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)

A genetically conditioned mouse model of exocrine pancreatic insufficiency (epi) has been used to study the effect of the absence of lumenal proteases on small intestinal mucosal proteins. The small bowel was divided into eight equal segments. Enzyme activity was increased only in the first three segments in the case of maltase, sucrase, and lactase (all mol wt above 200,000). Alkaline phosphatase (mol wt 145,000), trehalase (mol wt 95,000), and peptidase (mol wt 175,000) activities were unaffected in proximal segments from epi mice. Proximal brush border proteins were identified and measured quantitatively by sodium dodecyl sulfate acrylamide gel electrophoresis. Those enzymes with increased activity were associated with increased amounts of protein in epi mice. Double labeled studies of protein turnover revealed a longer half-life for large brush border proteins (mol wt above 175,000) in epi mice than in normal mice. Enterokinase activity (a marker for duodenal mucosa) was nearly absent from the duodenum of epi mice. Receptors for the intrinsic factor-vitamin B12 complex (markers for ileal mucosal) were present in the ileum equally in normal and in epi mice. Enterokinase activity can be induced in epi mice by feeding its substrate trypsinogen, but not by trypsin or chymotrypsinogen. Epi mice thus retain the ability to synthesize enterokinase. Pancreatic proteases play an important role in the turnover of certain large mucosal proteins and in the induction of enterokinase.
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PMID:Effect of exchange exocrine pancreatic insufficiency on small intestine in the mouse. 20 83

In order to elucidate a possible relationship between (Na+ + K+)-activated ATPase and intestinal absorption of actively transported monosaccharides enzyme activity was measured in mucosal cells from alloxan diabetic rats. The general effect of increasing capacity of active, Na+-dependent transport processes in diabetes mellitus is associated with a significantly enhanced (Na+ +K+)-activated ATPase activity in mucosal homogenate from diabetic animals. To study the localization of these effects within the cell we isolated purified brush borders and their substructures. To enable a comparison to be made between preparation procedures of diabetic and control animals the fractions were controlled by electronmicroscopy and by measuring the sucrase activity. In the purified brush border fraction of alloxan treated rats there was no significant increase in (Na+ + K+)-activated ATPase activity. Based on these results we conclude that the (Na+ + K+)-activated ATPase in the basolateral membranes was increased in alloxan diabetes, and it seems very likely that this enzyme is involved in the regulation of Na+-dependent transport processes.
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PMID:[Effect of alloxan diabetes on (Na+ + K+)-activated ATPase in brush border membrane of the mucosal cell of rat small intestine]. 21 7

The postition of a number of human intestine brush border membrane enzyme activities in polyacrylamide gels after electrophoresis has been determined. These activities are, in order from the origin, maltase/glucoamylase, lactase/phlorizin hydrolase, maltase/sucrase/isomaltase, enteropeptidase, trehalase and gamma-glutamyl-transferase. Leucylnaphthylamide hydrolyzing activity was inactivated by sodium dodecylsulfate and its position was not determined. The positions of the activities have been correlated with the positions of protein bands previously determined. One such band situated between enteropeptidase and alkaline phosphatase has not been identified.
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PMID:Enzymes of the human intestinal brush border membrane. Identification after gel electrophoretic separation. 23 25

Leucine beta-naphthylamidase associated with the microvilli membranes of rabbit small intestine was solubilized with papain [EC 3.4.22.2] and purified by Sephadex G-200 gel filtration, DEAE-cellulose column chromatography, passage through a column of Sepharose 4B coupled with anti-sucrase antibodies and preparative disc electrophoresis in polyacrylamide gel. The purified enzyme was homogeneous on ultracentrifugation and disc electrophoresis, but a double immunodiffusion test showed the presence of a minor component which was probably denatured enzyme. The molecular weight of the purified enzyme was estimated to be 225,000 by Sephadex G-200 gel filtration and the sedimentation coefficient (S-0-20, w) was found to be 6.90S. Purified enzyme required bovine serum albumin for maximal activity, perhaps for its protection from autodigestion. It hydrolyzed, in addition to L-leucine beta-naphthylamide, various L-amino acid beta-naphthylamides and dipeptides with a free alpha-amino group, but did not hydrolyze benzoyl-L-arginine beta-naphthylamide. Therefore, the purified enzyme is an aminopeptidase. Hg-2+ and Cu-2+ ions strongly inhibited the enzyme activity, but other metal ions and EDTA showed no or only slight effect. N-Ethylmaleimide exhibited a weak inhibition. Purified enzyme had an optimal pH and Km value for leucine beta-naphthylamide similar to those of enzymes from other sources. Antibodies against the purified enzyme were raised in guinea pigs. The antibodies obtained were found by double immunodiffusion to be specific for the enzyme. They precipitated the enzyme quantitatively and partially inhibited the enzyme activity.
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PMID:Purification and properties of leucine beta-naphthylamidase from rabbit small-intestinal mucosal cells. 23 93

The activities of rat intestinal enzymes, sucrase, lactase, maltase, trehalase, gamma-glutamyltransferase, leucylnaphthylamide-hydrolyzing activity, and the transport system for glucose follow diurnal rhythms on ad libitum and restricted feeding regimes. In response to 6 days of restricted feeding, food available between 1400 and 1800 Eastern Standard Time, all rhythms shifted in time and the daily levels of activities were changed. Alkaline phosphatase activity followed a diurnal rhythm only in restricted fed animals. In restricted fed rats several activity patterns were observed, some with short periods of maximum activity, 3 h or less, and some with plateaus of maximum activity, 5-9 h long. In respect to the time of day of the synchronizer, sucrase peaked before feeding, glucose transport peaked during feeding, alkaline phosphatase peaked after feeding, and the other enzymes had higher levels of activity before, during and after feeding. The effect of restricted feeding on the daily activity levels were: a decrease in leucylnaphthylamide-hydrolyzing activity, no change in alkaline phosphatase, and increases in the others. These enzyme and transport systems exhibit a large amount of individual regulation or control as reflected by the lack of a uniform activity pattern and response to the synchronizer, and the variation in direction and magnitude of the adaptations to restricted feeding.
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PMID:Effect of changes in feeding schedule on the diurnal rhythms and daily activity levels of intestinal brush border enzymes and transport systems. 24 Apr 40

The first part of the paper deals with the effect of changes in the mother's hormonal status on the development of the small intestine of her offspring. Administration of cortisone or triiodothyronine (T3) to pregnant rats evokes a precocious appearance of sucrase activity in the fetal small intestine. Administered to lactating rats, T3 evokes a precocious increase in sucrase activity in sucklings and leads to increased T3 levels and decreased TSH levels in the mother's milk and in sera of mothers and sucklings. These experiments show that (a) sucrase activity can be induced in the fetal period; (b) changes in the mother's hormonal balance during the fetal and suckling period can influence the development of the small intestine; and (c) levels of thyroid hormones in milk can be altered experimentally. The second part deals with jejuno-ileal gradients in villus size and sucrase activity. Both gradients appear in fetal jejunal and ileal implants developing in adult hosts. Our experiments indicate that (a) the gradients are already 'programmed' during the fetal period; and (b) direct contact with food, and proximity of the jejunum to the flow of digesta from the stomach, are not decisive for expression of the jejuno-ileal gradients, but may play a 'tuning' role.
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PMID:Development of sucrase activity: effect of maternal hormonal status and fetal programming of jejuno-ileal differences. 26 19

The effects of corticosteroid have been studied in rats submitted to oral administration of prednisone (5 mg. per kg. per day) during 8, 15, 30, and 90 days. The results were compared to those obtained after parenteral administration of hydrocortisone acetate (50 mg. per kg. per day intramuscularly). The morphometric changes of the villus-crypt axis and the brush border enzymic content of the mucosa (sucrase, enterokinase, alkaline phosphatase, and aminopeptidase) were the parameters investigated at the duodenal, jejunal, and ileal levels. Oral administration of prednisone resulted in a significant increase of the duodenal villous height at the 15th (+ 13 per cent, p less than 0.01), 30th (+ 33 per cent, p less than 0.001), and 90th day (+ 56 per cent, p less than 0.001), whereas in the jejunum a constant decrease of the villous height was noted. Parenteral hydrocortisone administration did not affect intestinal morphology. Effects of oral corticosteroids on the microvillous enzymic activities were related to both intestinal level and duration of corticoids administration: (1) in the duodenum increase of sucrase, alkaline phosphatase, and aminopeptidase during 30 days followed by normalization at the 90th day, (2) an initial increase of sucrase, alkaline phosphatase, and aminopeptidase limited to the first 8 days in the jejunum, and (3) a significant rise of alkaline phosphatase (greater than 100 per cent, p less than 0.001) and enterokinase (greater than 100 per cent, p less than 0.001) in the ileum at the 15th day of treatment. Parenteral corticosteroid administration was associated with a significant increase of both sucrase and enterokinase activities. The present study suggests that: (1) Corticosteroids exert a direct effect on the intestinal morphology varying with the intestinal level and duration of treatment. (2) No correlation could be established between anatomic and functional changes. (3) Oral corticosteroids exert an enhancing effect of the brush border enzymic activities, even in the adult mucosa and particularly at the ileal level where they stimulate significantly the enterokinase mucosal activity. (4) Parenteral corticosteroids exert a more specific effect limited to sucrase and enterokinase enhancement.
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PMID:Effects of oral and parenteral corticosteroids on intestinal villous morphology and brush border enzymes in the rat. 31 75

Electron microscopy and cytochemical and immunocytochemical procedures were used to study the ultrastructural distribution of sucrase enzymes in two strains of Streptococcus mutans. In a strongly adherent and virulent parent strain, GS-5, most of the invertase and fructosyltransferase activities were demonstrated extracellularly or bound to the cell surfaces. Intracellularly, enzymatic sites were detected near the plasma membrane on the periphery of the nucleoid and central mesosome. In GS-511, a mutant of diminished virulence and adherence, most of the enzymatic activity was not located on the cell surfaces, but was found away from the cell walls and associated with extracellular polysaccharides. Intracellularly, GS-511 manifested the same distribution of invertase and fructosyltransferase as did GS-5; however, the close association of these enzymes with the plasma membrane was not shown in GS-511. In both strains, extracellular areas near regions associated with cross wall formation appeared to show localized concentrations of these sucrases. Antibodies against partially purified glucosyltransferase (GTF) enzymes from GS-5 were used to localize GTF by immunocytochemical techniques. Indirect ferritin localization procedures showed that the extracellular and cell-bound GTF enzymes were distributed in similar locations as the fructosyltransferase and invertase enzymes. By absorption of the antiserum with whole GS-511 cells, the location of extracellular GTF and surface antigens unique to GS-5 was demonstrated. The dramatically reduced levels of cell-bound sucrase activity in GS-511 indicates the significant role of these enzymes in adherence and cariogenicity.
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PMID:Ultrastructural localization of sucrases in Streptococcus mutans GS-5 and an extracellular polysaccharide mutant: a comparative cytochemical and immunocytochemical study. 33 Apr 13

The release of proteins, sucrase (SA), maltase (MA), leucine aminopeptidase (LA) and alkaline phosphatase (AP) activity from rat jejunum by sodium deoxycholate (DOC) was studied by an in vivo perfusion technique. In our experimental conditions, a 2 mmol/1 DOC perfusion for 30 min induced a marked and reversible release of proteins and hydrolases. When specific activities were considered, each enzyme showed a distinct release pattern. Significantly, the SA release was largely increased, the AP release was decreased and there was no correlation between the releases of SA and AP. Furthermore, the various enzymes recovered into the lumen were solubilized at different extents. SA was chiefly present in a soluble and AP in a particular form. The microscopical appearances showed a slight exfoliation of the epithelial cells from the villous tips but no specific changes when compared to the control group. The results are discussed in terms of enzymic localization in the brush border membrane; SA would be located very superficially in the surface membrane and AP buried in the membrane and less accessible than the other enzymes.
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PMID:Rat intestinal brush border enzymes release by deoxycholate in vivo. 34 19

Brush border membrane bound disaccharidases (sucrase and maltase) and lysosomal enzyme (alpha-glucosidase, beta-D-fucosidase and N-acetyl-beta-glucosaminidase) activities awere studied in amniotic fluid (AF). The above enzymes except N-acetyl-beta-glucosaminidase showed a decrease in activity with gestational age beginning at about the 19th week. The activities of sucrase and maltase correlate with the morphological maturation of fetal intestinal mucosa. The distribution of disaccharidases and lysosomal alpha-glucosidase in AF and intestinal mucosa showed different patterns suggesting that these enzymes originate in diverse fetal tissues.
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PMID:Disaccharidase and lysosomal enzyme activities in amniotic fluid, intestinal mucosa and meconium. Correlation between morphology and disaccharidase activities in human fetal small intestine. 34 69


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