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 specific activity of 4 lysosomal enzymes was studied in homogenate, hepatocytes, Kupffer and endothelial cells isolated from the livers of female Sprague-Dawley rats aged 3.5, 12 and 24 months. Cells were obtained by enzymatic digestion and centrifugal elutriation. Cell viability was not affected by age or diet. In hepatocytes, the activities of all enzymes (acid phosphatase, beta-galactosidase, arylsulfatase B and cathepsin D) increased with age in rats fed ad libitum (A) but were not altered significantly by dietary restriction. The activities of all enzymes except acid phosphatase were systematically higher at 3.5 months of age in Kupffer and endothelial cells than in hepatocytes. Acid phosphatase, arylsulfatase B and cathepsin D activities increased with age in both Kupffer and endothelial cells. Beta galactosidase was decreased significantly with age in Kupffer cells but was elevated in endothelial cells. Rats exposed to dietary restriction (R) showed higher activities of beta-galactosidase, arylsulfatase B and cathepsin D when compared to corresponding A animals with the exception of the younger age group. No clear cut pattern was observed in acid phosphatase activity. Thus, the activities of liver lysosomal enzymes increase with age but the pattern of change differs with respect to enzyme and cell populations. The heightened enzyme activity in Kupffer and endothelial cells from R rats may reflect a more efficient phagocytic capacity in these animals.
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PMID:Characterization of liver lysosomal enzyme activity in hepatocytes, Kupffer and endothelial cells during aging: effect of dietary restriction. 229 Mar 53

Extracts of the pathogenic ameba Naegleria fowleri, prepared by freeze-thawing and sonication, were analyzed for their content of various hydrolytic enzymes that have acid pH optima. The organism is rich in acid phosphatase activity as well as a variety of glycosidases which include beta-glucosidase, beta-galactosidase, beta-fucosidase, alpha-mannosidase, hexosaminidase, arylsulfatase A, and beta-glucuronidase. The crude extract contained only negligible levels of sphingomyelinase, neuraminidase, or arylsulfatase B. All of the hydrolases exhibited higher activity at pH 5.5 than at 7.0, indicating that they are truly "acid" hydrolases. In general, after centrifugation (100,000 g, 1 h), except for arylsulfatase B, more than half of the activity of each of the various hydrolases was recovered in the supernatant fraction. The acid phosphatase in the high-speed supernatant was purified 45-fold (32% yield) by chromatography on QAE-Sephadex and Sephadex G-200 and shown to have the following properties: pH optima, 5.5; Km (4-methylumbelliferyl phosphate), 0.60 mM; molecular weight (estimated by gel filtration chromatography), 92,000; inhibited by heteropolymolybdate complexes but not by L(+) sodium tartrate (0.5 mM) or sodium fluoride (0.5 mM). In addition, unlike the tartrate-resistant acid phosphatase of Leishmania donovani, the major acid phosphatase of N. fowleri is less than 5% as effective in inhibiting superoxide anion production by f-Met-Leu-Phe-stimulated human neutrophils. The finding of high levels of a number of acid hydrolases in Naegleria fowleri raises several questions that merit further study: Do the hydrolases perform a housekeeping function in this single cell eukaryote or do they play some role in the pathogenic process that ensues when the organism infects a suitable host?
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PMID:Demonstration of various acid hydrolases and preliminary characterization of acid phosphatase in Naegleria fowleri. 301 38

Fibroblasts cultured from the skin of a patient with metachromatic leukodystrophy have been found to manifest the biochemical defect of this inborn error of metabolism, a deficiency of arylsulfatase A. Diseased cells had less than five per cent of normal arylsulfatase-A activity, while activities of other lysosomal enzymes-including arylsulfatase B, beta-galactosidase, beta-glucuronidase, and beta-N-acetylglucosaminidase-were comparable to those in control cells. The presence of dissociable inhibitors in extracts of the diseased cells was excluded by combination experiments. The deficiency of the enzyme in leukocytes was also confirmed and is comparable to that found in cultured fibroblasts. The finding that readily cultured fibroblasts from easily obtained skin biopsy specimens exhibit the enzymatic defect should prove valuable in the biochemical study of this disease.
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PMID:Metachromatic leukodystrophy: arylsulfatase-A deficiency in skin fibroblast cultures. 525 10

During fasting of animals, there is decreased content of skin glycosaminoglycans (GAGs) accompanied by decrease in their biosynthesis. Since tissue GAG content depends on both synthesis and degradation of these molecules, we asked whether fasting affects the activity of several tissue glycosidases. Therefore we measured the activity of skin neutral and acidic endoglycosidases, some exoglycosidases: beta-N-acetylhexosaminidase [EC 3.2.1.30], beta-galactosidase [EC 2.1.23], beta-glucuronidase [EC 3.2.1.31], alpha-iduronidase [EC 3.2.1.76], and two sulfatases: arylsulfatase B [EC 3.1.6.1] and 6-sulfatase [EC 3.1.6.14] in the skin of control and fasted rats. Although fasting was accompanied by distinct decrease in the activity of most neutral endoglycosidases, no characteristic changes in the activity of exoglycosidases were found. In contrast, we found that fasting is associated with increase in the activity of acidic endoglycosidases (of lysosomal origin) which degraded hyaluronic acid, chondroitin-4-sulfate, chondroitin-6-sulfate and heparin. The same GAGs were decreased in the skin of fasted rats. Our data suggest that the phenomenon is a result of increased intracellular degradation of these molecules. Therefore, not only decreased biosynthesis of GAGs during fasting, but also increased their intracellular degradation may contribute to decrease in GAG skin content.
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PMID:Glycosaminoglycan-degrading enzymes in the skin of fasted rats. 1195 38