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)

We describe the characterization of a mutation of the locus GLR1. This mutation allowed for (i) the glucose repression-insensitive synthesis ot the enzymes maltase, galactokinase, alpha-galactosidase, reduced nicotinamide adenine dinucleotide-cytochrome c reductase, and cytochrome c oxidase and (ii) growth on maltose in the presence of the gratuitous glucose repressor D-glucosamine. The glucosamine resistance cosegregated with the glucose-insensitive synthesis of the enzymes listed above. In addition, crosses between the glucosamine-resistant mutant and isogenic sensitive strains gave only tetrads containing two resistant and two sensitive spores. Thus, a single pleiotropic mutation is responsible for both phenotypes. We call the locus GLR1, for glucose regulation, and the glucose repression-insensitive mutation glr1-1.
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PMID:Pleiotropic glucose repression-resistant mutation in Saccharomyces carlesbergensis. 720 32

Improvement of the delivery of exogenous enzymes is essential to achieve effective enzyme replacement therapy in lysosomal storage diseases. To test whether alpha 2-macroglobulin, an endogenous plasma protein, could serve as a transport vehicle of therapeutic agents to cells, alpha 2-macroglobulin and acid alpha-glucosidase or alpha-galactosidase A were coupled using two heterobifunctional cross-linking reagents. The alpha-glucosidase-alpha 2-macroglobulin conjugate was internalized and transported into lysosomes of acid alpha-glucosidase-deficient fibroblasts. The enzyme activity was stable after being taken up by the cells. Uptake of the conjugate resulted in the degradation of glycogen accumulated in lysosomes. The alpha-galactosidase A-alpha 2-macroglobulin conjugate was also internalized into the lysosomes of alpha-galactosidase A-deficient fibroblasts. Internalized alpha-galactosidase A-conjugate degraded globotriaosylceramide accumulated in lysosomes. The endocytosis of both conjugate was inhibited by alpha 2-macroglobulin-trypsin complex, indicating that the conjugates were endocytosed by an alpha 2-macroglobulin receptor system. These results showed the usefulness of alpha 2-macroglobulin as a transport vehicle of lysosomal enzymes for effective enzyme replacement.
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PMID:Lysosomal enzyme replacement using alpha 2-macroglobulin as a transport vehicle. 752 46

Seven pyranoses and three furanoses with a nitrogen in the ring were prepared by chemical synthesis, microbial conversion, and isolation from plants to investigate the contribution of epimerization, deoxygenation, and conformation to the potency of inhibition and specificity of mammalian glycosidases. The seven pyranoses are 1-deoxynojirimycin (1), the D-manno (2), D-allo (3), and D-galacto (4) isomers of 1, fagomine (1,2-dideoxynojirimycin, 5), and the D-allo (6) and D-galacto (7) isomers of 5, while the three furanoses are 2,5-dideoxy-2,5-imino-D-mannitol (8), 1,4-dideoxy-1,4-imino-D-arabinitol (9), and 1,4-dideoxy-1,4-imino-D-ribitol (10). The 2-deoxygenation and/or 3-epimerization of 1 enhanced the potency for rat intestinal lactase and bovine liver cytosolic beta-galactosidase. Especially compound 6 showed a potent inhibitory activity against both enzymes, and compound 8, a mimic of beta-D-fructofuranose, was a potent inhibitor of both beta-galactosidases as well. Compound 4, which has been known as a powerful alpha-galactosidase inhibitor, exhibited no significant inhibitory activity for most of mammalian beta-galactosidases. In addition, compound 6 fairly retained a potency of 1 toward rat intestinal isomaltase. In this study, compound 8, known as a processing alpha-glucosidase I inhibitor in cell culture, has been found to have no effect on processing alpha-glucosidase II, whereas 9 has been shown to be a good nonspecific inhibitor of intestinal isomaltase, processing alpha-glucosidase II, Golgi alpha-mannosidases I and II, and porcine kidney trehalase. It has been speculated that glycosidase inhibitors have structures which resemble those of the respective glycosyl cations. This Broad inhibitory activity of 9 toward various glycosidases suggest that it superimposes well on the various glycosyl cations.
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PMID:Nitrogen-in-the-ring pyranoses and furanoses: structural basis of inhibition of mammalian glycosidases. 796 30

Seven oligosaccharides were isolated from alpha-D-glucosidase (EC 3.2.1.20) from Aspergillus niger, and the structures of these oligosaccharides were studied by 1H NMR spectroscopy. After treatment of the alpha-D-glucosidase with N-glycosidase F, seven major oligosaccharide peaks were detected by Dionex anion-exchange HPLC. The structures corresponding to the three peaks OS-1, OS-2, and OS-4 were determined to be Man8GlcNAc2, Man9GlcNAc2, and GlcMan9GlcNAc2, respectively, from 1H NMR spectra of the isolated fractions. Each of the four oligosaccharides OS-5, OS-6, OS-7-1, and OS-7-2 contained an alpha-D-galactofuranosyl residue (Galf) linked to Man(A) via an alpha-(1-->2)-linkage. OS-7 was found to consist of two oligosaccharides. The structures of these four oligosaccharides were determined to be GalfMan5GlcNAc2, GalfMan6GlcNAc2, GalfMan7GlcNAc2, and GalfMan8GlcNAc2 by 1H NMR spectroscopy and compositional analysis. The Galf structure of GalfMan5GlcNAc2 was found to be identical to that of an oligosaccharide previously isolated from the alpha-D-galactosidase of the same strain. The structure of OS-3 remains undetermined.
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PMID:Novel structures of N-linked high-mannose type oligosaccharides containing alpha-D-galactofuranosyl linkages in Aspergillus niger alpha-D-glucosidase. 819 71

Lysosomal storage diseases (LSD) are caused by deficient activity of specific lysosomal enzymes. Early diagnosis and selective termination is still the trend of therapy. The purpose of this study was to establish an assay system and investigate the reference range of lysosomal enzyme activity of cultured fetal cells in the Chinese population. Seventy amniotic fluid and 9 chorionic villi samples were collected and cultured in this study. Enzyme activity assay was done by synthesized 4-Mu-binded substrates. The activity was expressed as nmol/mg protein/hour. In cultured amniotic cells, the results showed 14-138 of alpha-glucosidase, 8-133 of alpha-galactosidase, 32-470 of alpha-mannosidase, 101-1121 of alpha-fucosidase, 106-1321 of beta-galactosidase, 15-268 of beta-glucosidase, 11-279 of beta-glucuronidase, 101-1193 of Hexosaminidase A, and 886-6204 of N-acetyl-alpha-glucosaminidase. In cultured chorionic villi samples, it showed 22-335 of alpha-glucosidase, 31-230 of alpha-galactosidase, 47-250 of alpha-mannosidase, 35-218 of alpha-fucosidase, 49-934 of beta-galactosidase, 34-329, of beta-glucosidase, 57-379 of beta-glucuronidase, and 328-3412 of Hexosaminidase A. The enzyme activity was not correlated with the gestation age when sample was obtained. Furthermore, there was no statistical significance among the range of amniotic cells, chorionic villi samples, skin fibroblasts and peripheral leukocytes for each enzyme studied. It is suggested that the synthesis of lysosomal enzymes has been mature since the early fetal state, and the samples obtained as early as 8 weeks of gestation age can be used for early diagnosis of lysosomal storage diseases.
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PMID:[Lysosomal enzyme activity of cultured fetal cells in Chinese and its clinical application]. 820 65

The alkaloid extract from roots of naturally growing Convolvulus arvensis, purified by ion-exchange chromatography, showed significant inhibitory activity toward beta-glucosidase and alpha-galactosidase. The demonstrated occurrence of polyhydroxy-nortropane alkaloids, the calystegins, in C. arvensis and their structural similarity to known polyhydroxy alkaloid glycosidase inhibitors, suggested that these might be responsible for the observed activity. Pure calystegins, isolated from transformed root cultures of the related plant species Calystegia sepium, were tested for glycosidase inhibitory activity. The purity of the alkaloids was established by gas chromatography and their identity confirmed by their mass spectrometric fragmentation patterns. The trihydroxy alkaloid, calystegin A3, was a moderately good inhibitor of beta-glucosidase (Ki = 4.3 x 10(-5) M) and a weak inhibitor of alpha-galactosidase (Ki = 1.9 x 10(-4) M). An increased level of hydroxylation, as in the tetrahydroxy calystegins B, consisting of 27% calystegin B1 and 73% calystegin B2, resulted in greatly enhanced inhibitory activity. The calystegins B were potent inhibitors of beta-glucosidase (Ki = 3 x 10(-6) M) and alpha-galactosidase (Ki = 7 x 10(-6) M). These levels of activity are comparable with those of the polyhydroxy indolizidine alkaloids castanospermine and swainsonine toward alpha-glucosidase and alpha-mannosidase, respectively, and of the polyhydroxy pyrrolizidine alkaloid australine toward alpha-glucosidase. The calystegins therefore compose a new structural class of polyhydroxy alkaloids, the nortropanes, possessing potent glycosidase inhibitory properties.
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PMID:Calystegins, a novel class of alkaloid glycosidase inhibitors. 832 1

This paper deals with microheterogeneity in the structure of O-linked sugars of carbohydrases secreted by Asp. awamori, namely glucoamylase, alpha-galactosidase and alpha-glucosidase. Microheterogeneity was found to be related both to post-secretion deglycosylation and to changes in transferase activity induced by the differences in culturing conditions.
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PMID:Microheterogeneity in O-type sugar chains of carbohydrases secreted by Asp. awamori. 835 22

An epidemiologic study of Pasteurella haemolytica serovar 1 (Ph1) in market-stressed feeder calves from 7 farms in eastern Tennessee was conducted. The nasal mucus of each calf was cultured sequentially at the farm of origin (day 0), at an auction market (day 133), and at a feedyard in Texas (days 141, 148, 155, and 169). Of the 103 calves tested, 77 were culture-positive, including 1 on day 0, 1 on day 133, 20 on day 141, 57 on day 148, 50 on day 155, and 14 on day 169. From the 143 Ph1 isolates, 20 enzyme profiles were determined by use of a commercial enzyme system that detects 19 enzymatic reactions; 4 antimicrobial susceptibility profiles were obtained, using the disk-diffusion method, which evaluated susceptibility to 11 antibacterial drugs. All isolates were positive for acid phosphatase and alkaline phosphatase, but were negative for alpha-galactosidase, alpha-mannosidase, beta-glucosidase, beta-glucuronidase, cystine aminopeptidase, N-acetyl-beta-glucosaminidase, and trypsin. Other positive enzyme reactions included: leucine aminopeptidase, 140 Ph1 isolates; phosphohydrolase, 90 isolates; alpha-fucosidase, 63 isolates; esterase (C4), 59 isolates; valine aminopeptidase, 30 isolates; esterase lipase (C8), 24 isolates; beta-galactosidase, 2 isolates; and alpha-glucosidase, chymotrypsin and lipase (C14), 1 isolate each. Thirty-four Ph1 profiles were identified, using combined enzyme and antimicrobial susceptibility profiles. The data indicate that the strains isolated during the feedyard period may have been determined more by farm of origin (P < or = 0.001) than by habitation with calves from other farms while in the feedyard.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Identification of Pasteurella haemolytica A1 isolates from market-stressed feeder calves by use of enzyme and antimicrobial susceptibility profiles. 842 78

The weakly beta-haemolytic isolates were divided into 56 electrophoretic types (ETs), contained in three distinct genetic groups (A,B and C). Group A corresponded to the genus Serpulina, and could be divided into three divisions. It contained 17 weakly haemolytic isolates in divisions b and c, as well as all 98 isolates of S. hyodysenteriae, located in division a. All seven weakly beta-haemolytic isolates that produced indole and had alpha-glucosidase but not alpha-galactosidase activity fell into division b. These spirochaetes may represent a distinct species. The other ten weakly beta-haemolytic spirochaetes, in division c, fitted the description of S. innocens. Group B contained 17 of the weakly beta-haemolytic isolates (18.9%) in ten ETs. Isolates in this group differed from typical S. innocens in that they lacked alpha-galactosidase activity. Group B represented a distinct group of weekly beta-haemolytic spirochaetes, which may constitute a new genus. Group C contained 56 of the weakly beta-haemolytic isolates (62.2%) located in 29 ETs. The original isolate from "spirochaetal diarrhoea" (P43/6/78-Taylor et al., 1980) was located in this group, together with Australian isolates from a similar condition. Spirochaetes in group C were morphologically distinct from those in groups A and B in that they possessed only four, five or occasionally six, subterminal axial filaments, were more slender, and had more pointed ends to their cells. We consider that group C represents a new genus of spirochaetes, members of which may be associated with spirochaetal diarrhoea.
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PMID:The porcine intestinal spirochaetes: identification of new genetic groups. 846 Apr 69

A combined evaluation of the phenotypical properties of five Serpulina type or reference strains and 163 Swedish isolates of spirochaetes from pigs and two from birds was made. The porcine isolates were collected from herds with a history of dysentery or severe diarrhoea and from herds chosen at random. On the basis of beta-haemolysis, indole production, hippurate hydrolysis, and alpha-galactosidase, alpha-glucosidase and beta-glucosidase activity, the isolates could be divided into four main groups, I to IV, with three subgroups in group III. Group I included the type strain for Serpulina hyodysenteriae (B78). Group II was differentiated from group I only by weak beta-haemolysis. Group III included the type strain for Serpulina innocens (B256). Group IV included the pathogenic, weakly haemolytic strain P43. Group IV-spirochaetes were characterised by their ability to hydrolyse hippurate and by their lack of beta-glucosidase activity. Group I and II-spirochaetes were isolated only from dysenteric or diarrhoeic pigs. There was a statistical relationship between pigs with diarrhoea and the isolation of group IV spirochaetes but no relationship with group III spirochaetes.
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PMID:Phenotypical characterisation of intestinal spirochaetes isolated from pigs. 852 77


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