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)

Daily urinary excretion of acid maltase (12.78 +/- 2.10 units/24 hr/mg of creatinine, in 11 normal adults) was significantly decreased in ten patients with late-onset acid maltase deficiency (1.33 +/- 0.16 units/24 hr; P less than .001) and 11 heterozygotes (3.27 +/- 0.62 units/24 hr; P less than .001). Maximal inhibition of urinary acid maltase activity by antibodies against human placental enzyme was 53% in controls, 30% in heterozygotes, and virtually absent in patients. Investigation of pH curves and enzyme inhibition by antibodies confirmed the presence in the kidney of an immunologically distinct "extra" maltase enzyme active at acid pH. Whether acid maltase in normal urine originates in the kidney or cells of the lower urinary tract, the enzyme defect seems to be expressed in these cells in late-onset acid maltase deficiency.
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PMID:Late-onset acid maltase deficiency. Detection of patients and heterozygotes by urinary enzyme assay. 0 23

The mechanism of starch degradation by the fungus Trichoderma viride was studied in strain CBS 354.44, which utilizes glucose, starch and dextrins but is unable to assimilate maltose. It was shown that the amylolytic enzyme system is completely extracellular, equally well induced by starch, amylose or amylopectin and that it consists mainly of enzymes of the glucoamylase type which yield glucose as the main product of starch hydrolysis. Small amounts of alpha-amylase are produced also. The enzymes produced in starch cultures degrade starch, amylose and amylopectin equally well. Enzyme synthesis in starch media takes place to a considerable extent after exhaustion of the carbon source when maximum growth has been attained. Low-molecular dextrins are degraded by extracellular enzymes of the glucoamylase type. These enzymes are produced in media containing starch or dextrins. Maltotriose is consumed for only one third leaving maltose in the culture filtrate. Maltose is hardly attacked and hardly induces any amylolytic enzyme activity. No stable alpha-glucosidase appears to be produced.
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PMID:Starch degradation by the mould Trichoderma viride. I. The mechanism of starch degradation. 1 Aug 32

Production of glucoamylase and glycosyltransferase by Endomyces fibuliger was found to depend on sources of carbon and nitrogen nutrition. Starch at a concentration above 0.5% in the medium stimulated biosynthesis of glycosyltransferase but inhibited production of glucoamylase by End. fibuliger 20-9. The rate of growth of the micro-organism increased by a factor of 3.3 with an increase of starch concentration from 0.5 to 6%. Synthesis of glycosyltransferase was repressed by glucose, lactose, sucrose and maltose. Synthesis of glucoamylase was repressed by lactose, sorbose and galactose. Synthesis of glycosyltransferase was stimulated by xylose, sorbose and galactose. Production of glucoamylase was stimulated by xylose and arabinose. Growth of the culture and synthesis of glucoamylase and maltase in the cultural broth were stimulated by an increase in the concentration of maize extract. Biosynthesis of glucoamylase and glycosyltransferase was stimulated by NH4H2PO4.
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PMID:[Effect of growth medium composition of glucoamylase and glycosyltransferase activity of Endomyces fibuliger]. 1 49

An assay for alpha-1,4-glucosidase (acid maltase) activity which is deficient in Pompe's disease is described. The assay can be used to measure the enzyme in cultured skin fibroblasts, cultured amniotic cells and peripheral blood leucocytes. [U-14 C]Maltose is used as the substrate in a total assay volume of 8 microliter. The product, [U-14C]glucose, is separated from the substrate by cellulose thin-layer chromatography. The procedure permits replicate assays from 400 microliter whole blood and from amniotic cells in primary culture. Discrimination of the heterozygous Pompe state appears to be facilitated.
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PMID:A micro-radiochemical assay for alpha-1,4-glucosidase and its use in the assessment of type II glycogenosis (Pompe's disease). 1 94

Pure rat intestinal maltase/glucoamylase was partially inactivated in 1% sodium dodecyl sulphage by heating at 40--70 degree C for 5 min at pH 7.5, or by lowering the pH to 5.4--6.6 at 24 degree C. When partially active preparations were electrophoresed in the presence of sodium dodecyl sulphate, a complicated protein band pattern of incompletely dissociated fragments of the enzyme was observed. Complete dissociation of the enzyme in sodium dodecyl sulphate, induced by boiling or by pH values below 5.4, was accompanied by total loss of enzyme activity and simplification of the protein pattern to five major species. Although the original enzyme band was absent from some partially dissociated preparations, enzyme activity was present and was associated with several transient protein bands on the gels. Maltase and alpha-glucosidase activities were detected in these bands, but glucoamylase activity was absent.
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PMID:Enzyme activity in partly dissociated fragments of rat intestinal maltase/glucoamylase. 3 55

At various postnatal stages, intestinal epithelial cells were isolated sequentially from villus tip to crypt base by successive EDTA treatments. According to the localization of marker enzymic activities, isolated cells were pooled into three cell compartments: villus (V), lower villus and upper crypt (VC) and crypt (C). Purified brush-border-membrane proteins were separated by 7.5%-polyacrylamide-gel electrophoresis in the presence of sodium dodecyl sulphate. Enzymic activities could be assigned to some protein bands: maltase/glucoamylase (protein band 3), sucrase-isomaltase (protein bands 3 and 6), lactase (protein band 5) and alkaline phosphatase (region of protein bands 8 and 9). The findings suggest the following. (1) Sucrase-isomaltase activities appeared in compartment C at 17 days with a simultaneous increase of the pre-existing protein band 3 and appearance of a well-defined protein band in position 6; the enzymic complex remained still present in the crypt cells until adulthood. From the day 21 onwards, sucrase-isomaltase was detected in compartments VC and V. (2) Lactase was only present in the three cell compartments until day 21; at this developmental stage its activity completely disappeared from compartment C, in spite of the persistence of a weak protein band. (3) Alkaline phosphatase activity could be detected as a single peak corresponding to protein band 9 in all three cell compartments until day 21; thereafter it was replaced by two peaks of activity showing a less precise correlation with the well-defined protein bands 8 and 9. In the crypt cells of the adult rat, however, the preweaning situation, which was regularly observed, is an unexpected phenomenon. (4) Maltase and glucoamylase did not display any marked qualitative or quantitative modifications either along the villus-crypt axis or during the period of postnatal development studied. Evidence is given from the present data that each brush-border enzyme investigated has a specific developmental pattern.
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PMID:Developmental pattern of rat intestinal brush-border enzymic proteins along the villus--crypt axis. 10 86

Some molecular properties of the purified neutral alpha-glucosidase from human kidney were studied. The enzyme is a glycoprotein with high molecular weight (315000-352000 according to the method used). Its sedimentation coefficient is 12.9S. It exhibits at least three peaks of activity in isoelectric focusing experiments. This heterogeneity appears to be related to sialic acid residues from the carbohydrate moiety. An anti-human renal alpha-glucosidase antiserum was raised from rabbit. The antiserum effect on human intestinal maltases was studied in immunodiffusion experiments. An identity pattern was observed between renal neutral alpha-glucosidase and intestinal glucoamylase. No precipitation occurred with intestinal sucrase. Renal neutral alpha-glucosidase and intestinal glucoamylase were both completely precipitated by the antiserum, their maltase activity being only slightly inhibited in the antigen-antibody complex. From their molecular and immunological properties a large homology appears between human renal alpha-glucosidase and intestinal glycoamylase.
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PMID:Neutral alpha-glucosidase from human kidney. Molecular and immunological properties. Relationship with intestinal glucoamylase. 11 52

Tissues from the cerebral cortex, liver and myocardium of a patient with Lafora disease were obtained at autopsy and were studied biochemically. 1. Glucose content in the myocardium and liver was almost nil while that in the controls was 0.66 mg/g wet weight in the former and 8.80 mg/g wet weight in the latter. Glycogen content in the cerebral cortex and myocardium was about 10 and 3 times more than in controls. 2. Polyglucosan extracted from the cerebral cortex, liver and myocardium had a longer exterior glucose chain than that in the liver of the control but a normal, alpha or beta 1,4-glucosidic linkage was observed. 3. The activities of glucose-6-phosphatase and amylo-1,6-glucosidase in the cerebral cortex, liver and myocardium were well preserved. The activities of acid maltase in the three organs mentioned above and of neutral maltase in the myocardium were elevated twice and one and half times more than the control. Phosphorylase levels in the myocardium were extremely small, while in the cerebral cortex and liver normal activities were observed. In light of these findings, glycogen metabolism in Lafora disease is discussed.
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PMID:Biochemical studies on tissues from a patient with Lafora disease. 17 19

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

A brush-border-specific antiserum was raised in rabbits, with Triton X-100-solubilized brush border proteins from pig intestine being used as antigens. The antiserum was used in immunoelectrophoretic studies of brush border proteins solubilized with Triton X-100. Five immunoprecipitates were obtained which corresponded to microsomal aminopeptidase (EC 3.4.11.2), asparate aminopeptidase (EC 3.4.11.7), lactase (beta-galactosidase, EC 3.2.1.23), maltase (exo-1,4-alpha-glucosidase, EC 3.2.1.3) and sucrase-isomaltase (sucrose alpha-glucohydrolase, EC 3.2.1.48). A faint immunoprecipitate was also found for the glycylprolyl dipeptidyl peptidase (EC 3.4.14.-). The brush border proteins were solubilized on a large scale from a brush border membrane preparation by the use of Triton X-100; the peptidases obtained were homogeneous in size and had hydrophobic properties. By chromatography on columns of concanavalin A-Sepharose, hydroxyapatite, Ultrogel AcA 34, DEAE-cellulose and immunosorbent, gamma-glutamyl transpeptidase (gamma-glutamyl transferase, EC 2.3.2.2) and microsomal aminopeptidase were each isolated in separate fractions. Glycylprolyl dipeptidyl peptidase and asparate aminopeptidase were obtained in another fraction. Immunoelectrophoretic, inhibitor and chromatographic studies showed that the intestinal brush border peptidases are similar to the corresponding particulate peptidases obtained from other organs.
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PMID:Intestinal brush border peptidases. 24 83


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