheat by-products, barley, soybean meal, canola meal, and peas. All three enzyme preparations contained xylanase, glucanase, amylase, protease, invertase, and phytase activities and differed in the type of plant cell wall-degrading activities; Enzyme A contained cellulase, galactanase, and mannanase; Enzyme B contained cellulase and pectinase; and Enzyme C contained cellulase, galactanase, mannanase, and pectinase. Pigs fed enzyme-supplemented diets had higher ADG (P = 0.02) and G:F (P = 0.01) than those fed the control diet. On average, and when compared with control diet, enzyme supplementation improved (P = 0.001 to 0.04) ileal digestibility of DM (60 vs. 66%), GE (62.8 vs. 70.4%), CP (62 vs. 72%), starch (86.7 vs. 94.2%), nonstarch polysaccharides (NSP; 10.1 vs. 17.6%), and phytate (59 vs. 70%). Compared with the control, total-tract digestibility of nutrients was increased (P = 0.001 to 0.01) owing to enzyme supplementation, with Enzyme C showing the highest improvement in DM, GE, CP, starch, NSP, phytate, and P utilization. Pigs fed enzyme-supplemented diets had decreased (P = 0.04) fecal P excretion. The benefit from improved nutrient utilization with enzyme supplementation was further substantiated in a 38-d growth performance study with 48 pigs. The control and Enzyme C-supplemented diets (same as Exp. 1) were assigned to six replicate pens (four pigs per pen). The study was conducted in three phases (Phase 1 = d 0 to 7; Phase 2 = d 7 to 21; Phase 3 = d 21 to 38). Individual BW and pen feed disappearance were monitored. Average daily gain and G:F were 231 and 257 g (P = 0.01), and 0.56 and 0.63 (P = 0.001) for the control and enzyme-supplemented diets, respectively. It is evident from this study that the use of enzyme preparations may allow for cost-effective and environmentally friendly formulation of young pig diets.
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PMID:Dietary supplementation with multienzyme preparations improves nutrient utilization and growth performance in weaned pigs. 1508 Mar 27

A salt-sensitive genotype of Solanum lycopersicum cv. Volgogradskij was submitted to a 6-day treatment with high salt (100, 200 mM NaCl), allowed to recover for 6 days and then submitted to a second period of salt stress in order to study changes in carbohydrate metabolism related to salt adaptation. The ion, soluble sugar and starch contents, as well as sucrose biosynthetic and sugar mobilizing enzyme activities and transcript levels were determined during the salt stress/recovery/stress cycle. Sodium ions were found to accumulate preferentially in old leaves. Young leaves accumulated lower levels of sodium ions but maintained control levels of potassium ions. Hexoses accumulated to higher levels and starch was better maintained in young compared to old leaves during the two salt treatments. Sucrose accumulated dramatically only in old leaves during the initial salt treatment. Sugar accumulation was not related to decreases in the activities of sugar mobilizing enzymes, acid (EC 3.2.1.25) and neutral (EC 3.2.1.26) invertases, sucrose synthase (EC 2.4.1.13) and hexokinase (EC 2.7.1.1). The activity of the biosynthetic enzyme sucrose phosphate synthase (EC 2.3.1.14) was linked to changes in sucrose levels but not with transcript levels. These results point to the importance of post-transcriptional regulation. Transcriptional regulation could nevertheless be seen in the down-regulation of ribulose bisphosphate carboxylase small subunit (EC 4.1.1.39) in old compared to young leaves, but this was not related to sugar levels.
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PMID:Adaptive response to salt involving carbohydrate metabolism in leaves of a salt-sensitive tomato cultivar. 1762 95

The effect of low temperature on growth, sucrose-starch partitioning and related enzymes in salt-stressed and salt-acclimated cotyledons of quinoa (Chenopodium quinoa Willd.) was studied. The growth of cotyledons and growing axes in seedlings grown at 25/20 degrees C (light/dark) and shifted to 5/5 degrees C was lower than in those only growing at 25/20 degrees C (unstressed). However, there were no significant differences between low-temperature control and salt-treated seedlings. The higher activities of sucrose phosphate synthase (SPS, EC 2.4.1.14) and soluble acid invertase (acid INV, EC 3.2.1.25) were observed in salt-stressed cotyledons; however, the highest acid INV activity was observed in unstressed cotyledons. ADP-glucose pyrophosphorylase (ADP-GPPase, EC 2.7.7.27) was higher in unstressed cotyledons than in stressed ones. However, between 0 and 4days the highest value was observed in salt-stressed cotyledons. The lowest value of ADP-GPPase was observed in salt-acclimated cotyledons. Low temperature also affected sucrose synthase (SuSy, EC 2.4.1.13) activity in salt-treated cotyledons. Sucrose and glucose were higher in salt-stressed cotyledons, but fructose was essentially higher in low-temperature control. Starch was higher in low-temperature control; however, the highest content was observed at 0day in salt-acclimated cotyledons. Results demonstrated that low temperature induces different responses on sucrose-starch partitioning in salt-stressed and salt-acclimated cotyledons. Data also suggest that in salt-treated cotyledons source-sink relations (SSR) are changed in order to supply soluble sugars and proline for the osmotic adjustment. Relationships between starch formation and SuSy activity are also discussed.
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PMID:Low-temperature effect on enzyme activities involved in sucrose-starch partitioning in salt-stressed and salt-acclimated cotyledons of quinoa (Chenopodium quinoa Willd.) seedlings. 1912 55


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