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)

Cells of Entamoeba histolytica grown over a period of four days contained NADP+-dependent alcohol dehydrogenase exclusively inside the cells. No activity of this enzyme could be found in the growth medium after harvesting the cells. Under the same conditions, acid phosphatase, beta-N-acetylglucosaminidase, esterase, alpha-glucosidase, and different amylases of the parasite were found both inside the cells and in the medium. The activities present in the cell homogenate and in the medium before and after growth of the amoebas were partially separated by gel filtration on Sephadex G150 and G75, respectively. The comparison of the elution diagrams revealed that NADP+-dependent alcohol dehydrogenase, acid phosphatase, esterase, and amylases occurred as multiple forms inside the cells. These activities, as well as beta-N-acetylglucosaminidase and alpha-glucosidase, were released into the extracellular environment to a different degree. The enzymes originating from the parasite were identified and distinguished from those of the ingredients of the growth medium according to their molecular mass and pH optimum. Furthermore, the amoebic origin of the secreted enzymes was shown on the basis of their inhibition by antibodies prepared against the supernatant fraction of the homogenate.
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PMID:Secretory hydrolases of Entamoeba histolytica. 245 86

beta-Fructofuranosidase, alpha-glucosidase, beta-glucosidase, alpha-mannosidase, beta-mannosidase, sucrose phosphorylase, glucosyltransferase and fructosyltransferase were separated by isoelectric focusing and sensitively detected to be slightly diffuse and insoluble spots in thin-layer gels, supported by a glass plate, by release of monosugars or a sugar phosphate, followed by conversion to glucose-6-phosphate (G6P) and then by reduction of NADP+ to NADPH, terminated by the formation of reduced Nitroblue Tetrazolium (NBT). Approximately 1-10 mU of enzyme was focused and the gel, after washing with a buffer, was partially dried and directly stained by uniformly spreading on the gel surface a staining medium containing sucrose or nitrophenyl glycosides as substrates, intermediary enzymes such as hexokinase, mutase and/or isomerase, NADP+, ATP, Mg+, phenazine methosulfate (PMS) and NBT. Specific staining procedures for each of these activities, on sucrose or on the glycosides as substrates, and staining procedures for multiple activities are described, with the conditions necessary for optimal development.
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PMID:Glucose, fructose, mannose and/or glucose-1-phosphate-releasing activity stains for glycosidases and glycosyltransferases in gels after isoelectric focusing. 751 61

Glycosidases and glycosyltransferases were electrophoresed in the presence of sodium dodecyl sulfate (SDS) in a thin-layer gel supported by a glass plate, treated with the nonionic detergent Triton X-100, and specifically stained for the sugar-releasing activity of these enzymes. Staining is based on conversion of monosugars or a sugar phosphate to glucose-6-phosphate by the appropriate intermediary enzymes, reduction of NADP+ to NADPH, and accumulation of reduced Nitroblue Tetrazolium in the gel. Among the enzymes tested, alpha-glucosidase, beta-glucosidase and beta-mannosidase could not be renatured, whereas beta-fructofuranosidase and alpha-mannosidase could be renatured unless heated before electrophoresis. Sucrose phosphorylase, glucosyltransferase and fructosyltransferase, which are single-peptide proteins with no cystine bond, could be renatured even after pretreatment with SDS and/or mercaptoethanol at 100 degrees C for 10 min. However, exclusive heating remarkably decreased the activities of these enzymes. Two-dimensional separation of the five renaturable enzymes was done in a single thin-layer gel, using SDS-electrophoresis in the first dimension and isoelectric focusing in the second dimension.
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PMID:Renaturation and activity staining of glycosidases and glycosyltransferases in gels after sodium dodecyl sulfate-electrophoresis. 752 70