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)

1. The rates of accumulation (enzyme units/h per 10(8) cells) of a number of glycosidase activities were studied in Dictyostelium discoideum cells during the growth and differentiation phases of this organism's life cycle. 2. The rates of accumulation of the enzymes beta-N-acetylglucosaminidase, alpha-glucosidase and beta-galactosidase remain unchanged during the growth and early differentiation phases. 3. The considerable changes in specific activity of the enzymes which occur in the early differentiation phase are due to the massive loss of total cellular protein which occurs at this time. 4. Significant alterations can occur in the rates of accumulation of alpha-mannosidase during both the growth and differentiation phases, and since, on the onset of differentiation, beta-glucosidase activity is excreted and degraded, the rate of accumulation of this enzyme differs in the growth and differentiation phases. 5. The characteristic rates of accumulation of all these glycosidases change markedly with changes in the growth conditions of the myxamoebae, and thus these rates of synthesis must be regulated independently; however, addition of cyclic AMP to the growth medium has no effect on them.
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PMID:Rates of accumulation of glycosidase activities during growth and differentiation of Dictyostelium discoideum. 117 88

Maltase, sucrase, and lactase were measured at pH 4 and pH 6 in normal and intestinalized gastric mucosa. In the normal mucosa the low activities of maltase and lactase seemed to be entirely due to lysosomal enzymes with acid pH-optimum. In intestinal metaplasia, brush border maltase and sucrase, but not lactase, appeared. On the other hand, there was a significant increase in lysosomal lactase (beta-galactosidase) activity.
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PMID:Disaccharidase activities in intestinal metaplasia - contribution of lysosomal brush border enzymes. 117 60

Studies have been carried out on activities of lysosomal beta-N-acetylhexosaminidase (hex), beta-galactosidase (beta-gal), alpha-glucosidase (alpha-glu), and acid phosphatase (AP) in serum and urine from patients with juvenile diabetes and matched controls. There is a large increase in blood and urinary hex activity (the former presenting three distinct patterns of abnormality), a moderate increase in urinary beta-gal, and a small increase in urinary alpha-glu activity, but no elevation of blood or urinary AP in the diabetics. Urinary alpha-glu activity in the diabetics shows striking inhibition by glucose, and this may reflect a similar phenomenon in vivo. Although glycohydrolase activities are elevated in patients with no detectable microangiopathy, more striking changes may be observed in patients with severe small-vessel disease. These alterations may be associated with increased glycoprotein catabolism in the diabetic, an area in need of further studies in the human and experimental diabetic animal.
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PMID:Altered lysosomal glycohydrolase activities in juvenile diabetes mellitus. 126 40

Microbioassays using bacteria or enzymes are increasingly applied to measure chemical toxicity in the environment. Attractive features of these assays may include low cost, rapid response to toxicants, high sample throughput, modest laboratory equipment and space requirements, low sample volume, portability, and reproducible responses. Enzymatic tests rely on measurement of either enzyme activity or enzyme biosynthesis. Dehydrogenases are the enzymes most used in toxicity testing. Assay of dehydrogenase activity is conveniently carried out using oxidoreduction dyes such as tetrazolium salts. Other enzyme activity tests utilize ATPases, esterases, phosphatases, urease, luciferase, beta-galactosidase, protease, amylase, or beta-glucosidase. Recently, the inhibition of enzyme (beta-galactosidase, tryptophanase, alpha-glucosidase) biosynthesis has been explored as a basis for toxicity testing. Enzyme biosynthesis was found to be generally more sensitive to organic chemicals than enzyme activity. Bacterial toxicity tests are based on bioluminescence, motility, growth, viability, ATP, oxygen uptake, nitrification, or heat production. An important aspect of bacterial tests is the permeability of cells to environmental toxicants, particularly organic chemicals of hydrophobic nature. Physical, chemical, and genetic alterations of the outer membrane of E. coli have been found to affect test sensitivity to organic toxicants. Several microbioassays are now commercially available. The names of the assays and their basis are: Microtox (bioluminescence), Polytox (respiration), ECHA Biocide Monitor (dehydrogenase activity), Toxi-Chromotest (enzyme biosynthesis), and MetPAD (enzyme activity). An important feature common to these tests is the provision of standardized cultures of bacteria in freeze-dried form. Two of the more recent applications of microbioassays are in sediment toxicity testing and toxicity reduction evaluation. Sediment pore water may be assayed directly or solvents may be used to extract the toxicants. Some of the solvents used for extraction of organic chemicals are themselves toxic to bacteria (e.g., dichloromethane), requiring exchange with a less toxic solvent (e.g., ethanol, methanol, DMSO). A modification of the Microtox test allows direct assay of solid-phase samples such as sediments. The toxicity reduction evaluation (TRE) must be carried out at wastewater treatment plants whose effluents fail toxicity standards. The TREs require numerous and repeated toxicity assays, thus favoring application of microbioassays. Presently, no single microbioassay can detect all categories of environmental toxicants with equal sensitivity. Therefore, a battery of tests approach is recommended. The differential sensitivity of alternative tests may, in fact, be exploited. Further research is needed to construct strains of genetically engineered microorganisms or isolate microorganisms or enzymes that respond to specific classes of toxicants. These can be combined into batteries appropriate for different environments or test objectives.
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PMID:Bacterial and enzymatic bioassays for toxicity testing in the environment. 150 75

The serum concentrations of FSH, LH, prolactin, testosterone, and estradiol and the enzymatic activities of hyaluronidase, glucosidases (alpha-glucosidase, beta-glucosidase, alpha-mannosidase, N-acetyl-beta-D-glucosaminidase, beta-glucuronidase, and beta-galactosidase), lactate dehydrogenase and its isoenzymes (LDH1, LDH2, LDH3, LDH-X, LDH4), and total proteins were measured in the semen of 69 subjects (8 normozoospermic controls, 7 secretory, and 54 excretory azoospermic subjects). FSH levels rose with the deterioration in spermatogenesis and served to differentiate the secretory from the excretory azoospermias. The only source of hyaluronidase and LDH-X in the ejaculate is the spermatozoa. alpha-Glucosidase activity essentially originates in the epididymis. The seminal determination of alpha-glucosidase and, to a lesser extent, alpha-mannosidase and N-acetyl-beta-D-glucosaminidase helps rapidly, sensitivity, reliably, and noninvasively to differentiate secretory azoospermias (with higher enzymatic activity) from the excretory type (less enzymatic activity) and may be of use in identifying with a certain degree of reliability the site of obstruction in the male genital tract.
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PMID:Enzyme and hormonal markers in the differential diagnosis of human azoospermia. 153 Mar 67

A study was carried out to examine whether the responsiveness of small intestinal epithelial cells to dietary carbohydrate varied during the daily 24 h cycle. The effect of sucrose on disaccharidase activities was compared during a period of decreasing disaccharidase activities, i.e. between 22.00 and 10.00 hours, and increasing disaccharidase activities, i.e. between 10.00 and 22.00 hours, in the jejunum of 7-week-old-rats. Rats were fed on a low-starch, high-fat diet (Lst; starch 5 and fat 73% of gross energy), or a high-starch, low-fat diet (Hst; starch 70 and fat 7% of gross energy). Both dietary groups exhibited typical diurnal variations in jejunal sucrase (EC 3.2.1.48), maltase (EC 3.2.1.20) and lactase (EC 3.2.1.23) activities, exhibiting a peak around 22.00 hours and a trough at approximately 10.00 hours. When rats were fed on diet Lst for 7 d and then force-fed on an isoenergetic sucrose diet (S; sucrose 40 and fat 37% of gross energy) for 6 or 12 h they exhibited increased sucrase, maltase and lactase activities compared with rats fed on diet Lst. The absolute increase in disaccharidase activities was similar regardless of the time diet S was given or whether rats were killed at 10.00 hours or at 22.00 hours. Analyses of sucrase and lactase activities along the villus-crypt columns showed that the distribution of cell cohorts that responded to diet S was not influenced by the time of introduction of diet S. These findings suggest that small intestinal epithelial cells possess the ability to respond to dietary carbohydrate throughout the daily 24 h cycle.
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PMID:Dietary-induced increases of disaccharidase activities in rat jejunum. 159 99

Specific glycosidase activities were determined in samples of gingival crevicular fluid (GCF) collected from eight predetermined sites in two groups, each of 20 adult patients, with either gingivitis or periodontitis. The total activities (as units of enzyme activity per sample) of alpha-L-fucosidase, sialidase, beta-N-acetylglucosaminidase, beta-galactosidase, beta-glucosidase and alpha-glucosidase were significantly greater in the periodontitis group. In contrast, the total beta-mannosidase and hexosaminidase A activities were significantly greater in the gingivitis group, while there was no significant difference in the total alpha-mannosidase activity between the groups. Only the specific activities (as units of enzyme activity per min per microliter of GCF) of beta-mannosidase and hexosaminidase A were significantly different between the groups being greater in the gingivitis group. When used to predict the clinical status of individual periodontal sites, the total enzyme activities had specificity and sensitivity values of 91.9 and 61.3%, respectively. Measurement of glycosidase activities might thus have a role in monitoring the efficacy of periodontal treatment or in predicting future periodontal disease but this will require further investigation.
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PMID:Glycosidase activities in gingival crevicular fluid in subjects with adult periodontitis or gingivitis. 161 Mar 3

1. beta-Glucosidase, alpha-glucosidase, beta-galactosidase and alpha-mannosidase were measured in epidermis, palatal and buccal epithelium of the pig (Sus scrofa). 2. All three epithelia contained similar alpha-mannosidase activity (1.7-3.2 nmol mg tissue-1 hr-1 at pH 4), and none contained significant alpha-glucosidase. 3. Specific activity of beta-glucosidase was high (9-13 nmol mg tissue-1 hr-1 at pH 4) in epidermis and palate, but activity was low (less than 2 nmol mg tissue-1 hr-1) in buccal epithelium. 4. Only epidermis contained a high level of beta-galactosidase (5.8 nmol mg tissue-1 hr-1). 5. Differences in glycosidase profiles may underlie differences in permeability barrier properties in these epithelia.
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PMID:Comparison of glycosidase activities in epidermis, palatal epithelium and buccal epithelium. 175 16

During liver transplantation in the pig, the plasma activities of beta-galactosidase, beta-glucuronidase and beta-glucosidase were elevated as early as 15 min after establishing the hepatic circulation. The enzyme activities peaked at 3 h and returned to the initial level within 2-3 days. However, such substantial alterations were not observed in other enzymes, alpha-mannosidase and alpha-glucosidase. Similar reactions to those of the first three enzymes were found in aspartate aminotransferase and lactate dehydrogenase but with later peaks and slower eliminations. In light of the current study, the serial estimation of acid hydrolases may be useful to discover the extent of tissue injury and also to evaluate the effectiveness of various organ-preservation methods.
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PMID:Plasma lysosomal enzymes after liver transplantation in the pig. 181 48

High-pressure liquid chromatography and microcalorimetry have been used to study the thermodynamics of the hydrolysis reactions of a series of disaccharides. The enzymes used to bring about the hydrolyses were: beta-galactosidase for lactulose and 3-o-beta-D-galactopyranosyl-D-arabinose; beta-glucosidase for alpha-D-melibiose; beta-amylase for D-trehalose; isomaltase for palatinose; and alpha-glucosidase for D-turanose. The buffer used was sodium acetate (0.02-0.10 M and pH 4.44-5.65). For the following processes at 298.15 K: lactulose(aq) + H2O(liq) = D-galactose(aq) + D-fructose(aq), K0 = 128 +/- 10 and delta H0 = 2.21 +/- 0.10 kJ mol-1; alpha-D-melibiose(aq) + H2O(liq) = D-galactose(aq) + D-glucose(aq), K0 = 123 +/- 42 and delta H0 = -0.88 +/- 0.50 kJ mol-1; palatinose(aq) + H2O(liq) = D-glucose(aq) + D-fructose(aq), delta H0 = -4.44 +/- 1.1 kJ mol-1; D-trehalose(aq) + H2O(liq) = 2 D-glucose(aq), K0 = 119 +/- 10 and delta H0 = 4.73 +/- 0.41 kJ mol-1; D-turanose(aq) + H2O(liq) = D-glucose(aq) + D-fructose(aq), delta H0 = -2.68 +/- 0.75 kJ mol-1; and 3-o-beta-D-galactopyranosyl-D-arabinose(aq) + H2O(liq) = D-galactose(aq) + D- arabinose(aq),0H0 = 107 +/- 10 and delta H0 = 2.97 +/- 0.10 kJ mol-1.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Thermodynamics of hydrolysis of disaccharides. Lactulose, alpha-D-melibiose, palatinose, D-trehalose, D-turanose and 3-o-beta-D-galactopyranosyl-D-arabinose. 187 72


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