Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:3.2.1.23 (beta-galactosidase)
 14,648 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Clinical and neuropathological studies of a case of AB variant GM2-gangliosidosis have been presented. The patient was a 14 months old black female infant who had "black cherry spot" in the retinas. The total activities of beta-galactosidase and N-acetyl-beta-hexosaminidase, as well as the proportion of hexosaminidase A and B components in her serum and leukocytes were normal when the assays were carried out with artificial fluorogenic substrate. Diagnosis of GM2-gangliosidosis AB variant was established by an abnormal increase of GM2-ganglioside in the biopsied brain tissue, similar to classical Tay-Sachs disease. Her clinical manifestation appeared to be similar but somewhat milder than those of classical Tay-Sachs disease. Light microscopic features of the cerebral biopsy were also closely similar to Tay-Sachs disease and Sandhoff disease but gliosis and neuronal loss were less pronounced. Electron microscopic study revealed numerous membranous cytoplasmic bodies (MCB) and zebra bodies in neurons. In addition, varieties of large intracytoplasmic inclusions in astrocytes, a feature distinctly different from classical Tay-Sachs disease, were observed. Numerous cytoplasmic inclusions were also present in oligodendroglia, pericytes and microglial cells.
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PMID:GM2-gangliosidosis, AB variant: clinico-pathological study of a case. 17 79

Normal human skin fibroblasts were grown in the presence of N-hexyl-O-glucosyl sphingosine (HGS), an inhibitor of aryl glucosidase and glucocerebrosidase. Tests of the cells with aryl glycosides showed that beta-glucosidase activity in the cells was drastically reduced while other enzyme activities (alpha-glucosidase, beta-galactosidase, and N-acetyl-beta-hexosaminidase) were normal or elevated. Exposure of cells to HGS for 28 days resulted in increased values for cell weight per plate, glucocerebroside concentration, and galactosyl-galactosylglucosyl ceramide concentration. The concentrations of total lipid, cholesterol, and protein were unchanged, as was the fatty acid distribution within the glycolipids. Chemically, the inhibitor-treated cells exhibited a model form of Gaucher's disease. Although many membranous cytoplasmic inclusions were induced by HGS, they were unlike the characteristic inclusions seen in individuals with the genetic disorder. Skin fibroblasts from a Gaucher patient showed no abnormalities in composition or appearance.
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PMID:The effects of N-hexyl-O-glucosyl sphingosine on normal cultured human fibroblasts: a chemical model for Gaucher's disease. 17 14

Coupling of ribonucleoprotein particles from L cells infected with vesicular stomatitis virus to a pre-incubated ribosomal system obtained from uninfected HeLa cells allowed synthesis of two proteins. G1 (molecular weight 63,000) and G2 (molecular weight 67,000), and all other proteins of vesicular stomatitis virus except the spike protein G (molecular weight 69,000). Analyses of the tryptic peptides showed that G1, G2, and G had identical peptide sequences. The synthesis of G2 required the presence of membranes; only G1 was synthesized in the absence of any membranes. G2 but not G1 was shown to be a glycoprotein by affinity chromatography on a concanavalin A-Sepharose column. Removal of sialic acid residues from G by neuraminidase resulted in a product having an identical mobility to G2. Digestion of G2 or G with a mixture of neuraminidase (EC 3.2.1.18), beta-galactosidase (EC 3.2.1.23), and beta-N-acetylglucosaminidase (EC 3.2.1.30), however, produced a protein of molecular weight 65,000. These data suggest that G2 is the desialated G and is formed by glycosylation of G1, which is the unglycosylated polypeptide backbone of G.
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PMID:Synthesis and glycosylation in vitro of glycoprotein of vesicular stomatitis virus. 19 4

Isoelectric focusing was used to investigate the multiple forms of acid phosphatase, arylsulfatase, beta-glucuronidase, beta-galactosidase and beta-N-acetylhexosaminidase in the following, previously characterized subcellular fractions from rat kidney: a special rough microsomal fraction, enriched up to 9-fold over the homogenate in acid hydrolases; a smooth microsomal fraction; a Golgi membrane fraction enriched about 2.5-fold in acid hydrolases and 10- to 20-fold in several glycosyl transferases; and a lysosomal fraction enriched up to 25-fold in acid hydrolases. The electro-focusing behavior of the hydrolases in these fractions was markedly sensitive to the autolytic changes that occur under acidic conditions, even at 4 degrees C. Autolysis was minimized by extracting fractions in an alkaline medium (0.2% Triton X-100, 0.1 M sodium glycinate buffer, pH 10, 0.1 % p-nitrophenyloxamic acid) and adding p-nitrophenyloxamic acid (0.1 %), AN INHIBITOR OF LYSOSOMAL NEURAMINIDASE AND cathepsin D, to the pH gradient. The enzymes in the lysosomal fraction displayed a characteristic bimodal or trimodal distribution. Arylsulfatase, beta-glucuronidase and beta-N-acetylhexosaminidase occurred in an acidic form with an isoelectric point of 4.4, and a basic form with an isoelectric point of 6.2, 6.7 and 8.0, respectively. Acid phosphatase and beta-galactosidase occurred in an acidic, intermediate and basic form with isoelectric points of about 4. 1, 5.6 and 7.4, respectively. In the special rough microsomal fraction these enzymes were mostly in a basic form with isoelectric points between 7.5 and 9; these were 1-2 units higher than the corresponding basic forms in the lysosomal fraction. Treatment of extracts of the rough microsomal fraction with bacterial neuraminidase raised the isoelectric points of all five hydrolases by 1-2.5 units, indicating the presence of some N-acetylneuraminic acid residues in these basic glycoenzymes. The hydrolases in the Golgi fraction were largely in an acidic form with isoelectric points similar to or lower than those of the corresponding acidic components in the lysosomal fraction. The hydrolases in the smooth microsomal fraction showed isoelectric-focusing patterns intermediate between those in the rough microsomal and the Golgi fractions. These findings support the following scheme for the synthesis, transport and packaging of the lysosomal enzymes. Each hydrolase is synthesized in a restricted portion of the r
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PMID:Changes in electronegativity of lysosomal hydrolases during intracellular transport. An isoelectric-focusing study in subcellular fractions of rat kidney. 23 56

K-m values of beta-N-acetylglucosaminidase (2-acetamido-2-deoxy-beta-D-glucoside acetamidodeoxyglucohydrolase EC 3.2.1.30), beta-N-acetylgalactosaminidase (EC 3.2.1.53), beta-galactosidase (beta-D-galactoside galactohydrolase EC 3.2.1.23) and alpha-L-fucosidase (alpha-L-fucoside fucohydrolase EC 3.2.1.51) of distal colonic tumours, induced in rats by 1,2-dimethylhydrazine, were found to be significantly different compared with the values for the enzymes of the colonic mucosa of the control and tumour-bearing animals and of the proximal colonic tumours. The inhibition kinetics data also showed a significant difference between the enzymes of the distal colon tumours and of other experimental tissues. The data on the effect of pH on enzyme kinetics (pK values) showed no significant difference in the catalytic groups of the active centres of enzymes from tumours and from the control colonic mucosa. Tumour beta-N-acetylglucosaminidase and beta-N-acetylgalactosaminidase compared with the enzymes from other experimental tissues were found to be different in their thermal inactivation kinetics. K-m values of 14 days old foetal intestinal beta-N-acetylglucosaminidase and beta-N-acetylgalactosaminidase were significantly different from the values obtained for the adult mucosal enzymes but were similar to those of the distal colonic tumour enzymes.
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PMID:Studies on the kinetics of glycosidases from chemically-induced rat colonic tumours and normal rat colon. 23 55

The yeast alpha-mannosidase [EC 3.2.1.24] was purified 1160-fold from the crude extract of the autolysate. The purified preparation was practically free from alpha-glucosidase, beta-glucosidase, alpha-galactosidase, beta-galactosidase, beta-mannosidase, and beta-N-acetylhexosaminidase activities. After the separation of yeast mannan during the purification procedures the enzyme became unstable but could be stored at 5 degrees C for three weeks with 50% loss of activity. The purified enzyme hydrolyzed both aryl and alkyl mannosides, but hydrolysis of yeast mannan proceeded slowly. Yeast mannan and Zn2+ increased the enzyme catalyzed hydrolysis of p-nitrophenyl mannoside, whereas NaN3, monoiodoacetate and methyl alpha-D-mannoside acted as inhibitors. The molecular weight was estimated to be 450,000 by gel filtration.
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PMID:Purification and properties of alpha-mannosidase from bakers' yeast. 33 3

Using fresh frozen, freeze-dried or cryostate sections from aldehyde fixed rat tissues 13 diazonium salts were tested as simultaneous coupling reagents for the localization of acid, neutral and alkaline hydrolases with azo indoxyl methods. Hexazotized new fuchsine and/or Fast blue B are the diazonium salts of choice for the demonstration of acid beta-galactosidase, neuraminidase, beta-N-acetylglucosaminidase, acid phosphatase, and non-specific esterase followed by hexazotized p-rosaniline. Fast blue VB, BB and RR and Fast violet B are recommended for the investigation of alkaline phosphatase and lactase, Fast garnet GBC for acid beta-galactosidase, glucosaminidase and lactase. Fast red B, RC, RL and TR and Fast black K can only be employed for lactase studies. The exact concentration of the coupling reagent depends on the activity of the enzyme and the organ imvestigated. On the average 0.01-0.02 ml unstable diazonium salt/ml and 0.3--1 microgram stable diazonium salt/ml are sufficient for the correct localization of these hydrolases. Freeze-dried cryostat sections yield the best results in the demonstration of lactase and alkaline phosphatase independent on the coupling reagent used. Sections from formaldehyde or glutaraldehyde fixed organs are superior for the localization of the other hydrolases; an exception is the investigation of acid beta-galactosidase and glucosaminidase with Fast garnet GBC. Then, excellent results are obtained also with freeze-dried material. Fresh frozen sections are suitable for the localization of lactase with hexazotized new fuchsine or p-rosaniline and of alkaline phosphatase with Fast blue VB and BB or violet B. The total activity of acid, neutral and alkaline hydrolases can be investigated using semipermeable membranes in combination with all unstable and stable diazonium salts of choice. Reliable osmification of the azoindoxyl dye is only possible if hexazotized p-rosaniline is employed for coupling; without further posttreatment all azoindoxyl dyes are extracted by ethanol, isopropanol or xylol. 7 incubation media are given for the demonstration of hydrolases with azoindoxyl methods at the level of light microscopy for routine studies and typical examples for the application of these methods are presented. A modified procedure is described for the freeze-drying of cryostat sections with the Edwards-Pearse tissue dryer EPD3.
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PMID:[Azoindoxyl methods for the investigation of hydrolases. IV. Suitability of various diazonium salts (author's transl)]. 36 63

Several lysosomal enzyme activities in cultured lymphoid cell lines were studied during 3 phases of cell culture; logarithmic growth phase, stationary phase and decline phase. Enzyme induction during cell growth was found in N-acetyl-hexosaminidase, beta-galactosidase and alpha-L-fucosidase, but no induction in alpha-D-mannosidase, alpha-glucosidase and beta-glucuronidase. The latter two enzymes were unchanged during all cell culture phases. A drop in alpha-L-fucosidase and alpha-D-mannosidase activity was found during the stationary and decline phases of cell culture.
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PMID:Lysosomal enzyme activities in cultured lymphoid cell lines. 41 May 67

B and T lymphocytes were separated by means of the spontaneous sheep red blood cell rosette formation technique from 3 normal donors. The following acid hydrolases were biochemically determined on separated B and T lymphocytes: acid phosphatase, beta-glucuronidase, beta-galactosidase, beta-hexosaminidase, alpha-arabinosidase, alpha-galactosidase, alpha-mannosidase, alpha-glucosidase, and pH 4.0 and pH 5.0 beta-glucosidase. The activities of most of the acid hydrolases including acid phosphatase and beta-glucuronidase were found to be slightly decreased in B lymphocytes when compared to T lymphocytes. However, alpha-mannosidase activity was found to be significantly higher in the B lymphocytes than in the T lymphocytes and offers the possibility of using this enzyme as a B lymphocyte marker.
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PMID:Acid hydrolases in normal B and T blood lymphocytes. 41 51

1. Shape change, aggregation and secretion of dense-granule constituents in platelets differ in their dependence on cellular energy metabolism. The possibility that such a difference also exists between secretion of dense-granule constituents and acid hydrolases was investigated. 2. Human platelets were incubated with [(14)C]adenine in plasma, and then washed and resuspended in salt solutions. The effects of incubating the cells with antimycin A and 2-deoxyglucose on the concentrations of [(14)C]ATP, ADP, AMP, IMP and inosine plus hypoxanthine and on thrombin-induced secretion of ATP plus ADP and acid hydrolases were studied. The metabolic inhibitors only affected (14)C-labelled nucleotides, whereas thrombin only liberated unlabelled ATP and ADP. 3. The extent of secretion decreased progressively with time during incubation with the metabolic inhibitors. At any time the secretion of acid hydrolases, beta-N-acetylglucosaminidase, beta-glucuronidase and beta-galactosidase was inhibited to a greater extent than secretion of ATP plus ADP (dense-granule secretion). 4. Incubation with the metabolic inhibitors shifted the log (dose)-response relationship to higher thrombin concentrations, and with a greater shift for acid hydrolase secretion than for dense-granule secretion. 5. Antimycin, when present alone, caused a marked decrease in the rate of acid hydrolase secretion, but had no effect on dense-granule secretion. 6. These results further support the view that acid hydrolase secretion and dense-granule secretion are separate processes with different requirements for ATP energy. Acid hydrolase secretion, but not dense-granule secretion, appears to depend on a simultaneous rapid generation of ATP, which can be accomplished by oxidative, but not by glycolytic, ATP production.
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PMID:Effects of antimycin A and 2-deoxyglucose on secretion in human platelets. Differential inhibition of the secretion of acid hydrolases and adenine nucleotides. 50 92


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