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)

The sex and age dependence of activity of eight glycosidases and acid phosphatase was assayed in serum samples using the 4-methylumbelliferyl substrates. The activity of these enzymes does not change in relation to sex and to age except for acid phosphatase and beta-galactosidase which show significantly higher values in children as compared to adults. The usefulness of the 4-MU substrates for the detection of homozygotes for those lysosomal diseases involving one of the glycosidases studied is discussed.
Clin Chim Acta 1978 Dec 01
PMID:Study of influence of sex and age on human serum lysosomal enzymes by using 4-methylumbelliferyl substrates. 71 94

Comparison of growth rates of isogenic strains that synthesize varying levels of beta-galactosidase during continuous culture on non-inducing medium indicates that synthesis of low levels of non-functional protein has a small but possibly significant effect upon growth rate.
J Mol Evol 1976 Dec 30
PMID:Selective disadvantage of non-functional protein synthesis in Escherichia coli. 79 67

The effect of bile salts on the hydrolysis of lactosylcermide by human beta-galactosidases in vitro was studied using cultured skin fibroblasts, liver and brain tissue. The evidence for two distinct enzymes that can catalyze the hydrolysis of lactosylceramide was observed when the bile salt was changed from pure sodium taurocholate to either crude taurocholate, or pure glycodeoxycholate, taurodeoxycholate or taurochenodeoxycholate. Tissues from patients with Krabbe's disease were found to be deficient in lactosylceramide beta-galactosidase activity (lactosylceramidase I) when pure taurocholate was used in the assay. When crude taurocholate was used in the assay, the Krabbe patients appeared to have normal activity for this enzyme. In place of crude taurocholate the pure salts of glycodeoxycholate, taurodeoxycholate and taurochenodeoxycholate worked even better to stimulate the second lactosylceramide beta-galactosidase activity and GM1 gangliosidosis patients exhibiting little if any activity. Therefore, lactosylcermidase I is stimulated by crude taurocholate or pure glycodeoxycholate, taurodeoxycholate and taurochenodeoxycholate. The use of pure bile salts to assay lactosylceramidase I and II will result in better reproducibility for these enzyme activities between laboratories.
Biochim Biophys Acta 1975 Dec 17
PMID:Effect of bile salts on lactosylceramide beta-galactosidase activities in human brain, liver and cultured skin fibroblasts. 81 51

Clinical, histological, ultrastructural and biochemical studies have been performed in a living 20-month-old infant with GM1-gangliosidosis type 2. Rectum, brain and liver biopsies were done. The histological and ultrastructural examination revealed the presence of cytoplasmic membranous bodies in the nervous system and a vacuolisation of the visceral parenchymatous cells, particularly histiocytes. The diagnosis was established by the finding of a generalized beta-galactosidase deficiency and an accumulation of GM1-ganglioside in brain. In leukocytes, the activity of p-nitrophenyl-beta-galactosidase was below 5%, and that of GM1-ganglioside beta-galactosidase below 1% of values obtained in controls. In cerebral tissue, GM1 ganglioside constituted 80% of total gangliosides; its concentration was 15 times that in age-matched controls. No accumulation of GM1 could be evidence in liver. Enzymatic examination of leukocytes obtained from the consanguineous parents revealed heterozygote values.
Arch Fr Pediatr 1975 Dec
PMID:[Clinical, ultrastructural and biochemical study of a case of GM1 type 2 gangliosidosis]. 82 51

Very complex glycosphingolipids with A, H and I blood-group activities were isolated from human erythrocyte membranes. The membranes were obtained from erythrocytes of blood group A, A2 and O respectively. A general formula for the antigens is: (Fuc)3-4(Gal)n(LlcNAc)n-2(Glc)1(Sphingosine)1(where Fus is fucose, Gal is galactose, GlcNAc is N-acetylglucosamine and Glc is glucose) with values of n ranging from 10-27. A-active preparations contain additionally 2-3 residues of N-acetylgalactosamine. In view of the unusual complexity of these compounds they were designated poly(glycosyl)ceramides (formerly megaloglycolipids). Individual poly(glycosyl)ceramide fractions were isolated from A erythrocytes and were found to differ by about 8 glycosyl residues per molecule forming a series of compounds with 22, 30, 38, 51 and 59 glycosyl residues per mole. Structural studies indicate that the main sequence of poly(glycosyl)ceramides consists of the residues of galactopyranose and 2-deoxy-2-acetamidoglucopyranose substituted at 3 and 4 position respectively. These residues are probably alternating. N-Acdtylglucosamine substituted at 3 position was not found in poly(glycosyl)ceramides. Brances of poly(glycosyl)ceramides originate from 3 and 6 position of galactopyranosyl residues. The number of branches is proportional to the degree of molecular complexity. In poly(glycosyl)ceramides isolated from A and A2 erythrocytes the branches are terminated with the following structures GalNAc alpha 1 leads to 3 [Fuc alpha 1 leads to 2] Gal; Fuc alpha 1 leads to 2 Gal and Gal (presumably Gal beta 1 leads to 4 GlcNAc). In poly(glycosyl)ceramides from A cells the total number of A and H-active structures per average molecule of 30-35 glycosyl residues amounts to 2.1 and 1.2 respectively while the number of terminal galactose structures is 1.8. For poly(glycosyl)ceramides from A2 erythrocytes the corresponding figures are 0.75, 3.5, and 2.1 respectively. Poly(glycosyl)ceramides from O cells comprise about 3.8 H-active structures and 1.8 terminal galactopyranosyl residues. In poly(glycosyl)ceramides with high "n" values the number of terminal galactose structures is increased. These fractions display high blood-group I activity. However, the removal of terminal galactose with beta-galactosidase affects I-activity only slightly.
Eur J Biochem 1976 Dec
PMID:Isolation and characterization of poly(glycosyl)ceramides (megaloglycolipids) with A, H and I blood-group activities. 82 47

The Bgs locus determines tissue levels of beta-galactosidase in the mouse, so that enzyme levels are twice as high in mice carrying the Bgsh allele as in mice carrying the Bgsd allele (Felton et al., 1974). By immunotitration with antiserum to purified beta-galactosidase, we have found that the Bgs locus influences the amount of enzyme protein present in the tissues. We have utilized recombinant inbred lines derived from a cross between C57BL/6J and DBA/2J mice to confirm the location of the Bgs locus on chromosome 9. The inhibition of mouse beta-galactosidase by the active-site-directed reagent N-bromoacetyl-beta-D-galactosylamine has been investigated. beta-Galactosidase from the high and low Bgs strains has identical affinity for this inhibitor.
Biochem Genet 1976 Dec
PMID:Effects of the Bgs locus on mouse beta-galactosidase. 82 52

The developmental program for beta-galactosidase in C57BL/6J and related strains of mice differs from that seen in most other mouse strains. Mice of the C57BL/6 group show a rise in liver enzyme activity during development that is not seen in mice of other strains. The developmental pattern of beta-galactosidase activity in heart and brain of C57BL/6 mice is similar to that in other strains. Physical, kinetic, and immunological tests indicate that the developmental increase in C57BL/6 enzyme activity is an increase in the number of molecules of the same species of enzyme protein that is present in other strains. In genetic crosses, the presence of the developmental rise in liver enzyme activity segregates as if determined by a single genetic factor showing additive expression in heterozygotes. This factor is closely linked to the beta-galactosidase structural gene on chromosome 9. The existence of a genetic variant with these properties is evidence that programmatic information capable of regulating the temporal expression of a structural gene can be encoded in DNA.
Cell 1976 Dec
PMID:Genetic determination of the beta-galactosidase developmental program in mouse liver. 100 75

Two closely linked regulatory genes have been reported to control activity levels of beta-galactosidases in murine tissues. The specific effects of these genes on murine glycolipid metabolism have not been elucidated. A/HeJ kidney 4-methylumbelliferyl-beta-galactosidase exhibited lower thermostability than the corresponding C57BL/6J and SWR/J enzymes. This altered response to heat segregated with the Bgsh allele among progeny derived from backcrosses of F1 (A/HeJ; SWR/J) mice to the respective parental strains. Restriction of the heat-sensitive A/HeJ beta-galactosidase to kidney tissue suggests that it is not determined by the Bgs locus, since the latter appears to be expressed in all tissues. More likely, the Bgs region of chromosome 9 contains a gene cluster consisting of a number of regulatory and structural loci. The proposed structural genes share affinity for the artificial substrates commonly employed for their assay but may differ in their relative affinities for glycosphingolipid substrates. Presence of the Bgsh allele results in an increase of kidney GM1-ganglioside-beta-galactosidase; however, galactosylceramide-beta-galactosidase appears unaffected by this allele.
Biochem Genet 1976 Dec
PMID:Correlation between structural variation and activity of murine kidney beta-galactosidase: implications for genetic control. 101 27

The latency of the alpha-glucosidase activity of intact rat liver lysosomes was studied by using four substrates (glycogen, maltose, p-nitrophenyl, alpha-glucoside, alpha-fluoroglucoside) at a range of substrate concentrations. The results indicate that the entire lysosome population is impermeable to glycogen and maltose, but a proportion of lysosomes are permeable to alpha-fluoroglucoside and a still higher proportion permeable to p-nitrophenyl alpha-glucoside. Incubation at 37 degrees C in an osmotically protected buffer of of pH 5.0 caused lysosomes to become permeable to previously impermeant substrates and ultimately to release their alpha-glucosidase into the medium. The latencies of lysosomal beta-glucosidase and beta-galactosidase were examined by using p-nitrophenyl beta-glucoside and beta-galactoside as substrates. The results indicate permeability properties to these substrates similar to that to p-nitrophenyl alpha-glucoside. On incubation in an osmotically protected buffer of pH 5, lysosomes progressively released their beta-galactosidase in soluble form, but beta-glucosidase remained attached to sedimentable material. Lysosomal beta-glucosidase was inhibited by 0.1% Triton X-100; alpha-glucosidase and beta-galactosidase were not inhibited.
Biochem J 1976 Dec 15
PMID:Latency of some glycosidases of rat liver lysosomes. 101 43

N-Acetyl-beta-glucosaminidase, beta-galactosidase, beta-glucosidase, acid and alkaline phosphatase were monitored in urine kidney homogenates and serum of rats with papillary damage induced with ethyleneimine. Serum urea levels, total protein in the urine and urine volume were monitored throughout the study. Histological studies showed that the injection of ethyleneimine caused immediate papillary necrosis, followed later by secondary cortical involvement. Minor papillary necrosis induced by a low dose (0.5 mul/kg) of ethyleneimine was characterised by a rise in urinary N-acetyl-beta-glucosaminidase activity which was followed later by an increase in the activity of the other enzymes monitored. More severe papillary necrosis induced with a higher dose of ethyleneimine (5.0 mul/kg) resulted in an immediate rise in the activities of all the urinary enzymes which then decreased only to rise again when cortical involvement occurred. Serum urea was unaltered but urine volume and protein were increased coincidentally with the urinary enzyme activities. The value of the assay of urinary enzymes in distinguishing papillary from glomerular and tubular damage is assessed. The possible relevance of the ethyleneimine model to the etiology of papillary nephropathy is discussed.
Chem Biol Interact 1975 Dec
PMID:Urinary enzyme excretion during renal papillary necrosis induced in rats with ethyleneimine. 120 12


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