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

Three male siblings in a Japanese family were affected with beta-galactosidase-neuraminidase deficiency (galactosialidosis). One patient died at 45 years of age, and postmortem liver and brain tissues were studied enzymatically. The residual activity of neuraminidase was relatively high in these tissues. Neuraminidase activity did not change in the tissues after repeated freezing and thawing of the homogenates, whereas this enzyme in control tissues lost 30 to 60% of its activity. There was a profound deficiency of beta-galactosidase in the tissues of the patient. Michaelis constant, pH profiles, and cryostability were identical for the patient and control patients. Cathepsin B was moderately increased in activity in the patient's tissues.
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PMID:beta-Galactosidase-neuraminidase deficiency (galactosialidosis): clinical, pathological, and enzymatic studies in a postmortem case. 640 77

Neuraminidase activity in fibroblasts obtained from a patient with combined beta-galactosidase-neuraminidase deficiency (beta-gal-/neur-) was partially restored by fusion with two ML I cell lines and an ML II cell line. As observed with neuraminidase activity, beta-galactosidase also showed complementation with an increase in activity when beta-gal-/neur- fibroblasts were fused with an ML II or a GMI gangliosidosis cell line. Both GMI gangliosidosis and sialidosis fibroblasts secreted a "corrective factor" which, when added to medium above beta-gal-/neur- fibroblasts, was pinocytosed and partially corrected its deficiencies for these two enzymes. This partial correction of beta-galactosidase and neuraminidase activities persisted for at least 72 h after removal of the "corrective factor" from the medium. A "corrective factor" with similar properties was obtained from glycoproteins isolated by chromatography of human spleen homogenates on concanavalin A-Sepharose. Treatment of beta-gal-/neur- fibroblasts with leupeptin or EP475, two inhibitors of lysosomal thiol-proteases, partially restored beta-galactosidase activity but caused no significant improvement in neuraminidase levels. The partial corrective effect of leupeptin on beta-galactosidase activity persisted for at least 2 d after removal of the drug, even in the presence of cycloheximide.
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PMID:Complementation, cross correction, and drug correction studies of combined beta-galactosidase neuraminidase deficiency in human fibroblasts. 642 34

An adult case of mucolipidosis with beta-galactosidase and neuraminidase deficiencies is reported. The patient was a 35-year-old Japanese female with coarse face, lumbar vertebral beaking, action myoclonus, cerebellar ataxia, clouding of the cornea, macular cherry-red spots, hearing loss and vacuolated lymphocytes, but without mucopolysacchariduria. Her clinical symptoms developed at a late age with a slow progression. The enzyme activities of beta-galactosidase were deficient in leukocytes and cultured skin fibroblasts but normal in serum. Sialic acid-rich glycopeptides and oligosaccharides were increased in the urine. Neuraminidase activities toward fetuin, alpha-N-acetylneuraminosyl-(2 leads to 3) lactose and alpha-N-acetylneuraminosyl-(2 leads to 6) lactose were deficient in cultured fibroblasts. It is suggested that the main disturbance in the present case might be the catabolic process of glycoproteins and oligosaccharides due to neuraminidase deficiency.
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PMID:Adult mucolipidosis with beta-galactosidase and neuraminidase deficiencies. 677 51

The complex between lactase (beta-D-galactoside galactohydrolase, EC 3.2.1.23) and phlorizin hydrolase (glycosyl-N-acylsphingosine glycohydrolase, EC 3.2.1.62) has been purified from the proximal and distal regions of the small intestine of suckling rats. The two enzymes behaved differently on DEAE-cellulose ion-exchange chromatography and during electrophoresis in the presence and absence of sodium dodecyl sulphate (SDS), but they have very similar cyanoge bromide cleavage patterns. Kinetic studies on the proximal and distal enzymes showed the same pH optimum of 6.0 and the same heat stability at 45 degrees C, but a small difference in Km. Treatment of both enzymes with fucosidase, mannosidase or N-acetylhexosaminidase did not affect enzymic activity or electrophoretic mobility. Neuraminidase digestion abolished the electrophoretic differences and gave two active enzymes with similar isoelectric points.
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PMID:Isolation and characterization of the proximal and distal forms of lactase-phlorizin hydrolase from the small intestine of the suckling rat. 677 1

Gangliosides were isolated from purified preparations of human peripheral blood lymphocytes and neutrophils. Structural analyses and comparisons were performed by direct probe mass spectrometry and by degradation studies with the following enzymes: Escherichia freundii endo-beta-galactosidase; Clostridium perfringens and Arthrobacter ureafaciens neuraminidase; and jack bean beta-N-acetylhexosaminidase and beta-galactosidase. This combination of techniques allowed us to obtain carbohydrate composition and sequence information without the aid of methylation or carbohydrate compositional analyses using only 1-2 mg of purified gangliosides. On the basis of these studies we propose that human lymphocytes and neutrophils have gangliosides with the following structures. NeuAc alpha 2 leads to 3Gal beta 1 leads to 4Glc beta 1 leads to 1Cer Structure A NeuAc alpha 2 leads to ? GlcNAc beta 1 leads to 3Gal beta 1 leads to 4Glc beta 1 leads to 1Cer Structure B NeuAc alpha 2 leads to ? Gal beta 1 leads to 3,4GlcNAc beta 1 leads to 3Gal beta 1 leads to 4Glc beta 1 leads to 1Cer Structure C All three compounds were isolated from both cell types with structure A being the major lymphocyte ganglioside and structure C the major neutrophil ganglioside. Structure B is a novel ganglioside and may represent a leukocyte-specific glycosphingolipid. Neuraminidase degradation studies demonstrated that only one ganglioside species of each cell type contains an internally linked sialic acid residue, and on the basis of thin layer chromatographic analysis this component is the same as the major brain ganglioside, GM1 (II3-N-acetylneuraminosyl-gangliotetraosylceramide). In addition, large gangliosides with the general structure NeuAc alpha 2 leads to ?(Gal beta 1 leads to 3,4GlcNAc beta 1 leads to 3)n Gal beta 1 leads to 4Glc beta 1 leads to 1Cer were isolated. These results are discussed as they relate to blood group antigens and specific cell surface markers in human leukocytes.
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PMID:Isolation and structural characterization of human lymphocyte and neutrophil gangliosides. 678 May 55

Beta-Galactosidase was partially restored by protease inhibitors, leupeptin, chymostatin and E-64 in cultured fibroblasts from three patients with beta-galactosidase-neuraminidase deficiency. Pepstatin did not activate this enzyme. Neuraminidase was not affected by any of these compounds in the culture medium. It was concluded that the activating effect was produced by a specific inhibition of thiol proteases.
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PMID:Beta-galactosidase-neuraminidase deficiency: restoration of beta-galactosidase activity by protease inhibitors. 679 66

Neuraminidase deficiency has been demonstrated in cultured skin fibroblasts of patients who have adult type sialidosis with partial beta-galactosidase deficiency. A substantial amount of residual enzyme activity has been observed in leukocytes, however. To explain this discrepancy, the nature and distribution of the enzyme were studied. Neuraminidase activity was higher in lymphocytes than in granulocytes of normal controls. In patients' lymphocytes, neuraminidase activity was profoundly decreased and total sialic acid contents were increased 2.3-fold. Two neuraminidases, one sonication-labile and the other sonication-stable, were found in lymphocytes; the former was predominant in cultured skin fibroblasts. The defective enzyme in this disorder was found to be the sonication-labile neuraminidase in both cultured skin fibroblasts and lymphocytes.
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PMID:Neuraminidase deficiency and accumulation of sialic acid in lymphocytes in adult type sialidosis with partial beta-galactosidase deficiency. 680 93

Acidic glycolipids from guinea pig macrophages enhance the response of macrophages to migration inhibitory factor (MIF), suggesting a role of glycolipid receptors for this lymphocyte mediator. Neuraminidase treatment of these glycolipids results in the loss of their biologic activity. This activity remains intact after incubation of the glycolipids with beta-galactosidase. In order to investigate whether sialic acid is essential for the macrophage's response to MIF, macrophages were incubated with neuraminidase. Neuraminidase treatment of peritoneal exudate cells results in the abrogation of macrophage responsiveness to MIF. Other exoglycosidases such as beta-galactosidase and beta-glucosidase had no effect upon the macrophage response. The effect of neuraminidase was found to be reversible within 18 hr. These experiments suggest that macrophage glycolipids containing sialic acid are components of the macrophage receptor for MIF.
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PMID:Role of sialic acid in the macrophage glycolipid receptor for MIF. 698 12

We devised a sensitive method to assay for neuraminidase activities towards alpha-(2 leads to 3)-N-acetylneuraminosyl hexasaccharide and alpha-(2 leads to 6)-N-acetylneuraminosyl hexasaccharide, which were isolated from the urine of a patient with adult sialidosis with partial deficiency of beta-galactosidase. Standard assay conditions for the determination of these neuraminidase activities were established and the radiolabeled reduced derivatives of these substrates were used. The fibroblast neuraminidase had its maximum activity at pH 4.0-4.2, with Km values of 2.22 X 10(-3) and 4.17 X 10(-3) mol/l and Vmax values of 76.9 and 28.6 nmol . mg-1 protein . h-1 towards the 2 leads to 3 isomer and the 2 leads to 6 isomer, respectively. Neuraminidase deficiencies were found in the fibroblasts of adult sialidosis, mucolipidosis II and III. These studies were compared with the neuraminidase activity towards alpha-(2 leads to 3)-N-acetylneuraminosyl lactose.
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PMID:Radioassay method of neuraminidase towards N-acetylneuraminosyl hexasaccharides. 706 Feb 78

Neuraminidase or sialidase (EC 3.2.1.18, acylneuraminyl hydrolase) from a strain of the influenza virus A (H3N2), identical to the A/Hong Kong/68 (H3N2) strain, has been purified and characterized by electrofocusing; only about 20% of the previous enzymic activity was lost after electrofocusing. The enzyme activity was measured by the peryodate-thiobarbiturate procedure, by the methoxyphenol-antipyrine method, and by spectrophotometry at 340 nm of the NADH produced in the oxidation of the beta-galactose + NAD+; this beta-galactose was released from lactose by beta-galactosidase; and lactose was liberated from N-acetylneuraminyl-lactose by the neuraminidase activity. The results of the interference by some chemical compounds, which are not true inhibitory agents for the enzyme, on the peryodate-thiobarbiturate reaction are indicated, as well as the detection of other compounds which are true inhibitors of this enzyme in vitro. This neuraminidase was able to release sialic acid with linkages alpha 2-3, alpha 2-6 and alpha 2-8 from several substrates, but with very different efficiency. Natural substrates such as the oligosaccharide N-acetylneuraminyl-lactose, glycoproteins (fetuin, bovine horse brain, colominic acid, and synthetic substrates such as 5-N-acetyl-2-O-(3-methoxyphenyl)-alpha-D-neuraminic acid and 2'-(4-methyl umbellyferil)-alpha-D-N-acetylneuraminic acid were hydrolyzed by this enzyme. Finally, the finding of neuraminidase in ovine, equine and porcine platelet is summarized.
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PMID:[Neuraminidase of influenza virus]. 714 96


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