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 rumen fungi Neocallimastix patriciarum, Piromonas communis, and a morphologically distinct but unidentified isolate were cultivated on the polysaccharides starch, cellulose, xylan, and their principal component monosaccharides and disaccharides, and the range and specific activities of the glycoside hydrolases formed were monitored using gluco-oligosaccharide and p-nitrophenyl glycoside substrates. A wide range of enzyme activities was detected in preparations from vegetative growth and zoospores of all three isolates. Enzyme activity was also present in the culture medium. The specific activities were affected by the carbohydrate source available in the growth medium, although the more active hydrolases involved in the degradation of plant structural and storage polysaccharides were formed on all seven carbohydrate sources evaluated. Enzyme activities were increased in the zoospore, vegetative, and extracellular preparations after growth on the appropriate structurally related disaccharide or polysaccharide. The hemicellulolytic glycosidases (alpha-L-arabinofuranosidase, beta-D-xylosidase) were most active after growth on xylan, whereas alpha-/beta-glucosidase activity was increased with the corresponding glucan as growth substrate. However, whereas wide-ranging beta-glucosidase activity was detected following growth on maltose or starch, the alpha-glucosidase activities of P. communis were lower or undetectable in vegetative preparations grown on glucose or the beta-glucans cellobiose and cellulose.
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PMID:Glycoside hydrolase enzymes present in the zoospore and vegetative growth stages of the rumen fungi Neocallimastix patriciarum, Piromonas communis, and an unidentified isolate, grown on a range of carbohydrates. 360 11

Jejunal biopsies from six patients having the small bowel enteropathy associated with common variable immunodeficiency have been subjected to analytical subcellular fractionation and enzymic and regulatory peptide microassay to define the organelle pathology of this syndrome. Compared with normal subjects, the immunodeficient patients had decreased activities of the three brush border enzymes: alkaline phosphatase, gamma-glutamyl transferase and alpha-glucosidase. The other organelle marker enzyme activities and all the regulatory peptide concentrations did not differ from the controls. Density gradient experiments showed a complete loss of particulate beta-glucosidase (lactase) with activity entirely located in the cytosol. The integrity of other organelles was normal. These data indicate that the enteropathy of common variable immunodeficiency is associated with abnormalities in the jejunal brush border analogous to those present in tropical malabsorption syndrome.
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PMID:Jejunal mucosal enzyme activities, regulatory peptides and organelle pathology of the enteropathy of common variable immunodeficiency. 369 46

A novel substrate, beta-2-chloro-4-nitrophenylmaltopentaoside (beta CNPG5), was used for the enzyme-coupled determination of alpha-amylase in biological fluids. It was hydrolyzed specifically by alpha-amylase to about 90% producing beta-2-chloro-4-nitrophenylmaltoside (beta CNPG2) and maltotriose. Under the assay conditions, the absorption of 2-chloro-4-nitrophenol (CNP) generated by the secondary reaction of alpha-glucosidase and beta-glucosidase as auxiliary enzymes is about twice the absorption of 4-nitrophenol (PNP), which is the end product currently measured in some alpha-amylase assay methods. The sensitivity of the assay using beta CNPG5 was thus much higher than that using 4-nitrophenyl-maltopentaoside (PNPG5) as substrate. The absorption of CNP did not fluctuate with temperature or with pH between 6.8 and 7.2, which are the conditions normally used for determination of amylase activity in biological fluids.
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PMID:Determination of alpha-amylase in biological fluids using a new substrate (beta-2-chloro-4-nitrophenyl-maltopentaoside). 387 77

API ZYM and API An-Ident enzymatic substrate tests were done on six oral species which are difficult to characterize with conventional biochemical tests. "Bacteroides forsythus, the "fusiform" Bacteroides species (A. C. R. Tanner, M. A. Listgarten, M. N. Strzempko, and J. L. Ebersole, manuscript in preparation), is difficult to cultivate in broth media, yet it gave 15 positive tests in these series. The tests were able to separate this new species from species of Capnocytophaga and Fusobacterium. "B. forsythus" reactions were similar but not identical to those of reference Bacteroides species. Positive reactions for alpha-glucosidase, beta-glucosidase, alpha-fucosidase, and alpha-glucuronidase suggest that "B. forsythus" may be saccharolytic. It was the only species tested which was trypsin positive. Wolinella species, Campylobacter concisus, B. gracilis, and Eikenella corrodens are asaccharolytic, and characterization relies heavily on sensitivities to inhibitory agents. These species reacted weakly in the API ZYM and API An-Ident enzymatic substrate tests, and the reactions were not useful for separating these species. The enzyme reactions differentiated Wolinella recta and C. concisus from Selenomonas sputigena, another oral motile but saccharolytic organism.
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PMID:API ZYM and API An-Ident reactions of fastidious oral gram-negative species. 393 May 58

Intracellular beta-glucosidase was extracted from the mycelium of Th. aurantiacus, concentrated by DEAE-cellulose treatment, separated from alpha-glucosidase by hydroxylapatite chromatography and purified to electrophoretic homogeneity. Optimally active at 75 degrees C and pH 4.2, beta-glucosidase displayed complex kinetics with p-nitrophenyl-beta-glucoside which inhibited the enzyme at concentrations greater than 0.5 mM. With cellobiose the kinetics were practically hyperbolic at 70 degrees C (Hill coefficient nH = 1.09 and Km = 0.83 mM), but faint inhibition was observed at 50 degrees C. beta-glucosidase shares with alpha-glucosidase a high number of physicochemical properties: with similar aminoacid composition, very close isoelectric point (4.5 and 4.2), high molecular weight in the native state (175,000 and 140,000), the two enzymes showed the same behaviour on DEAE-cellulose, were equally stable at high temperature and were dissociated by 6 M urea to still active proteins. Furthermore, the carbohydrate contents of beta-glucosidase (17.6%) is not far from that previously determined for some forms of alpha-glucosidase (14-16%).
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PMID:Comparative study of glucosidases from the thermophilic fungus Thermoascus aurantiacus Miehe. Purification and characterization of intracellular beta-glucosidase. 393 99

The purification of beta-N-acetylhexosaminidase, alpha-glucosidase, alpha-mannosidase and beta-glucosidase from the spent growth medium of Dictyostelium discoideum strain Ax-2 myxamoebae is described. beta-N-Acetylhexosaminidase and alpha-glucosidase were obtained in high yield and as homogeneous preparations whereas the alpha-mannosidase preparation consisted of two electrophoretically distinct isoenzymes. The physical, chemical and kinetic properties of these enzymes are described.
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PMID:The purification and properties of extracellular glycosidases of the cellular slime mould Dictyostelium discoideum. 419 17

Axenic Tetrahymena pyriformis, syngen 1, mating type II cells were grown in Cox's defined medium. When washed and transferred into nonnutrient dilute salt solution or resuspended in the defined medium, the intact cells secrete acid hydrolases into the medium. Cells starving in the salt solution release in 5 hr about two-thirds of their beta-glucosidase, beta-N-acetylglucosaminidase, alpha-glucosidase, and amylase activities, about one-third of their deoxyribonuclease and phosphatase activities, smaller amounts of ribonuclease, and only a negligible fraction of their proteinase activity and protein content. During this period there is practically no change in the enzyme activities (except for a sudden increase of ribonuclease activity) and protein content of cells and medium together. Cells resuspended in the nutrient medium secrete enzymes as do the starved cells, but replace this loss, so that there is a continuous increase of the activities in the total system. According to isopycnic centrifugation experiments performed in sucrose gradients, the source of the hydrolases is a special population of lysosomes which disappear from the cells during starvation. This population equilibrates in the high density region of the gradients and contains the various acid hydrolases in about the proportion in which these enzymes appear in the medium.
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PMID:Secretion of acid hydrolases and its intracellular source in Tetrahymena pyriformis. 433 53

The enzymic hydrolysis of glycosyl fluorides is conveniently followed by using a pH-stat. Reactions involving glucosyl or galactosyl fluorides can also be followed by using glucose oxidase or galactose oxidase respectively. The pH-stat allows the rapid assay of intestinal alpha-glucosidase in crude homogenates. Use of glycosyl fluorides as substrates for glycosidases facilitates the polarimetric or g.l.c. determination of the anomeric nature of the initial product of hydrolysis. Hydrolysis by fungal amyloglucosidase proceeds with inversion of configuration whereas that by yeast and rat intestinal alpha-glucosidase, coffee-bean alpha-galactosidase and almond emulsin beta-glucosidase proceeds with retention of configuration. beta-d-Glucopyranosyl azide was not a detectable substrate for almond emulsin beta-d-glucosidase.
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PMID:The hydrolysis of glycosyl fluorides by glycosidases. Determination of the anomeric configuration of the products of glycosidase action. 512 11

In the course of screening amylase inhibitor producing, microorganisms, a strain identified as Streptomyces nigrifaciens NTU-3314 was found to have the highest inhibitor-producing ability among the other isolated strains. This strain was aerobically cultured at 30 degrees C in a 5l jar fermentor with a working volume of 2l. The optimum cultural medium consisted of defatted soybean flake 3.0%, potato starch 4.0%, casein 0.6%, sucrose 0.6%, serine 0.02% and NaCl 0.8% (pH 7.0). With an aeration rate of 1.5 vvm, an agitation speed of 300 rpm and an inoculum of 15% seed (previously grown in seed medium 3), the highest amount of inhibitor was obtained after 24 hours of cultivation. The amylase inhibitor produced had inhibitory effects on both alpha-amylase and glucoamylase, but not on beta-amylase, alpha-glucosidase, beta-glucosidase or dextranase. It was quite stable in 0.1M phosphate buffer (pH 7.0) and nearly 100% of its activity was retained even after boiling at 100 degrees C for 20 min.
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PMID:The microbial production of amylase inhibitor and its application. I. Isolation and cultivation of Streptomyces nigrifaciens NTU-3314. 608 1

Distinctive activities of various glycosidases were expressed in the cerebellum and cerebral cortex of mice during their development. In particular, N-acetyl-beta-D-hexosaminidase (EC 3.2.1.30) appeared to be developmentally regulated. A transient peak of enzyme activity at postnatal day 7 was characteristic for the cerebellum, whereas the activity in the cerebral cortex gradually increased through the 1st postnatal month and was maintained at a high level of activity throughout adulthood. The regulation of N-acetylhexosaminidase activity in the developing cerebellum of the staggerer mouse deviated clearly from enzyme activities in the wild-type, whereas the activity pattern in the staggerer cerebral cortex remained unaffected. In experiments mixing wild-type and staggerer cerebellum homogenates, the specific activity was additive. Thus, involvement of inhibitors or activating molecules can be excluded. This developmentally controlled regulation or disregulation in staggerer appears to be enzyme specific, sine beta-glucosidase, alpha-glucosidase, and beta-galactosidase did not exhibit such a pattern in either normal or staggerer mice. In the mutation weaver that, like staggerer, loses the majority of its cerebellar granule cells, N-acetyl-beta-hexosaminidase activity of the cerebellum was not elevated, indicating a specific defect in staggerer rather than a general effect on lysosomal enzymes due to cell death.
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PMID:Development-dependent regulation of N-acetyl-beta-D-hexosaminidase of cerebellum and cerebrum of normal and staggerer mutant mice. 621 96


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