Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound   Target Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound

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Query: KEGG:D03345 (beta-Galactosidase)
434 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

beta-Galactosidase activity was investigated in one case of juvenile GM1-gangliosidosis. This patient exhibited normal activity of the neutral form of beta-galactosidase (measured as beta-glucosidase activity) and normal pH curve of residual acid beta-galactosidase activity in leucocytes and fibroblasts. A shift towards more neutral pH optimum was seen in the beta-galactosidase enzyme occurring in serum. The communication also presents a study of the relationship of the different beta-galactosidases in human liver using isolated urine oligosaccharide from this patient as a beta-galactoside substrate. The other natural beta-galactoside substrates used in this investigation were different oligosaccharides, one glycopeptide and ceramide-beta-galactosidase. The beta-galactosidase forms with acidic pH optimum towards synthetic substrate (A forms) exhibit activity towards the natural substrate (except ceramide-beta-galactoside). The "neutral" beta-galactosidase with broad substrate specificity (B form) which includes beta-glucosides had no activity towards the natural substrates used. It could also be shown that the activity towards ceramide-beta-galactoside was a third type of beta-galactosidase different from A and B forms.
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PMID:beta-D-galactosidase activities in juvenile GM1-gangliosidosis. 3 Oct 52

A 28-month-old child was found to have several clinical features of lysosomal storage diseases, including: coarse facies, hepatosplenomegaly, lumbar kyphosis due to hypoplastic beaked L1 and L2 vertebral bodies, vacuolated lymphocytes in blood smears and rare foamy hystiocytes in bone marrow. However, no signs of neurological or ocular abnormalities were detected. A beta-galactosidase deficiency was demonstrated in leukocytes and cultured skin fibroblasts, with a residual activity toward 4-methylumbelliferyl-beta-galactopyranoside ranging between 5 and 15% of the normal mean. Normal activities were found for several other lysosomal acid hydrolases. beta-Galactosidase activities in leukocytes and cultured skin fibroblasts from both parents were within the normal ranges. The patient seems to represent an atypical expression of acid beta-galactosidase deficiency, since his clinical picture does not exaclty correspond to that of either the two classical types of GM1-gangliosidosis or other atypical patients reported in the literature havining beta-galactosidase deficiency.
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PMID:Atypical expression of beta-galactosidase deficiency in a child with Hurler-like features but without neurological abnormalities. 9 48

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

beta-Galactosidase activities were studied in livers and leukocytes of mucopolysaccharidoses and mucolipidoses (I-cell disease and adult "beta-galactosidase deficiency" with macular cherry-red spots). Marked deficiency of hepatic 4-methylumbelliferyl (4MU) and GM1 beta-galactosidases was demonstrated in these diseases. Leukocyte GM1 beta-galactosidase was also deficient in mucolipidoses. The parents of the patients with I-cell disease and "beta-galactosidase deficiency" had normal beta-galactosidase activity in plasma and leukocytes, compared to the low enzyme activity in heterozygous carriers of GM1-gangliosidosis. The cause of this enzyme deficiency in these diseases is not clear at present. It seems to be affected seondarily by exgenous factors such as unknown stored materials in the cells. Mucopolysaccharides were not increased in the livers of two cases of I-cell disease and a case of "beta-galactosidase deficiency".
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PMID:beta-Galactosidase in mucopolysaccharidoses and mucolipidoses. Deficiency of GM1 beta-galactosidase in liver and leukocytes. 40 36

The metabolism of galactosylceramide was investigated in normal and twitcher mice, an animal model for human globoid cell leukodystrophy. The findings were compared with data obtained on human tissues. In vitro studies demonstrated that there were two genetically distinct enzymes that hydrolyze galactosylceramide: galactosylceramidase I and II. The former was deficient in the twitcher, while the latter was intact. beta-Galactosidase preparations purified from normal mouse liver possessed the activity to hydrolyze galactosylceramide when the assay conditions for galactosylceramidase II was used. Therefore, galactosylceramidase II was considered to be identical to GM1 ganglioside beta-galactosidase. In contrast to the human enzyme, the murine beta-galactosidase had a relatively high Km value toward galactosylceramide. The galactosylceramide-loading test demonstrated that the twitcher fibroblasts hydrolyzed the lipid at lower rates than seen in cases of human globoid cell leukodystrophy fibroblasts. These differences in galactosylceramidase II between murine and human tissues suggest that galactosylceramide accumulates in twitcher mice but not in humans with globoid cell leukodystrophy, even though galactosylceramidase I is genetically deficient in both human and this mouse model.
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PMID:Metabolism of galactosylceramide in the twitcher mouse, an animal model of human globoid cell leukodystrophy. 309 85

Two GM1-beta-galactosidases, beta-galactosidases I, and II, have been highly purified from bovine brain by procedures including acetone and butanol treatments, and chromatographies on Con A-Sepharose, PATG-Sepharose, and Sephadex G-200. beta-Galactosidase I was purified 30,000-fold and beta-galactosidase II 19,000-fold. Both enzymes appeared to be homogeneous, as judged from the results of polyacrylamide disc gel electrophoresis. Enzyme I had a molecular weight of 600,000-700,000 and enzyme II one of 68,000, as determined on gel filtration. On sodium dodecyl sulfate polyacrylamide slab gel electrophoresis under denaturing conditions, enzyme II gave a single band with a molecular weight of 62,000, while enzyme I gave two minor bands with molecular weights of 32,000 and 20,000 in addition to the major band at 62,000. Both enzymes liberated the terminal galactose from GM1 ganglioside and lactosylceramide but not from galactosylceramide. Enzyme I showed a pH optimum of 4.0 and was heat stable, while enzyme II showed a pH optimum of 5.0 and lost 50% of its activity in 15 min at 45 degrees C. Enzyme I showed a pI of 4.2 and enzyme II one of 5.9.
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PMID:Purification and properties of GM1 ganglioside beta-galactosidases from bovine brain. 309 83

beta-Galactosidase has been purified from rabbit brain by a procedure which gives substantially greater purification and yield than the previously reported method. The enzyme was solubilized in 4% aqueous butanol and purified by a procedure which included affinity chromatography on columns of concanavalin A - Sepharose (ConA-Sepharose) and aminophenylthiogalactoside Sepharose (APT galactoside-Sepharose). The activity was resolved by DEAE-Sepharose chromatography into two fractions; the first did not bind to the column and was eluted in the unbound fraction, while the second bound to the column and could be eluted with a salt gradient. The unbound and bound fractions were purified 7600-fold and 4900-fold, respectively, by the newly developed procedure. Both gave two closely migrating protein bands on polyacrylamide gel electrophoresis and the major contaminating protein was beta-hexosaminidase in each case. The enzyme in the unbound fraction had an isoelectric point (pI) of 6.7 and an apparent molecular weight by gel filtration of 114 000 +/- 10 000. The enzyme that bound to DEAE-Sepharose at pH 8.0 and comprised about 60% of the total acid beta-galactosidase activity of rabbit brain eluted from Sephacryl S-200 as a single peak with apparent molecular weight 140 000 +/- 10 000. The two fractions displayed similar relative specific activities towards the synthetic substrates and ganglioside GM1 and lactosyl ceramide. Neither enzyme hydrolyzed galactosyl ceramide. We have immunological evidence which suggests that the two fractions of beta-galactosidase are also structurally related.
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PMID:Improved purification of beta-galactosidase from rabbit brain: two separable fractions share kinetic and structural properties. 641 4

beta-Galactosidase from T. cornutus was resolved into two activity peaks by gel filtration column chromatography. The pH optima of the two peaks designated P1 and P2, were 5.5 and 3.0, respectively, when p-nitrophenyl-beta-D-galactopyranoside was used as the substrate. The molecular weights of P1 and P2 were 700,000 +/- 70,000 and 78,000 +/- 7800, respectively, when estimated by gel filtration chromatography. The activities of both forms of the enzymes are stimulated by anions such as Cl-, Br- and NO-3. While the activity of P1 was stimulated by low anion concentrations, P2 requires 700 times higher anion concentration for similar enhancement of activity. P1, the high molecular weight form hydrolyzes mainly galactose from small molecular weight beta-galactosides, such as p-nitrophenyl-beta-D-galactopyranoside, 4-methylumbelliferyl-beta-D-galactopyranoside, lactose, lactosylceramide and 3-O-beta-D-galactopyranosyl-D-arabinose, whereas P2, the low molecular weight form cleaves, in addition, all the beta-galactosides tested, including 2-hexadecanoylamino-4-nitrophenyl-beta-D-galactopyranoside, GM1-ganglioside, asialo-GM1-ganglioside, asialo fetuin, alpha 1-acid glycoproteins and the tryptic peptides of the glycoproteins. The optimal conditions for the hydrolysis of the terminal galactose from GM1-ganglioside which does not occur in gastropods, such as T. cornutus, was found to require 40 mM NaCl and 1 mM sodium taurodeoxycholate at pH 3.0 in 50 mM sodium citrate buffer, conditions similar to those by mammalian beta-galactosidase.
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PMID:A beta-galactosidase isoenzyme from Turbo cornutus with substrate specificity toward GM1-ganglioside and glycoproteins. 641 42

beta-Galactosidase (beta-D-galactoside galactohydrolase, EC 3.2.1.23) purified from Aspergillus oryzae was modified with 2,4,6-trichloro-s-triazine derivatives of polyethylene glycol (activated BPEG) having molecular weights of 600, 1500, 2000, and 4000. Polyethylene glycol derivatives were attached to 6 of the 12 amino groups exposed on the surface of the enzyme. Upon modification, the enzymatic activity for a water-soluble substrate, o-nitrophenyl beta-D-galactopyranoside, was reduced with increasing molecular weight of the activated BPEG. On the contrary, the enzymatic activity for another substrate, 4-methylumbelliferyl beta-D-galactopyranoside, was increased upon modification. The Michaelis constants of native and modified enzymes for these two substrates were virtually the same. The effect of the modification was more marked in the enzymatic hydrolysis of the beta-galactosidic bond of amphipathic substrates. A fluorescent analog of naturally occurring galactocerebroside, 1-O-galactosyl-2-N-(1-dimethylaminonaphthalene-5-sulfonyl)-sphingosine, was hydrolyzed more rapidly by the modified enzyme than by the native one. The enzyme modified with activated BPEG of 1500 Da had the highest activity for this substrate. The beta-galactosidic bond of the terminal galactose of GM1-ganglioside (II3NeuAcGgOse4Cer, galactosyl-N-acetylgalactosaminyl-(N-acetylneuraminosyl)-galactosyl -glucosylceramide) was cleaved by the modified but not by the native enzyme.
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PMID:Alteration of the substrate specificity of Aspergillus oryzae beta-galactosidase by modification with polyethylene glycol. 643 28

The turnover of lysosomal beta-galactosidase was studied in fibroblast cultures from patients with Gm1-gangliosidosis and combined beta-galactosidase and neuraminidase deficiency, which had 5-10% residual beta-galactosidase activity. beta-Galactosidase was specifically inactivated with the suicide substrate beta-D-galactopyranosylmethyl-p-nitro-phenyltriazene (beta-Gal-MNT) and from the subsequent restoration of enzyme activity in cell cultures turnover times were calculated. By using [3H]beta-Gal-MNT, the hydrolytic activity per molecule of beta-galactosidase was determined. 3H-labelled beta-D-galactopyranosylmethylamine, the precursor of [3H]beta-gal-MNT, was obtained by Raney-nickel-catalysed exchange with 3H2O. The rate of synthesis of beta-galactosidase in normal and all mutant cells tested was found to be 0.4-0.5 pmol/day per mg of cellular protein. The GM1-gangliosidosis cells tested contain the normal amount of 0.5 pmol of beta-galactosidase/mg of protein with a normal turnover time of about 10 days, but only 10% of beta-galactosidase activity per enzyme molecule. Cells with combined beta-galactosidase and neuraminidase deficiency contain only 0.3 pmol of beta-galactosidase/mg of protein with a decreased turnover time of 1 day and normal hydrolytic properties (200 nmol of 4-methylumbelliferyl galactoside/h pmol of beta-galactosidase).
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PMID:Turnover of beta-galactosidase in fibroblasts from patients with genetically different types of beta-galactosidase deficiency. 680 Mar 55


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