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)

The properties of beta-galactosidase of tears were investigated and the standard assay system was accomplished. The pH optimum was 4.2. The enzyme had a KM of 8.3 X 10(-4) M. The activity was stimulated by chloride ions and slightly stabilized by bovine serum albumin. The activities of normal individuals were 205 +/- 80 (S.D.) nmol/h/ml. The activity in the tears of the patient with GM1 gangliosidosis decreased to about 20% of normal control and this disease could be diagnosed by the assay of beta-galactosidase in tears.
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PMID:The use of tears for diagnosis of GM1 gangliosidosis. 2 Oct 45

The type A or 'acid' and type B or 'neutral' beta-galactosidase activities have been measured in post-mortem liver samples from individuals dying of non-genetic diseases and patients dying of ganglioside storage disease other than GM1 gangliosidosis. The type A activities fell within the established normal range in all samples. The type B activities showed a biomodal distribution suggesting the occurrence of two distinct populations of human individuals. The greater proportion had activities within the range 11.67 pkat/mg of protein (+/- 3.33, S.D.), while others had lower activities in the range 0.48 pkat/mg of protein (+/- 0.38, S.D.). No clinical symptoms were associated with the much lower type B beta-galactosidase activities and it appears that this beta-galactosidase deficiency could be found in the original tissues. Methods of screening for type B beta-galactosidase deficiency are described and the significance of this enzyme deficiency is discussed.
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PMID:A benign deficiency of typeB beta-galactosidase in human liver. 2 31

The residual liver acid beta-galactosidase (beta-gal) activity from a case of feline GM1 gangliosidosis was partially purified and characterized with respect to its pH optimum, kinetic properties, thermostability, isoelectric point, molecular weight, and antigenicity. In comparison to the normal enzyme, the mutant enzyme had the same pH optima for the three substrates tested, a reduced Km for 4-methylumbelliferyl-beta-gal, elevated Km's for GM1 and asialofetuin (ASF), and increased thermolability. In addition, the mutant beta-gal had a higher isoelectric point, a reduced molecular weight, and appeared to be antigenically different from normal. The results suggest that the mutation in the Birmingham GM1 cat is structural and that the residual enzyme activity is a structurally altered acid beta-gal. The apparent lack of antigenic identity between the mutant and normal enzymes, in contrast to the situation in many human GM1 patients, is most unusual.
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PMID:Feline GM1 gangliosidosis: characterization of the residual liver acid beta-galactosidase. 8 95

The structural gene (beta GALA) coding for lysosomal beta-galactosidase-A (EC 3.2.1.23) has been assigned to human chromosome 3 using man--mouse somatic cell hybrids. Human beta-galactosidase-A was identified in cell hybrids with a species-specific antiserum to human liver beta-galactosidase-A. The antiserum precipitates beta-galactosidase-A from human tissues, cultured cells, and cell hybrids, and recognizes cross-reacting material from a patient with GM1 gangliosidosis. We have analyzed 90 primary man--mouse hybrids derived from 12 separate fusion experiments utilizing cells from 9 individuals. Enzyme segregation analysis excluded all chromosomes for beta GALA assignment except chromosome 3. Concordant segregation of chromosomes and enzymes in 16 cell hybrids demonstrated assignment of beta GALA to chromosome 3; all other chromosomes were excluded. The evidence suggests that GM1 gangliosidosis is a consequence of mutation at this beta GALA locus on chromosome 3.
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PMID:GM1-gangliosidosis: chromosome 3 assignment of the beta-galactosidase-A gene (beta GALA). 11 95

The common identity of human acidic beta-D-glucosidase (beta-D-glucoside glucohydrolase, EC 3.2.1.21) and beta-D-xylosidase (1,4-beta-D-xylan xylohydrolase, EC 3.2.1.37) as one enzyme and that of acidic beta-D-galactosidase (beta-D-galactoside galactohydrolase, EC 3.2.1.23), beta-D-fucosidase (no allotted EC number) and alpha-L-arabinosidase (alpha-L-arabinofuranoside arabinohydrolase, EC 3.2.1.55) as another enzyme is indicated by similar binding patterns of glycosidase activities of each enzyme to various lectins. by similar ratios between their intra- and extracellular levels in normal and I-cell fibroblasts and by their deficiencies in liver tissues from patients with Gaucher disease and GM1 gangliosidosis, respectively. A third enzyme, neutral beta-D-galactosidase, purified to homogeneity from human liver has been shown to possess all these five glycosidase activities at neutral pH. These neutral enzymic activities were not bound by any of the lectins examined and found to be reduced in liver and spleen of a patient with neutral beta-D-galactosidase deficiency. An additional form of beta-D-xylosidase with optimal activity at pH 7.4 was bound by the fucose-binding lectin from Ulex eurpaeus while no binding was observed for the acidic (pH 4.8) and neutral (pH 7.0) beta-D-xylosidase activities of the multiple glycosidase enzymes.
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PMID:Multiple carbohydrate-cleaving specificities in human acidic and neutral glycosidases. 11 23

Review of the data is presented on the hereditary disease gangliosidosis GM1 and on the enzyme beta-galactosidose, deficiency of which is responsible for this disease. Heterogeneity of the disease and existence of various forms of beta-galactosidase are considered. Possible correlation is discussed between the defects of the enzyme forms detected and the type of the disease.
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PMID:[Lysosomal beta-galactosidase properties and the molecular genetics of GM1 gangliosidosis]. 11 28

A clinical description of an apparently classical case of type 1 GM1 gangliosidosis is presented. The patient was the first-born child of first cousins. She was diagnosed at 6 weeks and died at 6 months. beta-Galactosidase activity was deficient in cultured fibroblasts using [3H]GM1 ganglioside and [3H]ceramide-lactose as substrates. Genetic complementation studies performed after cell fusion between cultured fibroblasts from the patient and from two other type 1, one type 2, and one juvenile GM1 gangliosidosis strain were positive with all strains. Subsequent studies revealed an increased excretion of a sialic acid-containing hexasaccharide in the patient's cells. Parents' fibroblasts contained normal levels of beta-galactosidase. The case emphasizes the variability of the clinical expression in sialidosis and the importance of demonstrating a primary gene defect in establishing a diagnosis of an inborn error or metabolism.
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PMID:Infantile sialidosis: a phenocopy of type 1 GM1 gangliosidosis distinguished by genetic complementation and urinary oligosaccharides. 11

Two cases of Gangliosidosis GM1 are presented. They are a child who showed psychomotor backward and generalized osteoporosis, died at 16 months, and a girl studied because of psychomotor backward when she was less than a year. This girl showed radiological vertebrae alterations similar to mucopolysaccharidosis and died when she was 7 years old. The enzymatic determinations in serum and cultured fibroblasts showed beta-galactosidase deficiency in both cases. Important storage of cerebral gangliosides with increase of the percentage of GM1 was also found in both cases. Histological alterations were found in some other organs besides the brain.
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PMID:[Gangliosidosis GM1. Clinical, radiologic, biochemical and histological studies in two cases (author's transl)]. 40 24

Normal quantities of GM1 beta-galactosidase cross reacting material (CRM) (0.31-0.47 microgram/mg protein) were detected by a sensitive radial immunodiffusion assay in skin fibroblasts from patients with GM1 gangliosidosis type 1 and adult variants, whereas elevated levels were found in GM1 gangliosidosis type 2 (0.41-0.72 microgram/mg protein). The specific activity of the immunologically CRM towards GM1 ganglioside of normal fibroblasts was about 500 times that of type 1, 100 times that of type 2, and 30 times that of the adult variants.
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PMID:Quantitation of the enzymically deficient cross reacting material in GM1 gangliosidoses. 41 18

In nine patients with GM1 gangliosidosis, liver ganglioside GM1 beta-galactosidase (EC 3.2.1.23) activity ranged from less than 0.01% to 0.05% of normal. In a tenth patient's liver, much higher activity was found (0.5% of normal). In this patient the residual enzyme had the same molecular weight as beta-galactosidase A, the major form of beta-galactosidase of normal human liver. No activity was found that corresponded to beta-galactosidase B, the minor form of human liver beta-galactosidase. On starch gel electrophoresis, the patient's enzyme migrated less anodally than normal beta-galactosidase A, both before and after treatment with neuraminidase. Beta-Galactosidase from the patient had a Km that was higher then normal; 5-fold higher with ganglioside GM1 and 2-fold higher with 4-methylumbelliferyl beta-galactoside. The patient's enzyme crossreacted immunologically with normal beta-galactosidase A and had about 100-fold more antigenic activity per unit catalytic activity than the normal enzyme. The results indicate that in this patient a beta-galactosidase A protein with altered charge and altered catalytic properties was present in relatively normal amounts, the first electrophoretic variant reported for a patient with a lysosomal hydrolase deficiency.
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PMID:An electrophoretic variant of beta-galactosidase with altered catalytic properties in a patient with GM1 gangliosidosis. 80 70


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