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:3.2.1.20 (alpha-glucosidase)
4,237 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The development of brush-border enzymes and the possible regulatory role of cortisol were investigated in the small intestine of the fetal and neonatal pig. With the sows under pentobarbitone anesthesia, osmotic minipumps containing either saline or cortisol were inserted s.c. into 25 fetuses from 10 pregnant sows (82-96 d gestation). Six d later, the infused fetuses were removed by cesarean section and samples of the proximal, middle, and distal intestine taken for analysis. Samples were also obtained from 48 piglets that did not undergo an operation (controls) and that were removed at intervals from 82 d gestation until term (114 +/- 2 d). In the proximal and middle intestine, the mean levels of lactase-phlorizin hydrolase (EC 3.2.1.23-62), maltaseglucoamylase (EC 3.2.1.20), aminopeptidase N (EC 3.4.11.2), and aminopeptidase A (EC 3.4.11.7) increased during the last 10-15 d before term, correlated positively with log10 plasma cortisol values, and were higher in cortisol-infused than in saline-infused fetuses (p < 0.05). Activity of sucrase-isomaltase (EC 3.2.1.48-10) was low in fetal pigs, and this enzyme and dipeptidyl peptidase IV (EC 3.4.14.5) were not significantly affected by fetal age or exogenous cortisol. Maltase (EC 3.2.1.48-10 and EC 3.2.1.20) activity was significantly decreased in the middle and distal intestine of cortisol-infused fetuses. The results suggest that the prepartum rise in endogenous cortisol secretion stimulates the prenatal expression of certain brush-border enzymes in the pig small intestine at this critical time. However, the effects of cortisol on the developing intestine were highly idiosyncratic for particular enzymes and intestinal regions.
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PMID:The prenatal development and glucocorticoid control of brush-border hydrolases in the pig small intestine. 773 59

Premature infants are susceptible to intestinal ischemia during the newborn period when their intestinal tracts are functionally and structurally immature. Studies have shown that exogenous glucocorticoids hasten intestinal maturation. We investigated the effects of hydrocortisone on platelet activating factor (PAF)-induced intestinal ischemia in the neonatal rat. On Postnatal Days 7-11, Sprague-Dawley rats were given intraperitoneal (ip) injections of either saline (SAL) or hydrocortisone (HC; 50 mg/kg total). On Day 12, rats were injected with either PAF (2 micrograms/kg) or an equal volume of saline. After 2 hr the rats were sacrificed and sections were taken for histology. The remaining intestine was analyzed for maltase, lactase, myeloperoxidase (MPO), and xanthine oxidase (XO). Experimental groups were as follows: SAL (N = 8), received saline only; SAL+PAF (N = 8), received saline plus PAF; HC (N = 3), received hydrocortisone+saline; and HC+PAF (N = 5), received hydrocortisone plus PAF. XO was significantly decreased (P < 0.001) in the hydrocortisone-treated groups (HC + SAL = 16.36 +/- 18.42 units/g protein, HC + PAF = 17.33 +/- 9.06 units/g protein) vs the controls (SAL only = 108.90 +/- 20.24 units g/protein, SAL + PAF = 145.77 21.28 units/g protein). MPO was not significantly elevated in SAL + PAF (4.60 +/- 0.95 units/g protein) vs HC + PAF (2.18 +/- 0.80 units/g protein) in this study. Maltase was significantly elevated (P < 0.001) in the HC + PAF (241.46 +/- 40.6 mole/min/g protein) and HC + SAL (152.78 +/- 16.35 mole/min/g protein) vs saline only (28.35 +/- 5.77 mole/min/g protein and SAL + PAF (37.29 +/- 8.70 mole/min/g protein. Animals (7/8) in the SAL + PAF group developed ischemia by inspection and histologic exam.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Intestinal ischemia in the newborn: the role of intestinal maturation. 824 92

Two isoenzymes of maltase (EC 3.2.1.20) were purified to homogeneity from Candida albicans. Isoenzymes I and II were found to have apparent molecular masses of 63 and 66 kDa on SDS/PAGE with isoelectric points of 5.0 and 4.6 respectively. Both isoenzymes resembled each other in similar N-terminal sequence, specificity for the alpha(1-->4) glycosidic linkage and immune cross-reactivity on Western blots using a maltase II antigen-purified rabbit antibody. Maltase was induced by growth on sucrose whereas beta-fructofuranosidase activity could not be detected under similar conditions. Maltase I and II were shown to be unglycosylated enzymes by neutral sugar assay, and more than 90% of alpha-glucosidase activity was recoverable from spheroplasts. These data, in combination with other results from this laboratory [Geber, Williamson, Rex, Sweeney and Bennett (1992) J. Bacteriol. 174, 6992-6996] showing lack of a plausible leader sequence in genomic or mRNA transcripts, suggest an intracellular localization of the enzyme. To establish further the mechanism of sucrose assimilation by maltase, the existence of a sucrose-inducible H+/sucrose syn-transporter was demonstrated by (1) the kinetics of sucrose-induced [14C]sucrose uptake, (2) recovery of intact [14C]sucrose from ground cells by t.l.c. and (3) transport of 0.83 mol of H+/mol of [14C]sucrose. In total, the above is consistent with a mechanism whereby sucrose is transported into C. albicans to be hydrolysed by an intracellular maltase.
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PMID:Role of maltase in the utilization of sucrose by Candida albicans. 848 4

Brush border enzymatic activities (maltase, lactase and sucrase) have been determined in the ileal mucosa of rats subjected to a 30% ethanol ingestion for 3 and 5 months. The data were compared with the results obtained with control rats. Mucosal protein content after 3 months of ethanol treatment was similar to that of control rats. Maltase, lactase and sucrase specific activities in ileal mucosa were significantly decreased in ethanol-fed animals as compared to control rats. After 5 months of ethanol consumption, the protein content was decreased in ethanol-fed rats. However, no differences were found between specific activities of maltase, lactase and sucrase of ethanol-fed with respect to control rats. It is suggested that prolonged exposure of rats to ethanol results in adaptive responses to the effects of shorter periods of exposure on intestinal mucosal function.
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PMID:Changes in the ileal disaccharidase activities in rats after long-term ethanol feeding. 867 76

In three experiments broiler chickens were inoculated with sporulated Eimeria acervulina oocysts at 18 d of age. Feed intake, body-weight gain, brush-border enzyme activities, fat digestion, protein digestion and protein retention were measured. Body-weight gain was reduced during the acute phase of the infection and increased during the recovery phase of the infection. Feed intake was decreased on day 4 and day 5 postinfection (PI) and increased from day 7 to day 11 PI. Maltase (EC 3.2.1.20) and sucrase (EC 3.2.1.48) activities were decreased on day 5 PI in all intestinal segments. In Expts 2 and 3, however, maltase activity was increased in the ileum. Fat digestion was decreased from day 2 to day 11 PI. N digestion and retention were decreased from day 2 to day 11 PI.
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PMID:Interaction between nutrition and Eimeria acervulina infection in broiler chickens: development of an experimental infection model. 877 31

Non-physiological amounts of oral polyamines have been reported to induce precocious gut maturation in rat pups. The aim of the present study was to investigate organ distribution and metabolic fate of orally administered stable-isotopically labelled polyamines in rat pups. Pups received tetradeuterium-labelled putrescine (Pu-d4; 3 mumol), spermidine (Sd-d4; 5 mumol), spermine (Sp-d4; 3 mumol), or physiological saline twice daily on postnatal days 7-10 or 12-15. They were killed on days 10 and 15. We determined activities of ileal lactase (EC 3.2.1.23), maltase (EC 3.2.1.20), sucrase (EC 3.2.1.48) and diamine oxidase (EC 1.4.3.6) and established villus and crypt lengths. Polyamines and their labelling percentages in organs were determined by GC and mass fragmentography. Treatments did not affect growth rate, but caused lower weights of liver, kidneys and heart. Maltase activity increased, lactase decreased, whereas sucrase and diamine oxidase did not change. Villus and crypt lengths increased. Organ polyamine pools were labelled to different extents. Irrespective of the orally administered polyamine, all organs contained Pu-d4, SD-d4 and Sp-d4. Administered Pu-d4 and Sd-d4 were recovered mainly as Sd-d4, whereas Sp-d4 was recovered as Sp-d4 and Sd-d4. Total polyamines in a caecum, colon and erythrocytes increased, but increases were only to a minor extent with regard to labelled polyamines. Our data confirm precocious gut maturation by exogenous polyamines. Putrescine appears to be limiting factor. The exogenous polyamines were distributed among all investigated organs. They are not only used for the synthesis of higher polyamines, but also retroconverted to their precursors. Changes in erythrocyte polyamine contents suggest precocious stimulation of erythropoiesis.
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PMID:Oral administration of deuterium-labelled polyamines to sucking rat pups: luminal uptake, metabolic fate and effects on gastrointestinal maturation. 938 89

Responses to stunting syndrome (SS) infective material obtained from affected broilers and administered per os were monitored for 3 wk in a fast-growing commercial broiler population, in slow-growing Leghorn chicks, and in turkey poults. At 2 and 3 wk, the size of the gastrointestinal tract (GIT) segments, the pH of the GIT contents, and the activities of digestive enzymes in the intestinal contents and of disaccharidases on the jejunum mucosae were determined. Inoculation affected the genetic stocks differently. In broiler chicks, growth and feed utilization were markedly reduced. In contrast, inoculation of Leghorns was accompanied by improved feed intake and growth rate. Performance of poults was affected only slightly, albeit significantly. The effect of inoculation on the pH of crop and intestinal contents in Leghorn chicks was opposite to that found in broiler chicks, i.e., a significant increase in the crop and small intestinal pH in the former vs a significant decrease in inoculated broilers. Although inoculation of the broiler chicks did not affect the pH in the proventriculus, in Leghorn chicks it was reduced by 25%. In poults, inoculation did not significantly affect GIT contents pH. The GIT segments were markedly enlarged in broiler chicks, whereas in Leghorn chicks the opposite trend was observed; namely, intestinal segment weights were significantly reduced. In poults, inoculation caused a reduction in the intestinal segments and gizzard weight at 3 wk. During this same period, the liver and pancreas relative weights were dramatically increased in broiler chicks. A higher relative heart weight at 2 wk was observed in broilers and poults; this trend persisted to Week 3 in poults but not in broiler chicks. In broiler chicks, a nonsignificant reduction was observed for all enzymes assayed at 3 wk and for chymotrypsin at 2 wk. In Leghorn chicks, inoculation was accompanied by a marked and significant increase in the activity of chymotrypsin during both periods. In poults, inoculation caused a marked increase in the activities of amylase during Week 2 and 3, and trypsin at 3 wk. Maltase and saccharase activities in the jejunum of broiler chicks were slightly depressed a t 2 and 3 wk, the depression being significant at 2 wk for maltase and at 3 wk for saccharase. In the Leghorn chicks, inoculation caused a twofold increase in the activities of both enzymes. As in Leghorns, inoculation of poults with SS infective material caused a marked increase in the activities of the disaccharidases. The different responses to SS inoculation in the different genetic stocks are discussed.
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PMID:Stunting syndrome in broilers: effect of stunting syndrome inoculum obtained from stunting syndrome affected broilers, on broilers, leghorns and turkey poults. 949 86

The adaptive modulation hypothesis posits that the expression of digestive proteins should be modulated in response to intake of their respective substrates. A corollary of this hypothesis suggests that dietary flexibility and digestive plasticity should be correlated. We examined these two hypotheses in two granivorous Chilean birds (Zonotrichia capensis and Diuca diuca) that differ in dietary breadth. D. diuca is a strict granivore, whereas Z. capensis also eats insects. In field-caught birds, the activity of the intestinal dipeptidase aminopeptidase-N was positively correlated with intake of insects in Z. capensis but not in D. diuca. This is the first field documentation of modulation of intestinal enzymes by diet in birds. Intestinal maltase and sucrase activities were not correlated with seed (vs. insect) intake in either species. In the laboratory, captive birds of both species exhibited similar modulation of membrane-bound intestinal hydrolases when fed on synthetic diets of contrasting carbohydrate and protein composition. Maltase, sucrase, and aminopeptidase-N activities were significantly higher in birds fed on the carbohydrate-free than those on the carbohydrate-containing diet. Activities of the three enzymes were positively correlated. Therefore, this increase probably resulted from nonspecific increases of all enzymes resulting from intake of the carbohydrate-free diet. Principal components analysis separating the effect of diet on specific and on nonspecific modulation revealed that diet had a strong effect on nonspecific activity of intestinal enzymes in both Z. capensis and D. diuca. Diet also significantly affected aminopeptidase-N activities when the effect of diet on nonspecific modulation was removed. Birds fed on the carbohydrate-free, high-protein diet had significantly higher specific aminopeptidase-N activities than those fed on the carbohydrate-containing diet. Our results cast doubts on the notion that dietary flexibility and the plasticity of the gut's enzymes are necessarily correlated and on the general validity of the adaptive modulation hypothesis.
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PMID:Dietary flexibility and intestinal plasticity in birds: a field and laboratory study. 954 55

The existence of disaccharidases and an enzyme that hydrolyzes maltitol were investigated in the large intestine of rats. In addition, the properties of disaccharidases were studied in the cecum and colon with hyperplasia induced by the ingestion of nondigestible carbohydrates such as maltitol and glucomannan. Maltase activity was detected in the cecal and colonic mucosa of rats fed a regular diet, although it was a very low level as compared with that in the small intestinal mucosa. Maltitol hydrolysis was notably lower in the cecum and colon than in the small intestine. The Km of maltose was 5.56 mM in the small intestine and 5.59 mM in the cecum, while that in the colon was 2.56 mM. The Vmax of maltose was at very low levels in the cecum (0.38 mumol/mg protein/h) and colon (0.37 mumol/mg protein/h) in comparison with that in the small intestine (30.3 mumol/mg protein/h). With regard to the maltitol hydrolyzing enzyme, Km and Vmax were 2.00 mM and 2.51 mumol/mg protein/h in the small intestine, respectively. Km and Vmax in the cecum and colon could not be measured because the level was too low. The tissue weights of the cecum and colon increased significantly in both the maltitol (p < 0.01, p < 0.05) and glucomannan (p < 0.01, p < 0.05) groups in comparison with that of the control group. The specific activity of maltase decreased significantly in the small intestine of the maltitol (p < 0.05) and glucomannan (p < 0.01) groups. However, maltase activity in the cecum and colon was not lowered by maltitol ingestion, although it decreased significantly in the cecum of the glucomannan group (p < 0.01). Sucrase activity in the small intestine and cecum was decreased significantly by maltitol (p < 0.05, p < 0.01) or glucomannan (p < 0.01, p < 0.01) ingestion, whereas it was not decreased in the colon. Maltitol hydrolyzing activity did not decrease significantly in the small intestine of the maltitol group, although that in the cecum and colon was not measured exactly by the methods used here. These results demonstrate that disaccharidases exist in the cecal and colonic mucosa of rat, and that they are not induced even in the tissue with hyperplasia, which is caused by maltitol ingestion.
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PMID:Disaccharidase activity in rat cecum and colon with hyperplasia induced by maltitol or glucomannan. 959 Dec 35

An alpha-glucosidase cDNA clone derived from barley aleurone tissue was expressed in Pichia pastoris and Escherichia coli. The gene was fused with the N-terminal region of the Saccharomyces cerevisiae alpha-factor secretory peptide and placed under control of the Pichia AOX1 promoter in the vector pPIC9. Enzymatically active, recombinant alpha-glucosidase was synthesized and secreted from the yeast upon induction with methanol. The enzyme hydrolyzed maltose > trehalose > nigerose > isomaltose. Maltase activity occurred over the pH range 3.5-6.3 with an optimum at pH 4.3, classifying the enzyme as an acid alpha-glucosidase. The enzyme had a Km of 1.88 mM and Vmax of 0.054 micromol/min on maltose. The recombinant alpha-glucosidase expressed in E. coli was used to generate polyclonal antibodies. The antibodies detected 101 and 95 kDa forms of barley alpha-glucosidase early in seed germination. Their levels declined sharply later in germination, as an 81 kDa alpha-glucosidase became prominent. Synthesis of these proteins also occurred in isolated aleurones after treatment with gibberellin, and this was accompanied by a 14-fold increase in alpha-glucosidase enzyme activity.
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PMID:Expression of enzymatically active, recombinant barley alpha-glucosidase in yeast and immunological detection of alpha-glucosidase from seed tissue. 974 46


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