Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:3.2.1.20 (alpha-glucosidase)
 4,237 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Assay conditions were studied for eleven lysosomal enzymes (beta-D-galactosidase, alpha-D-mannosidase, beta-hexosaminidase, beta-D-glucuronidase, alpha-D-galactosidase, alpha-D-glucosidase, arylsulfatase, beta-D-glucosidase, alpha-L-fucosidase, alpha-D-neuraminidase and alpha-L-iduronidase) in cultured amniotic fluid cells (CAFC), cultured skin fibroblasts (CSF) and cultured embryonic lung fibroblasts (CELF), and the properties of the enzymes were compared among these cultured cells. In addition, changes in these enzymes from the three cell types were investigated between 4-6 earlier passages and 24-26 later passages. With the exception of alpha-D-glucosidase, alpha-D-neuraminidase and alpha-L-fucosidase, all enzymes assayed for the 4-6 earlier passages and the 24-26 later passages had the same Km values and the same pH optima, and were also unchanged with the increasing age of cell cultures, with regard to their points. The specific activities of beta-D-glucuronidase, arylsulfatase, alpha-D-glucosidase and beta-D-glucosidase for the 4-6 earlier passages increased significantly with development, though no change was observed with development in the specific activities of other enzymes. Variations were observed between the levels of these enzymes in the three cell types with the increasing age of cell cultures, such as increases in some, decreases in others and no change in still others.
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PMID:Comparative enzymology of eleven acid hydrolases in cultured amniotic fluid cells, skin fibroblasts and embryonic lung fibroblasts, and the respective changes with the increasing age of the cell cultures. 316 Dec 15

A panel of 42 rodent x cat somatic cell hybrids has been used to assign seven structural genes for lysosomal enzymes to specific chromosomes in the domestic cat. The assignments include alpha-glucosidase (GANAB) to chromosome D1, alpha-galactosidase (GLA) to the X chromosome, beta-galactosidase 1 (GLB1) to chromosome B3, beta-glucuronidase (GUSB) to chromosome E3, alpha-mannosidase A (MANA) to chromosome B3, alpha-L-fucosidase (FUCA) to chromosome C1, and hexosaminidase A (HEXA) to chromosome B3. In all cases, the feline lysosomal enzyme genes were located in linkage groups which were syntenic with their homologous positions in the human gene map. These assignments expand the genetic map of the cat and reaffirm the extensive syntenic homology between the chromosome maps of man and cat.
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PMID:Chromosomal mapping of lysosomal enzyme structural genes in the domestic cat. 322 Apr 74

We measured the activity of a non-lysosomal alpha-glucosidase with pH optimum near 6.0 in serum from a wide variety of patients, using the fluorogenic substrate, 4-methylumbelliferyl-alpha-D-glucopyranoside. Acutely ill patients with cystic fibrosis (CF) demonstrated significant increases in alpha-glucosidase compared with CF outpatients. The former group of CF patients experienced far more severe chronic pulmonary disease than did the latter, whereas both groups had similar degrees of gastrointestinal impairment. Patients with pancreatitis associated with trauma or complicated by severe necrosis, hemorrhage, or abscess also displayed greater increases in alpha-glucosidase than did patients with uncomplicated (edematous) pancreatitis. For CF outpatients and patients with either edematous pancreatitis or pancreatic cancer, the alpha-glucosidase activity was similar to that for the general hospital-patient population. Corresponding changes were not observed for other measured serum glycosidases (alpha-fucosidase, alpha-mannosidase, beta-glucuronidase, beta-N-acetylglucosaminidase). Measurement of serum alpha-glucosidase may be of value in assessing the clinical course in CF and in differentiating necrotizing from edematous pancreatitis.
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PMID:Measurement of alpha-glucosidase activity in serum from patients with cystic fibrosis or pancreatitis. 351 92

Castanospermine, an inhibitor of alpha-glucosidase activity, was injected into rats to determine its effects in vivo. Daily injections of alkaloid, at levels of 0.5 mg/g of body weight, or higher, for 3 days decreased hepatic alpha-glucosidase to 40% of control values, whereas alpha-glucosidase in brain was reduced to 25% of control values and that in spleen and kidney was reduced to about 40%. In liver, both the neutral (pH 6.5) and the acidic (pH 4.5) alpha-glucosidase activities were inhibited, but the former was more susceptible. On the other hand, beta-N-acetylhexosaminidase activity was elevated in the livers of treated animals, whereas beta-galactosidase activity was unchanged and alpha-mannosidase activity was somewhat inhibited. Livers of treated animals were examined by light and electron microscopy and compared to control animals to determine whether changes in morphology had occurred. In treated animals fed normal rat chow, the hepatocytes were smaller in size and simplified in structure, whereas the high-glucose diet lessened these alterations. Furthermore, in those animals receiving castanospermine at 1.0 mg or higher per g of body weight for 3 days, there was a marked decrease in the amount of glycogen in the cytoplasm, while a large number of lysosomes were observed that were full of dense, granular material. That this dense material was indeed glycogen was shown by the fact that it disappeared when blocks of fixed tissue were pretreated with alpha-amylase. Glycogen levels in liver, as measured either colorimetrically or enzymatically, were somewhat depressed at the higher levels of castanospermine.
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PMID:Castanospermine inhibits alpha-glucosidase activities and alters glycogen distribution in animals. 388 59

In order to study the intracellular localization of the proteolytic processing steps in the maturation of alpha-glucosidase and cathepsin D in cultured human skin fibroblasts we have used incubation with glycyl-L-phenylalanine-beta-naphthylamide (Gly-Phe-NH-Nap) as described by Jadot et al. [Jadot, M., Colmant, C., Wattiaux-de Coninck, S. & Wattiaux, R. (1984) Biochem. J. 219,965-970] for the specific lysis of lysosomes. When a homogenate of fibroblasts was incubated for 20 min with 0.5 mM Gly-Phe-NH-Nap, a substrate for the lysosomal enzyme cathepsin C, the latency of the lysosomal enzymes alpha-glucosidase and beta-hexosaminidase decreased from 75% to 10% and their sedimentability from 75% to 20-30%. In contrast, treatment with Gly-Phe-NH-Nap had no significant effect on the latency of galactosyltransferase, a marker for the Golgi apparatus, and on the sedimentability of glutamate dehydrogenase and catalase, markers for mitochondria and peroxisomes, respectively. The maturation of alpha-glucosidase and cathepsin D in fibroblasts was studied by pulse-labelling with [35S]methionine, immunoprecipitation, polyacrylamide gel electrophoresis in the presence of sodium dodecyl sulphate and fluorography. When homogenates of labelled fibroblasts were incubated with Gly-Phe-NH-Nap prior to immunoprecipitation, 70-80% of all proteolytically processed forms of metabolically labelled alpha-glucosidase and cathepsin D was recovered in the supernatant. The earliest proteolytic processing steps in the maturation of alpha-glucosidase and cathepsin D appeared to be coupled to their transport to the lysosomes. Although both enzymes are transported via the mannose-6-phosphate-specific transport system, the velocity with which they arrived in the lysosomes was consistently different. Whereas newly synthesized cathepsin D was found in the lysosomes 1 h after synthesis, alpha-glucosidase was detected only after 2-4 h. When a pulse-chase experiment was carried out in the presence of 10 mM NH4Cl there was a complete inhibition of the transport of cathepsin D and a partial inhibition of that of alpha-glucosidase to the lysosomes. Leupeptin, an inhibitor of lysosomal thiol proteinases, had no effect on the transport of labelled alpha-glucosidase to the lysosomes. However, the early processing steps in which the 110-kDa precursor is converted to the 95-kDa intermediate form of the enzyme were delayed, a transient 105-kDa form was observed and the conversion of the 95-kDa intermediate form to the 76-kDa mature form of the enzyme was completely inhibited.(ABSTRACT TRUNCATED AT 400 WORDS)
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PMID:Biosynthesis and intracellular transport of alpha-glucosidase and cathepsin D in normal and mutant human fibroblasts. 390 6

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

In the newborn lamb, activities of lysosomal enzymes are lower in the duodenum and jejunum than in the ileum. In contrast, there are only minor differences, if any, in activities of lysosomal enzymes between the regions of the small intestine of 5-day-old lambs. In the duodenum, jejunum and ileum, activities of hexosaminidase, alpha-mannosidase, beta-mannosidase, alpha-L-fucosidase and phosphodiesterase are greater in newborn than in 5-day-old lambs. Only in the distal part of the small intestine are activities of beta-glucuronidase, alpha-glucosidase, alpha-galactosidase, beta-galactosidase, acid phosphatase and cathepsin B higher in the newborn than in 5-day-old lambs. Cathepsin B activity is lower in the duodenum and jejunum of the newborn than in 5-day-old lambs.
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PMID:Lysosomal enzymes in the intestine of the newborn lamb. 609 93

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

The tertiary amines, procaine and nicotinoylprocaine, cause an increase in the specific activities of two glycohydrolases, alpha-fucosidase and beta-N-acetylhexosaminidase, which are involved in membrane metabolism. The specific activity of alkaline phosphatase, a plasma membrane enzyme, is lowered in muscle cells after addition of procaine or nicotinoylprocaine to the culture medium. The specific activities of two transferases, aspartate-amino-transferase and creatine phosphokinase, are increased by 10(-5) mol/l butacaine. A combined addition of butacaine and nicotinoylprocaine causes less effects on the transferases. The specific activities of neutral alpha-glucosidase and beta-N-acetylhexosaminidase are scarcely influenced by butacaine alone. Only butacaine and nicotinoylprocaine together lead to an increase of the activities of these hydrolases. These results suggest two different mechanism of action at least concerning these substances: 1. a specific binding of tertiary amines and 2. a coordinated mechanism on the membrane fluidity.
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PMID:[Effect of procaine, nicotinoylprocaine and butacaine on mammalian cells in culture]. 624 Feb 71


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