Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:3.2.1.20 (alpha-glucosidase)
 4,237 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Treatment of renal brush-border membrane vesicles with papain resulted in the removal of the activity of maltase, gamma-glutamyl transpeptidase and leucine aminopeptidase by 85, 50 and 75%, respectively. Stripping of these membrane enzyme activities constituted about 2% of the total membrane proteins and resulted in a widespread diminution in the ability of a variety of amino acids and sugars to be taken up by the membrane vesicles which remained osmotically responsive. Kinetic analysis of the uptake of proline, which was shown previously to be transported by both sodium-dependent and sodium-independent systems, revealed that the Vmax for the sodium-dependent system and Km for the sodium-independent system were halved, but other parameters were not affected indicating that the papain treatment altered sodium-gradient-stimulated entry and the affinity of the sodium-gradient-independent system for proline. Experiments on sodium entry and efflux demonstrate a marked enhancement of flux, so that equilibration of the sodium gradient occurred about 5-times more rapidly than in untreated vesicles. This occurred without any change in the osmotic properties of the vesicle with regard to sodium or amino acid uptake. Studies of fluorescence polarization suggest that incubation with papain does not alter the lipid domains of the membrane.
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PMID:The effect of papain upon proline and sodium transport of rat renal brush-border membrane vesicles. 613 97

The present investigations on rat lung show that metabolic changes occurring around the 20th gestational day are accompanied by multiple alterations in the quantitative pattern of enzymes. This involves increases in two lysosomal enzymes (N-acetyl beta-glucosaminidase and beta-galactosidase) and a rise and fall in pyruvate kinase and alpha-glucosidase. The striking transient upsurge of adenylate kinase, however, is postponed until after birth. The normal diminution of thymidine kinase and peptidylproline hydroxylase is drastically enhanced by an injection of cortisol to fetal rats. Studies on human pulmonary tissues consisted in determining enzyme concentration from the ninth to the 21st week of gestation and an histologically normal adult lungs. The results show that the 15th to the 21st week of gestation is the period of increase in pyruvate kinase, adenylate kinase and alpha-glucosidase. The rise during the development of several enzymes (e.g., 5'-nucleotidase, alkaline phosphatase, and gamma-glutamyl transpeptidase) and the decline in thymidine kinase and peptidylproline hydroxylase, however, dose not begin until after the 21st week of gestation.
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PMID:Phosphotransferases and lysosomal enzymes in fetal human and rat lung. 626 41

Membrane proteins can be attached to the plasma membrane in several ways. Recently, a mechanism has been described, by which a number of cell surface proteins are anchored to the exoplasmic side of the plasma membrane by covalent linkage to glycosyl-phosphatidylinositol (GPI). The growth properties of renal epithelial cells in tissue culture enable free access to apical cell surface and brush border membrane proteins. To study the nature of membrane anchoring of apical plasma membrane enzymes in cultured renal epithelial cells, confluent LLC-PK1, OK, NRK, and MDCK epithelia were treated in tissue culture dishes with bacterial phosphatidylinositol-specific phospholipase C (PI-PLC), and the PI-PLC-specific release into the tissue culture medium of the apical membrane enzymes alkaline phosphatase (AP), gamma-glutamyl transpeptidase, leucine aminopeptidase, trehalase, and maltase was determined. Of the five enzymes tested, AP and trehalase, already described as GPI-anchored membrane proteins, were specifically released by PI-PLC from intact cell monolayers. Of the four cell lines investigated, LLC-PK1 cells express AP and trehalase which were released by PI-PLC. In OK cells, which lack AP activity, only trehalase was found to have PI-PLC-releaseable enzyme activity. MDCK cells, on the other hand, express AP activity, releaseable by PI-PLC, but no trehalase activity. In studies on the time course of synthesis and reinsertion of AP into the apical membrane of LLC-PK1 cells after removal by PI-PLC, a 60% recovery of AP activity was obtained only after 7 days. Analysis of protein release by sodium dodecyl sulfate-polyacrylamide gel electrophoresis of culture supernatants after surface labeling with biotin and subsequent Western blotting with streptavidin revealed four protein bands at approximately 130, 90, 30, and 20 kD in LLC-PK1 cells and five GPI-anchored proteins at 110, 85, 65, 40, and 26 kD in OK cultures. The finding of a PI-PLC-specific release of apical membrane enzymes from renal tubular cell lines of different species (pig, opossum, rat, and dog) and of different nephron origin indicates a high conservation of the GPI anchor of renal brush border membrane proteins and further proves the high degree of differentiation retained by the cell lines in tissue culture. In addition, this method may provide a possible tool for isolating GPI-anchored apical membrane proteins from intact epithelial monolayer cultures.
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PMID:Selective release of apical membrane enzymes from cultured renal epithelia by phosphatidylinositol-specific phospholipase C. 750 39

To determine whether incorporation of peptides into diets can improve larval development, sea bass (Dicentrarchus labrax) larvae were fed for 21 d one of three isonitrogenous, isoenergetic semipurified diets in which enzymatic hydrolysate (75% di- and tripeptides) of fish meal proteins was substituted for 0, 20 or 40% of native fish meal proteins. Growth and survival were significantly greater (P < 0.05) in larvae fed peptide diets compared to those fed only native protein, with the best performance exhibited by those fed the 20% level of peptides. Chymotrypsin activity was much higher in groups fed peptide diets compared to that fed all native protein (P < 0.001), indicating a greater proteolytic capacity of the pancreas. At the intestinal level, activities of the brush border enzymes, aminopeptidase, maltase and gamma-glutamyl transpeptidase, increased with age while the cytosolic enzyme, leu-ala peptidase, decreased with age (P < 0.001). These changes in enzymatic activities correspond to the normal development of intestinal digestion. This development occurred earlier in the group fed 20% peptide-substituted diet than in the two other groups. The better larval performances observed in groups fed diets containing peptides can be related to the enhanced proteolytic capacity of the pancreas and the earlier development of intestinal digestion.
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PMID:Partial substitution of di- and tripeptides for native proteins in sea bass diet improves Dicentrarchus labrax larval development. 910 12

Intestinal ischemia necessitates rapid re-establishment of blood flow to prevent irreversible anoxic tissue damage. However, reperfusion results in additional injury as a consequence of the generation of oxygen free radicals. To date, no clear-cut marker to differentiate between ischemia versus reperfusion injury is available. In this regard, previous studies from our laboratory utilizing a rat in vitro lipid peroxidation model demonstrated that the generation of free radicals resulted in the inactivation of only the intestinal brush border alkaline phosphatase enzyme, with no effect on other membrane-bound digestive enzymes. Current studies were designed to assess the possibility of alkaline phosphatase being a specific marker of the reperfusion injury in canine and human ex vivo ischemia/reperfusion models. Small bowels harvested from canines and organ donors were subjected to ischemia followed by reperfusion. Brush border membrane enzymes, alkaline phosphatase, sucrase, maltase, and gamma-glutamyl transpeptidase were assayed in mucosal extracts from intestines with ischemia versus reperfusion. In both experimental models, there was no change in any enzyme activity with warm ischemia alone. In contrast, alkaline phosphatase activity was significantly decreased in both the canine and human reperfusion models, with no change in specific activities of sucrase, maltase, and gamma-glutamyl transpeptidase. Our data indicate that the alkaline phosphatase enzyme activity may represent a potential marker of intestinal reperfusion injury and may permit quantitative assessments of therapeutic interventions in human intestinal reperfusion injury.
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PMID:Decrease in mucosal alkaline phosphatase: a potential marker of intestinal reperfusion injury. 1021 63

1. Uptake of triglycerides and phosphoglycerides was demonstrated in ligated washed chick intestinal segments in situ. Mucosal uptake was observed both in the jejunum and ileum of chicks and was not accompanied by significant luminal hydrolysis of acylglycerides. 2. Brush border membrane vesicles were prepared and lipase and phospholipase activities were demonstrated. These activities were enriched in parallel to the increase in activity of maltase and gamma-glutamyl transpeptidase in all small intestinal areas. 3. In order to determine if the pancreatic and brush border membrane lipolytic activities were similar different properties of these activities were examined. The relative activities of pancreatic and brush border membranes towards triolein and phosphatidylcholine differed. The pH-triolein activity curve and the use of different additives showed some diverging effects between the activities. These differences were not, however, sufficient to conclude that the brush border activity towards triolein is distinct from that of pancreatic lipase. 4. Lipolytic activity in the brush border may play a role in acylglyceride digestion, uptake and transport in the small intestine of the chick.
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PMID:Chick small intestine brush border contains lipase and phospholipase activity. 1047 38

Quantitative estimation of urinary enzymes has been advocated as a more sensitive marker than conventional renal function tests to assess radio-contrast media induced nephrotoxicity. We studied 27 subjects with normal renal functions who underwent abdominal aortography for varied indications. Among these, 8 also required selective renal arteriography and 3 underwent arch aortography in addition. Sodium iothalamate was used as a radio-contrast medium and the average amount injected was 73 ml (45 to 120 ml) per subject. Standard renal function assessment including urinalysis, 24 hour urinary protein excretion, creatinine clearance done both before and after aortography did not show any significant alteration. Urinary excretion of tubular enzymes including leucine aminopeptidase (LAP), alkaline phosphatase (ALP), gamma-glutamyl transpeptidase (GGT) and maltase (MAL) was estimated before and 2, 24 and 48 hours after aortography. All enzymes showed a significant rise at 2 hours. Urinary excretion of LAP, ALP and GGT peaked at 24 hours after aortography without a further change in MAL levels. Enzymuria returned to baseline values 48 hours following the procedure. It is concluded that an increase in the urinary excretion of the brush-border enzymes within 24 hours of contrast media administration may suggest an early nephrotoxicity.
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PMID:Quantitative enzymuria following aorto-renal angiography. 1099 87

To examine age-related changes in the morphology of intestinal brush border membrane (BBM; microvilli) and specific activities of intestinal BBM enzymes including alkaline phosphatase (ALP), gamma-glutamyl transpeptidase (gamma-GT), and disacchridase, four groups of Wistar rats were sacrificed at 2.5 wk, 5 wk, 5 mon and 23 mon. In an electron microscopic examination, morphologically a less dense BBM structure in the duodenum of rats aged 23 mon was observed than that of rats aged 5 mon. Specific activity of ALP in the duodenum from 5-mon-old rats was significantly higher than from rats aged 2.5 wk and 23 mon. The mucosal tissues from 5-wk-old rats had significantly higher specific activity of gamma-GT than did tissues from the other ages. In sucrase and maltase specific activities, 5-mon-old rats had higher activities of these enzymes than other age groups, especially 2.5-wk- and 23-mon-old rats. There was also a significant effect of site on intestinal BBM enzyme activities in post-weanling rats. Regional gradients of ALP and gamma-GT along the entire small intestine (duodenum > jejunum > ileum) were remarkable. Disaccharidase activities peaked in the jejunum and declined toward both the duodenum and ileum. Taken together the result obtained here suggested that 5-mon-old rats had the most elevated intestinal function. This result also strongly indicated that the structure of the intestinal BBM and development of intestinal BBM enzymes in Wistar rate were markedly influenced by age during the postnatal period.
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PMID:Influence of age on duodenal brush border membrane and specific activities of brush border membrane enzymes in Wistar rats. 1110 54

The present study was planned to observe the effect of protein-energy malnutrition on the gastric and duodenal mucosa. The activities of digestive enzymes (i.e. lactase, sucrase, maltase, trehalase, glucoamylase, leucine aminopeptidase, alkaline phosphatase and gamma-glutamyl transpeptidase) from the gastric (fundus, body and antrum) and duodenal mucosa [i.e. first (D1) and second (D2) part of the duodenum] were determined in 6 control, 6 protein-energy malnourished (PEM) and 6 rehabilitated young rhesus monkeys. There was a significant increase in the activity of the lactase enzyme in the antrum, and D1 and D2 portions of the duodenum of PEM monkeys, while the activity of all other enzymes was significantly increased in the D1 and D2 portions only. The increase in the activity of the above-mentioned enzymes became normal upon rehabilitation. There was no change in the enzyme activities of the gastric mucosa in mild-to-moderate PEM states. This study demonstrates that even mild-to-moderate malnutrition states affect the activity of enzymes in the gastric and duodenal mucosa. Enzyme activity recovers on rehabilitation.
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PMID:Effect of malnutrition on the digestive enzymes of the upper gastrointestinal tract of young rhesus monkeys. 1297 10

The aim of the present study was to investigate the effect of mild-to-moderate protein-energy malnutrition (PEM) and rehabilitation on the digestive enzymes of the large bowel in young rhesus monkeys. The presence of these enzymes has already been reported in the large bowel by many authors. The activities of the digestive enzymes, i.e. lactase, sucrase, maltase, trehalase, glucoamylase, leucine aminopeptidase, alkaline phosphatase and gamma-glutamyl transpeptidase, from different parts of the large bowel were determined in 6 controls, 6 PEM and 6 rehabilitated young rhesus monkeys. These monkeys had been used to study the effect of malnutrition on the small intestine and the results have already been published. There was a significant decrease in the sucrase in the ascending colon (p < 0.05); maltase in all the parts of the large bowel (p < 0.05); and glucoamylase activities (p < 0.05) in the caecum segment of the large bowel in the PEM group. The activity of other enzymes, i.e. lactase, trehalase, alkaline phosphatase, gamma-glutamyl transpeptidase and leucine aminopeptidase, was unaffected in the PEM group. The changes in the enzyme activities recovered on rehabilitation of 21 weeks. The result of this study suggest that even mild-to-moderate malnutrition affects the enzyme activity of the large bowel, which recovers on rehabilitation.
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PMID:Effects of malnutrition on the digestive enzymes of the large bowel of young rhesus monkeys. 1516 29


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