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: EC:3.2.1.23 (beta-galactosidase)
14,648 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Interspecific somatic cell hybrids were analyzed by genetic complementation to determine if a lysosomal storage disease in sheep associated with deficiencies of beta-galactosidase and alpha-neuraminidase was homologous with any of four beta-galactosidase-deficient human diseases. Fibroblasts from beta-galactosidase-deficient sheep, cats, and human patients were fused and assayed histochemically for beta-galactosidase, with 5-bromo-4-chloro-3-indolyl beta-D-galactoside. We observed complementation in heterokaryons consisting of fibroblasts from beta-galactosidase-deficient sheep and fibroblasts from patients with galactosialidosis or mucolipidosis type II, but no complementation in heterokaryons consisting of fibroblasts from beta-galactosidase-deficient sheep and fibroblasts from human or feline GM1 gangliosidosis (type I) or from human mucopolysaccharidosis type IVB fibroblasts. We conclude that the ovine disease is due to a mutation at the genetic locus homologous with that of GM1 gangliosidosis and mucopolysaccharidosis type IVB, suggesting that the primary defect in the ovine disease is a mutation of the beta-galactosidase structural gene.
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PMID:Interspecific genetic complementation analysis of human and sheep fibroblasts with beta-galactosidase deficiency. 251 53

alpha-Galactosidase and beta-galactosidase activities have been determined in leukocyte preparations from 100 randomly selected Chinese adults. For alpha-galactosidase, two groups with low activities were identified: group I consisted of 3 females having activities below 40% of normal, and group II consisted of 5 males and 1 female with activities about 60% of normal. Family studies suggested that these low alpha-galactosidase activities are genetically determined. Only 1 individual was found to have about 50% of normal beta-galactosidase activity; presumably he is a carrier for beta-galactosidase deficiency (GM1 gangliosidosis).
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PMID:Lysosomal enzyme activities among Chinese: leukocyte alpha-galactosidase and beta-galactosidase. 283 34

This study was designed to establish an in vitro model with biochemical and morphological similarities to the human neurodegenerative disease GM1 gangliosidosis. Utilizing a specific inactivator of the lysosomal enzyme GM1-ganglioside beta-galactosidase (beta-D-galactopyranosylmethyl-p-nitrophenyltriazene [beta-GalMNT]) and neuroblastoma X glioma hybrid cells (NG108-15), we suppressed beta-galactosidase activity for up to 72 hours. Coincidental with suppression of this enzyme to levels less than 1% of control, we found up to a nine-fold accumulation of its substrate, the GM1-ganglioside, and the ultrastructural appearance of membranous cytoplasmic bodies. beta-GalMNT treatment suppressed growth but had little effect on the specific activity of choline acetyltransferase, lactate dehydrogenase, or other lysosomal enzymes including galactosylceramidase. This model should permit studies of the neurophysiological effects of increased ganglioside accumulation and their reversibility.
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PMID:Inactivation of GM1-ganglioside beta-galactosidase by a specific inhibitor: a model for ganglioside storage disease. 303 98

The uptake and degradation of GM1 ganglioside (GM1) and asialoGM1 ganglioside (GA1) were studied in cultured fibroblasts from normal individuals and patients with beta-galactosidase deficiency, using the lipid-loading test. The glycolipids were incorporated from the media into the fibroblasts and the terminal galactose was hydrolyzed in normal cells. The hydrolysis rates of GA1 were 80-86% of normal on the 3rd day after loading, while GM1 was hydrolyzed slowly; 35-54% on the 14th day. In infantile GM1 gangliosidosis and I-cell disease, little GM1 and GA1 was hydrolyzed on any day of culture, while fibroblasts from patients with adult GM1 gangliosidosis, Morquio disease type B and galactosialidosis hydrolyzed the lipids at nearly normal rates. The intracellular accumulation of the glycolipids, on the basis of protein content, was abnormally high in the case of infantile GM1 gangliosidosis and I-cell disease, but normal in the other disorders examined. These observations indicate that the in situ metabolism of GM1 and GA1 is probably normal in fibroblasts from patients with adult GM1 gangliosidosis, Morquio disease type B and galactosialidosis, although in vitro beta-galactosidase activities in these disorders are very low. The results are compatible with findings that GM1 and GA1 do not accumulate in the somatic organs of patients with adult GM1 gangliosidosis and galactosialidosis. In I-cell disease, however, the results of the loading test did not agree with the finding that there is little accumulation of glycolipids in postmortem tissues.
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PMID:Incorporation and degradation of GM1 ganglioside and asialoGM1 ganglioside in cultured fibroblasts from normal individuals and patients with beta-galactosidase deficiency. 307 39

Three adult patients in a single family showed severe myoclonus, ataxia, and pyramidal signs. Enzymatic analysis of lymphocytes, plasma, and cultured skin fibroblasts showed marked deficiency of beta-galactosidase activity, more profound with GM1 ganglioside than with another natural substrate, asialofetuin. Other lysosomal hydrolases were normal. Although the physical signs were similar to those of types 1 and 2 GM1 gangliosidosis, none had bony abnormalities.
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PMID:A family with beta-galactosidase deficiency: three adults with atypical clinical patterns. 307 94

Sphingolipid activator proteins (SAP) are relatively low-molecular-mass proteins that stimulate the hydrolysis of specific sphingolipids by the required lysosomal enzymes. SAP-1 or sulfatide/GM1 ganglioside activator protein has previously been demonstrated to stimulate the enzymatic hydrolysis of sulfatide, GM1 ganglioside and globotriaosylceramide. Using monospecific rabbit antibodies against human liver sulfatide/GM1 activator, the biosynthesis and processing of this activator were studied in cultured skin fibroblasts from controls and patients with GM1 gangliosidosis and a variant form of metachromatic leukodystrophy. When [35S]methionine was presented in the medium to control human fibroblasts for 4 h, the majority of the immunoprecipitable radiolabeling was confined to bands within three regions of apparent molecular mass 65-70, 35-52 and 8-13 kDa. The only immunoprecipitable radiolabeled species excreted into the medium when NH4Cl was present had an apparent molecular mass of 70 kDa. When the excretion products were given to fresh cells followed by incubation for up to 24 h there was production of the mature species. Treatment of the 70 kDa form with endoglycosidase F resulted in production of a 53 kDa molecular mass form. Pulse-chase experiments indicated that the initial immunoprecipitable translation product was 65 kDa which increased to 70 kDa over the next hour. The 65 kDa species must result from co-translational glycosylation of the polypeptide chain. Apparently, intralysosomal processing converts the 13 kDa form to the 8-11 kDa species. The cells from the patient with GM1 gangliosidosis could not process to the smallest species found in controls due to the deficiency of acid beta-galactosidase. Patients who have a variant form of metachromatic leukodystrophy do not make any immunoprecipitable radiolabeled products in the cells or in the media. This indicates a severe mutation in the gene coding for this activator protein. The production of such small mature species from a relatively large precursor form may regulate the production of this interesting protein.
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PMID:Biosynthesis of the sulfatide/GM1 activator protein (SAP-1) in control and mutant cultured skin fibroblasts. 308 Oct 38

The material derived from defective degradation of glycoproteins, which accumulates in brain and liver of a patient with GM1 gangliosidosis type I, was investigated, and the structure of the main storage compounds determined. For comparison, brain and liver of a patient with GM1 gangliosidosis type II were also analyzed. Analysis of the glycopeptides obtained after pronase digestion of the defatted residue indicates the storage of glycoprotein-like material in type I, but not in type II. Treatment with endo-beta-galactosidase showed that the stored material contained N-acetyllactosamine repeating units. Two major oligosaccharides, OS I and OS II, were isolated after the enzyme treatment, whose structures are: GlcNAc beta 1----3 Gal (OS I) and Gal beta l----4GlcNAc beta 1----3 Gal (OS II). Treatment with exo-beta-galactosidase transformed the trisaccharide OS II into the disaccharide OS I, indicating that the deficiency of beta-galactosidase in GM1 gangliosidosis type I, but not in type II, also affects glycoprotein catabolism, leading to the accumulation of glycopeptides containing terminal beta-galactosyl residues and N-acetyllactosamine repeating units. These results indicate the severe impairment in the catabolism of glycoconjugates with beta-linked galactose in type I, although this impairment is not as pronounced in type II.
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PMID:Presence of glycoproteins containing the polylactosamine structure in brain and liver of GM1 gangliosidosis patients. Comparative study between clinical types I and II, using endo-beta-galactosidase enzyme. 308 98

We studied beta-galactosidase in skin fibroblasts from patients with different forms of beta-galactosidase deficiency: adult GM1 gangliosidosis, type 1 GM1 gangliosidosis, and Morquio B syndrome. Enzyme properties in the adult cases differed from the other disorders and also from normal controls. Genetic hybridization studies indicated that all three forms belong to the same complementation group. Therefore, the adult disorder must be due to a mutation of the structural gene for beta-galactosidase, which is allelic to the mutations in type 1 GM1 gangliosidosis and Morquio B syndrome.
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PMID:Atypical adult GM1 gangliosidosis: biochemical comparison with other forms of primary beta-galactosidase deficiency. 309 33

The observation of generalized GM1 gangliosidosis type 1 (Norman-Landing disease) is reported. The case is typical, featuring all the main clinical and biological signs of the disease. Diagnosis was established by the demonstration of a severe deficit in beta-galactosidase activity in leucocytes, by the demonstration of oligosaccharides in the urine, and by the histological examination after the fatal outcome before the age of two with severe respiratory distress.
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PMID:[Gangliosidosis GM1--type 1. Anatomo-clinical study of a case]. 311 51

Enzymatic properties of beta-galactosidases with galactosylsphingosine (psychosine) and lactosylsphingosine as the substrates were examined. Although bile salts were stimulatory on the hydrolysis of the glycolipids in normal brain and cultured fibroblasts, the hydrolytic activities could be readily assayed, without detergents. The in vitro hydrolysis of lactosylsphingosine in cultured fibroblast homogenates was catalyzed by two enzymes, as is the case with the hydrolysis of galactosylceramide and lactosylceramide. Lactosylsphingosine beta-galactosidase activities assayed in the absence and the presence of taurocholate (probably lactosylceramidase I) were deficient in fibroblasts from patients with globoid cell leukodystrophy, while the activity assayed with sodium cholate (probably lactosylceramidase II) was deficient in GM1 gangliosidosis fibroblasts. In contrast, galactosylsphingosine beta-galactosidase was not activated by cholate and the enzyme activities assayed with the no-additive and taurocholate systems were deficient in brain and fibroblasts from patients with globoid cell leukodystrophy, thereby indicating that the hydrolysis of galactosylsphingosine is catalyzed by one enzyme, galactosylceramidase I. Exogenous lipids and an activator protein purified from normal spleen activated galactosylsphingosine beta-galactosidase but they were inhibitory to lactosylsphingosine beta-galactosidase. Because the Km values of lactosylsphingosine beta-galactosidase assayed with cholate were several magnitude higher than those obtained with the no-additive system and because lactosylsphingosine is readily hydrolyzed with the no-additive system in vitro, it is likely that the in vivo hydrolysis of the lipid is catalyzed by only one enzyme, lactosylceramidase I.
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PMID:Hydrolysis of galactosylsphingosine and lactosylsphingosine by beta-galactosidases in human brain and cultured fibroblasts. 311 43


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