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)

Two mutants carrying different deletions of the IMP2 coding sequence of Saccharomyces cerevisiae, delta T1, which encodes a protein lacking the last 26 C-terminal amino acids, and delta T2, which completely lacks the coding region, were analysed for derepression of glucose-repressible maltose, galactose, raffinose and ethanol utilization pathways in response to glucose limitation. The role of the IMP2 gene product in the regulation of carbon catabolite repressible enzymes maltase, invertase, alcohol dehydrogenase, NAD-dependent glutamate dehydrogenase (NAD-GDH) and L-lactate:ferricytochrome-c oxidoreductase (L-LCR) was also analysed. The IMP2 gene product is required for the rapid glucose derepression of all above-mentioned carbon source utilization pathways and of all the enzymes except for L-LCR. NAD-GDH is regulated by IMP2 in the opposite way and, in fact, this enzyme was released at higher levels in both imp2 mutants than in the wild-type strain. Therefore, the product of IMP2 appears to be involved in positive and negative regulation. Both deletions result in growth and catalytic defects; in some cases partial modification of the gene product yielded more dramatic effects than its complete absence. Moreover, evidence is provided that the IMP2 gene product regulates galactose- and maltose-inducible genes at the transcriptional level and is a positive regulator of maltase, maltose permease and galactose permease gene expression.
Microbiology (Reading) 1995 Sep
PMID:IMP2, a gene involved in the expression of glucose-repressible genes in Saccharomyces cerevisiae. 749 32

An experiment was conducted to determine the effect of two early nutrient restriction programs on performance, selected characteristics of the gastrointestinal tract (GIT), and activities of digestive enzymes of broiler chickens. Three hundred and sixty male broiler (Ross x Ross) chicks kept in floor pens were assigned to three groups. The control group (C) was given ad libitum access to feed from 1 to 48 d of age. Another group was restricted from 11 to 14 d (R4) of age to an energy intake of .74 x BW.67 kcal ME/d, and a third group was restricted from 7 to 14 d (R7) of age to an energy intake of 1.5 x BW.67 kcal ME/d. Then, both restricted groups were given ad libitum access to feed through 48 d. Body weight and feed intake were determined weekly and selected carcass characteristics were measured at 48 d of age. Broilers also were sampled at 7, 14, 21, and 42 d of age to obtain data on components of the GIT (proventriculus, gizzard, pancreas, and small intestine) and activities of selected digestive enzymes. Feed-restricted groups were lighter in body weight (P < .01) at 14 and 48 d of age than the C group but were superior in overall feed efficiency. No treatment effects were observed for percentage yields of breast meat and abdominal fat pad. Absolute weights of GIT components were significantly reduced at 14 d of age by feed restriction. However, GIT components increased in weight more quickly after refeeding than did the whole body. Restricted groups had reduced (P < .01) specific activities of jejunal alkaline phosphatase and pancreatic trypsin, amylase, and lipase as compared with the C group at 14 d of age but not at 21 and 42 d of age. Relative activities for jejunal maltase and sucrase were greater (P < .01) at 21 d of age in the R4 and R7 groups than in the C group. The present data show that feed restriction results in transient changes in organs and activities of digestive enzymes, suggesting a functional adaptation to feed restriction.
Poult Sci 1995 Sep
PMID:Effect of early nutrient restriction on broiler chickens. 2. Performance and digestive enzyme activities. 750 92

Two studies using broiler chicks and one using adult White Leghorn roosters were conducted to determine the influence of stachyose and raffinose (alpha-galactosides of sucrose) present in soybean meal (SBM) on the nutritional value of the meal. In Experiment 1, the addition of four levels (0, .05, .10, or .20 g/kg) of alpha-galactosidase with and without 1 g/kg of invertase to a corn-SBM diet had no effect on weight gain, feed efficiency, protein digestibility, or the digestible energy value of the feed when fed to broiler chicks. However, both enzymes decreased (P < .001) dietary AMEn. In Experiment 2, ethanol extraction and incubation of SBM with alpha-galactosidase decreased the concentrations of the alpha-galactosides of sucrose in SBM from 6.59 to .81 and 1.43%, respectively. However, when broiler chicks were fed semi-purified diets containing SBM, ethanol-extracted SBM, water-incubated SBM, or water plus alpha-galactosidase-incubated SBM, no improvements in weight gain, feed efficiency, or apparent protein digestibility were observed. There was also no improvement in TMEn when the above meals were precision fed to adult White Leghorn roosters (Experiment 3). These results indicate that the removal of up to approximately 90% of the alpha-galactosides of sucrose has no beneficial effect on the nutritional value of SBM for chickens.
Poult Sci 1995 Sep
PMID:Removal of the alpha-galactosides of sucrose from soybean meal using either ethanol extraction or exogenous alpha-galactosidase and broiler performance. 750 93

Cadmium compounds are found widely in our environment: for example, in food, water, soil, and ambient air. The most important exposure route of animals to cadmium in the general environment is via oral exposure. In oral cadmium intoxication, the immediate target organ is the gastrointestinal tract. The aim of the present work was to determine how cadmium acts on the intestinal absorption of sugars and on the sucrase activity through rabbit jejunum, after in vitro administration and/or oral administration of CdCl2 in drinking water. Results obtained show that cadmium decreases D-galactose accumulation in the jejunum tissue. This effect seems to be the results of an action mainly located on Na(+)-dependent sugar transport of the mucosal border of the intestinal epithelium, because cadmium seems not to modify the sugar diffusion across the intestinal epithelium. Cadmium has also been shown to inhibit the (Na(+)-K+)-ATPase activity of the enterocyte, which might explain the inhibition of the D-galactose Na(+)-dependent transport. Nevertheless, a direct action of the cadmium molecule on the Na(+)-dependent carrier cannot be discarded. Cadmium altered the sucrose activity when it was administered in the drinking water for 4 d.
Biol Trace Elem Res 1993 Sep
PMID:Effect of cadmium on enzymatic digestion and sugar transport in the small intestine of rabbit. 750 39

The activities of amylase, total proteases, monoglyceride lipase, glycyl-leucine dipeptidase and sucrase were investigated in mucosa from five consecutive parts of small intestine in blue fox, mink, ferret and rat. In comparison with rats, the activity gradient of carbohydrates and TPA in mucosa of predatory animals was shifted in the distal direction. The distribution of dipeptidase and monoglyceride lipase along the intestine was similar enough in all animals: the first was exemplarily the same all along the gut, while the second slightly decreased in a distal direction.
Comp Biochem Physiol A Physiol 1995 Sep
PMID:Distribution of digestive enzyme activities along intestine in blue fox, mink, ferret and rat. 755 36

Glycosylphosphatidylinositol (GPI)-anchored membrane proteins are synthesized by the posttranslational attachment of a preformed glycolipid to newly made glycoproteins. alpha-Agglutinin is a GPI-anchored glycoprotein that gets expressed at the cell surface of MAT alpha cells after induction with type a mating factor. Mutants affecting the biosynthesis of GPI anchors were obtained by selecting for the absence of alpha-agglutinin from the cell wall after induction with a-factor at 37 degrees C. 10 recessive mutants were grouped into 6 complementation classes, gpi4 to gpi9. Mutants are considered to be deficient in the biosynthesis of GPI anchors, since each mutant accumulates an abnormal, incomplete GPI glycolipid containing either zero, two, or four mannoses. One mutant accumulates a complete precursor glycolipid, suggesting that it might be deficient in the transfer of complete precursor lipids to proteins. When labeled with [2-3H]inositol, mutants accumulate reduced amounts of radiolabeled GPI-anchored proteins, and the export of the GPI-anchored Gas1p out of the ER is severely delayed in several mutant strains. On the other hand, invertase and acid phosphatase are secreted by all but one mutant. All mutants show an increased sensitivity to calcofluor white and hygromycin B. This suggests that GPI-anchored proteins are required for the integrity of the yeast cell wall.
J Cell Biol 1995 Sep
PMID:Identification of six complementation classes involved in the biosynthesis of glycosylphosphatidylinositol anchors in Saccharomyces cerevisiae. 755 56

All the non-pathogenic strains of Escherichia coli tested failed to synthesize invertase. However, among the pathogenic E. coli, only 11% of them synthesized the enzyme. Invertase synthesis was best at pH 8.0, when the sole nitrogen source was peptone. The enzyme was induced by sucrose but repressed by glucose and fructose. The enzyme was partially purified by ammonium sulphate precipitation, followed by dialysis and gel permeation chromatography. The partially purified invertase possessed a molecular weight of 125,000 KD and an apparent km of approximately 2.94mM for sucrose. The enzyme was stimulated by Ca++ and Mg++, inhibited by Cu++, U++, IAA and exhibited optimum activity at pH 6.5 at 40 degrees C.
Afr J Med Med Sci 1994 Sep
PMID:The purification and characterization of intracellular invertase obtained from pathogenic Escherichia coli. 760 57

Differentiated villus intestinal epithelial cells express globotriaosylceramide, the Shiga-like toxin 1 (SLT-1) receptor, and are sensitive to toxin-mediated cytotoxicity, whereas undifferentiated crypt cells neither express Gb3 nor respond to toxin. To investigate if SLT-1 receptors are maturationally regulated in human intestinal cells, we examined the effect of butyrate, a known transcriptional regulator of differentiation genes in many cell types, using cultured colonic cancer-derived epithelial cell lines. Exposure to butyrate increased villus cell marker enzymes such as alkaline phosphatase, sucrase, and lactase, expression of toxin receptors, and sensitivity to SLT-1 in villus-like CaCo-2A and HT-29 cells. These effects were reversibly inhibited by preincubation of CaCo-2A cells with actinomycin D or cycloheximide. Butyrate-treated CaCo-2A cells unable to bind fluoresceinated SLT-1 B subunit were undifferentiated as assessed by alkaline phosphatase activity. HT-29 cells induced to differentiate by another signal, glucose deprivation, upregulated receptor content and response to toxin. Crypt-like T-84 cells responded to butyrate with a modest increase in alkaline phosphatase and toxin binding, but no induction of sucrase or lactase, and no change in sensitivity to toxin. The results demonstrate that expression of SLT-1 toxin receptors and toxin sensitivity are coregulated with cellular differentiation in cultured intestinal cells.
J Clin Invest 1995 Sep
PMID:Maturational regulation of globotriaosylceramide, the Shiga-like toxin 1 receptor, in cultured human gut epithelial cells. 765 8

A constitutive invertase (EC 3.2.1.26) was isolated and purified by the first time from Pycnoporus sanguineus. The enzyme is a glycoprotein. Its relative molecular mass is about 84,000 and its structure is dimeric, with two identical subunits (about 41,000). The enzyme is able to attack sucrose, raffinose, stachyose, inulin and levan, being sucrose the preferred substrate (Km 4.89 +/- 0.13 mM). Fructose was a classical competitive inhibitor, but glucose was not an inhibitor of the enzyme. Lectins with specificity toward glucose are inhibitors of the enzyme. Glucose was present in invertase acid hydrolysates. Unlike higher plant invertases, bovine serum albumin is not an effector of the Pycnoporus sanguineus enzyme, and the inhibition by fructose is not suppressed by this protein. The properties of the Pycnoporus sanguineus enzyme are discussed with reference to higher plant invertases.
Biochim Biophys Acta 1995 Sep 06
PMID:Purification and characterization of the invertase from Pycnoporus sanguineus. 766 14

Isatin (15-25 mM) inhibited rat brush border sucrase by 40% in presence of Na+ and the inhibition was enhanced to over 60% in sodium free medium. Sucrase inhibition by isatin was dependent on pH. Kinetic analysis revealed a pure capacity type (Vmax-effect) inhibition of sucrase activity by isatin in presence of sodium. But it changed to affinity type (K-effect) in sodium free medium. The value of Ki was around 20-25 mM under these conditions. Enzyme inhibition by isatin was alleviated by increasing Na+ or sucrose concentrations. Other monovalent cations like K+, Li+ and Cs+ were also effective in restoring the enzyme activity to control levels. The effectiveness of the metal ions in alleviating the enzyme inhibition was in the order of Na+ > Cs+ > K+ > Li+.
Indian J Exp Biol 1994 Sep
PMID:Inhibition of brush border sucrase by indoline 2,3-dione (isatin) in rat small intestine. 781 38


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