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)

Among 135 infants and children with a supposed malabsorption syndrome, a deficiency of isomaltase-saccharase of the duodenal mucosa was detected in 5 cases by measuring the disaccharidases directly in the mucosa homogenate. In one instance a deficiency of lactase was found in addition. In all patients the villi were of normal length, with an increased cell infiltration of the stroma detected in two cases. The loading tests with xylose-sucrose yielded a diminuished rise in the blood glucose level. Three of the patients were dwarfish, but only one showed an increased growth after the reduction of sucrose in the supplied diet. As a result of adaptation difficulties in the change of diet, one patient had to be treated with an additional saccharase substitution.
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PMID:[Hereditary deficiency of isomaltase and saccharase responsible for a malabsorption syndrone (author's transl)]. 116 88

In 63 infants and children with a histological normal mucosa of the duodenum, without an isolated defect of enzyme and with a normal increase of xylose and glucose in serum after a combined xylose-lactose loading test the activities of disaccharidases were log normal distributed. The asymmetric distributions were transformed into symmetric ones and the geometric mean (x) as well as the range (+/- 2 s) of maltase, saccharase, isomaltase, lactase and trehalase were calculated. Only the activity of lactase shows a significant dependency on age. In the first year of age the lower limit (x -- 2 s) of this enzyme is much higher than later.
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PMID:[Disaccharidases of the small intestine mucosa in infants and children. "Normal values", log normal distribution and age dependence]. 122 50

Soluble beta-fructofuranosidase with an intracellular location and an isoelectric point of 3.8 (isoenzyme I) was purified and characterized from dry seeds and seedlings of carrot (Daucus carota). The enzyme hydrolyzed sucrose with a Km of 5 mM and a broad pH optimum around 5.0. The purified protein, which was N-glycosylated with high-mannose-containing and high-xylose-containing complex glycans, eluted as a monomeric polypeptide with a molecular mass of 68,000 from a gel-filtration column. On SDS/PAGE, the protein separated in the presence of SDS and 2-mercaptoethanol into three polypeptides with molecular masses of 68, 43 and 25 kDa. The amount of the 68-kDa polypeptide was highest in dry seeds and decreased with increasing age of carrot seedlings. Amino acid sequence analysis and immunological studies showed that the 43-kDa and 25-kDa polypeptides were N-terminal and C-terminal proteolytic fragments of the 68-kDa polypeptide. A comparison of partial amino acid sequences of the soluble beta-fructofuranosidase with the complete sequence of carrot cell-wall beta-fructofuranosidase showed that their N-terminal sequences were different, whereas some of the internal tryptic peptide sequences were up to 70% identical.
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PMID:Purification and characterization of a soluble beta-fructofuranosidase from Daucus carota. 154 2

Six litters of newborn crossbred piglets were utilized to examine 1) the effects of substituting 20% of the protein of an all-milk protein liquid diet with a soy protein isolate (milk-soy diet) on small intestinal variables and 2) the effects of supplementing this milk-soy diet with 25 g of either putrescine or ethylamine per kilogram diet on small intestinal variables. Small intestinal xylose absorption tended to increase from wk 1 to wk 2 of age in pigs fed the milk, putrescine and ethylamine diets, but not in pigs fed the milk, putrescine and ethylamine diets, but not in pigs fed the unsupplemented milk-soy diet. Crypt depth in pigs fed the milk-soy diet tended to be less (9.4%; P greater than .10) than the crypt depth in pigs fed the other diets, but mitotic index was not different (P greater than .10) among diets. Mucosal protein, DNA and RNA concentrations and mucosal brush border sucrase and cytosolic dipeptidase activities tended to be least in pigs fed the putrescine and ethylamine diets. Concentration of mucosal putrescine was greatest (P less than .002) in the distal regions of the small intestine of pigs fed putrescine. Mucosal ornithine decarboxylase activity was inhibited by putrescine (P less than .02), but it was not affected by the soybean protein isolate used in this study. Supplementing soy protein isolate diets with amines may enhance intestinal absorption and enterocyte proliferation.
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PMID:Effects of dietary amines on small intestinal variables in neonatal pigs fed soy protein isolate. 169 Jan 99

Aspergillus nidulans produces an extracellular beta-D-fructofuranoside fructohydrolase (invertase) when grown on a medium containing the beta-fructofuranosides sucrose or raffinose, indicating that synthesis is subject to induction by the substrate. On a growth medium containing sucrose, production was maximal at 15 h in cultures incubated at 28 C degrees. After this time the level of detectable invertase in the cultures declined. A proportion of the enzyme was secreted during the linear growth phase of the fungus. Various sugars were investigated for induction of invertase, but only the two beta-fructofuranosides induced high production levels; with the other sugars, the enzyme was produced only at a low constitutive level. Mycelium grown under repressive conditions (1% glucose), rapidly produced invertase when transferred to sucrose-containing medium. After 80 min the invertase level in these cultures was 26-fold higher than the constitutive level. The repressive effect of other sugars, e.g. glucose and xylose, on invertase production was also demonstrated in this experimental system.
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PMID:Regulation of invertase in Aspergillus nidulans: effect of different carbon sources. 201 86

The N-linked glycans from the 52/54-kDa medium protein and cell wall beta-fructosidase, two glycoproteins secreted by carrot suspension culture cells, were characterized. Carrot cells were labelled with [3H]glucosamine or [3H]fucose. The 52/54-kDa medium protein was isolated from the culture medium and beta-fructosidase from cell walls. The purified proteins were digested with trypsin and glycopeptides were isolated and sequenced. Glycans obtained from individual glycopeptides were separated by gel filtration chromatography and characterized by concanavalin A chromatography, by treatments with exoglycosidases and by sugar composition analysis. The 52/54-kDa medium protein and cell wall beta-fructosidase have one high-mannose-type glycan similar to those from yeast and animal glycoproteins. In addition, the 52/54-kDa medium protein has three complex-type and cell wall beta-fructosidase two complex-type glycans per polypeptide. The complex-type glycans isolated from individual glycosylation sites are fairly large and very heterogeneous. The smallest of these glycans has the structure [Xyl](Man)3[Fuc](GlcNAc]2Asn (square brackets indicating branching) whereas the larger ones carry additional sugars like terminal N-acetylglucosamine and possibly rhamnose and arabinose in the case of the 52/54-kDa medium protein and only arabinose in the case of cell wall beta-fructosidase. These terminal sugars are linked to the alpha-mannose residues of the glycan cores. The 52/54-kDa medium protein is secreted with large and homogeneous complex glycans, their heterogeneity originates from slow processing after secretion. The complex glycans from cell wall beta-fructosidase are processed before the enzyme is integrated into the cell wall.
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PMID:Heterogeneity of the complex N-linked oligosaccharides at specific glycosylation sites of two secreted carrot glycoproteins. 206 72

The activities of the enterocyte brush border enzymes lactase (beta-D galactoside galactohydrolase, EC 3.2.1.23) and sucrase (sucrose alpha-D glucohydrolase, EC 3.2.1.48) were measured at set percentage lengths along the small intestines of 112 piglets killed between 21 and 32 days of age. The influences on these activities of consumption of creep feed and of weaning were recorded. Weaning at three weeks old resulted in large, rapid reductions in lactase activity at most sites along the small intestine; sucrase activity declined temporarily and then recovered. Minimum values were recorded about four to five days after weaning. Similar changes were observed whether or not creep feed was consumed before weaning. Continued consumption of creep feed by unweaned pigs over the 21 to 32 day period also produced small but significant reductions in lactase activities. The large loss of digestive enzyme activities at brush borders in weaned animals coincided with a reduced ability to absorb xylose and to checks in growth rate in otherwise healthy piglets.
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PMID:Influence of creep feeding and weaning on brush border enzyme activities in the piglet small intestine. 308 80

The results of studies on disaccharidase activities and on intestinal absorption in cases of complete and incomplete congenital small bowel obstruction are presented. Assays of the activities of maltase, isomaltase, sucrase, trehalase, and lactase have been performed on biopsy specimens taken at the time of surgery. In specimens taken from above the site of obstruction, the activities are reduced for all disaccharidases, and are particularly low for trehalase and lactase. There was no difference between the cases with complete and incomplete obstruction. Distal to a complete obstruction, trehalase and lactase were reduced, whereas in cases of incomplete obstruction, the activities of all disaccharidases were within what is considered normal in the reference material. Two months after surgery, the disaccharidase activities were found to be normal. One month after surgery, the absorption of glucose and vitamin A was markedly impaired in cases with complete obstruction, whereas that of D-xylose was not significantly reduced from normal. In cases with incomplete obstruction, the results did not differ from those found in normal infants. The fact that failure to thrive is common during the first months after birth in patients with congenital intestinal atresia, even when surgery is successful, may be explained by deficient intestinal absorption, particularly in patients with complete obstruction.
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PMID:Disaccharidase activities and intestinal absorption in infants with congenital intestinal obstruction. 312 31

Although Strongyloides stercoralis is a common parasite, little is known about its effect on intestinal function. Published clinical studies are difficult to evaluate and compare because of the inability to differentiate the effects of the parasite load from that of various other coexisting features such as bacterial overgrowth, multiparasitism, malnutrition, or tropical sprue. Using a rat model where these problems do not occur, we found that Strongyloides ratti did not inhibit intestinal function in the healthy rat. In fact, in normal rats S. ratti appeared to increase ileal sucrase activity. In contrast, in the methylprednisolone-treated rat, S. ratti produced a decrease in lactase and sucrase activity and an increase in alkaline phosphatase activity. S. ratti had no effect on 3-O-methylglucose uptake or D-xylose absorption in either group. These results suggest that S. ratti has little effect on small bowel function in a healthy rat but can cause minor alterations in intestinal function in an immunosuppressed, methylprednisolone-treated, malnourished host. These results are also consistent with clinical observations seen with S. stercoralis in humans and with another nematode, Ascaris suus, in the pig model.
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PMID:Effect of Strongyloides ratti on small bowel function in normal and immunosuppressed host rats. 313 82

The mechanism of inactivation of hexokinase PII of Saccharomyces cerevisiae by D-xylose was characterized. Inactivation was dependent on the presence of MgATP and was irreversible. Inactivation involved phosphorylation of the protein. Observation of the carbon catabolite repression of selected enzymes showed that invertase and maltase synthesis were not repressed when hexokinase PII was phosphorylated.
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PMID:Mechanism of inactivation of hexokinase PII of Saccharomyces cerevisiae by D-xylose. 330 37


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