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 existence of lysosomes and acid hydrolase activity was demonstrated in an in vitro blood-brain barrier (BBB) model comprising primary cultures of bovine brain microvessel endothelial cell (BMEC) monolayers. BMEC lysosomes were observed by the uptake of acridine orange and fluorophore-labeled acetylated low-density lipoprotein by fluorescence microscopy. Cytochemical localization of the acid hydrolase, sulfatase, and acid phosphatase (AcP) activities with light microscopy also revealed hydrolase-positive vacuoles or lysosomes that varied in number from cell to cell. BMEC monolayers were fractionated and biochemical assays of the sulfatase, AcP, and beta-galactosidase were performed. Significant activities of the acid hydrolases were found to be associated with lysosome and microsome fractions (69-77%). The majority of beta-galactosidase (approximately 48%) and total sulfatase (approximately 58%) activity was associated with the lysosome fraction of the BMECs. In contrast, approximately 52% of AcP activity was associated with the microsome fraction of the cells. The results of this study are consistent with the demonstration in vivo of acid hydrolases as potential factors in the endocytic pathway for transport of proteins through the BBB and as contributors to the BBB's enzymatic barrier function.
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PMID:Demonstration of acid hydrolase activity in primary cultures of bovine brain microvessel endothelium. 249 11

A circadian rhythm in acid phosphatase and hexosaminidase was found in adult male hamsters exposed to a long photoperiod (14:10 h light/dark [LD]; lights on 06.00 h) and killed at 08.00, 14.00, 20.00, 02.00, 04.00, 05.50 and 0.615 h. Hexosaminidase and beta-glucuronidase activity at 02.00, 04.00 and 05.50 h (values pooled for these times before lights on) were significantly elevated compared to enzyme activity at 06.15 and 08.00 h (pooled values after lights on), suggesting a fall in activity associated with lights on. Hypogonadism was induced in female Syrian hamsters by exposure to a short photoperiod (10:14 h LD) until a majority of them were vaginally acyclic. Pineal lysosomal enzyme activities (acid phosphatase, beta-glucuronidase, hexosaminidase, alpha-arabinosidase and beta-galactosidase) were significantly elevated in short photoperiod-exposed animals compared to animals in 14:10 LD, when measured near the middle of the light phase. In the third experiment, castrated animals were used to determine if lowered androgen levels might also affect pineal lysosomal enzyme activity. The results indicated that light phase beta-glucuronidase, hexosaminidase and beta-glucosidase activities were lower in castrated males compared to their intact controls. In summary, these results demonstrate that (1) lysosomal enzyme activity is present in the Syrian hamster pineal, (2) changes can be observed which suggest involvement of this activity in pineal function and, (3) a circadian rhythm in enzyme activity is present with peak activity occurring during the night. In the short photoperiod and castration experiments, the changes in lysosomal enzyme activity could reflect either a hormonal manipulation or a change in circadian regulation of enzyme activity.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Pineal lysosomal enzymes in the Syrian hamster: circadian rhythm and effects of castration or short photoperiod treatment. 252 45

To study the vesicular lysosome-associated transport and the metabolism of some brain macromolecules (in particular, sialoglycoconjugates), we developed a rapid procedure to obtain a distinct lysosomal population starting from myelinating mouse brain. This procedure is based on an initial differential centrifugation step producing a 1,000-17,500-g fraction (P2), followed by isopycnic centrifugation of fraction P2 on a self-generated colloidal silica gel (Percoll) gradient. The heaviest subfraction thus obtained is very rich in acid hydrolase activities like beta-galactosidase, arylsulfatase A, and acid phosphatase. The enrichment of these enzymes is approximately 100-fold as compared with the starting homogenate, whereas the markers of other subcellular organelles, such as mitochondria, plasma membranes, or the Golgi apparatus, are virtually absent. The lysosomal preparation contains approximately 12-14% of the total acid hydrolase activities, with a protein yield of approximately 0.12%. Electron microscopy shows that the lysosomal fraction is composed of an approximately 90% pure population of lysosomes. Therefore, the procedure described here is suitable for obtaining a highly purified lysosome preparation from myelinating mouse brain.
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PMID:Rapid preparation of a distinct lysosomal population from myelinating mouse brain using Percoll gradients. 254 49

Different enzymatic activities were studied in the human pancreatic cancer cell line CAPAN-1 in order to analyze their relation to differentiation. Alkaline phosphatase (Alk Ph), acid phosphatase, aminopeptidase, dipeptidyl peptidase IV, acid and neutral alpha-glucosidases, and acid beta-galactosidase were present. Especially alkaline phosphatase, which we have found to be of the placental type isoenzyme, is being highly expressed. Spontaneous cell differentiation at confluence as well as differentiating agents: sodium butyrate and DMSO, modulated the levels of three enzymes: Alk. Ph., aminopeptidase, and acid alpha-glucosidase. The exposure of the cells to the differentiating agents amplified the modulations occurring during the spontaneous differentiation. Aminopeptidase and acid alpha-glucosidase were found to be induced by differentiation. Alk Ph specific activity was significantly increased by the spontaneous and the butyrate-induced differentiations; whereas DMSO exerted an opposite effect, probably related to its biphasic action on cell proliferation.
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PMID:Modulation of enzymatic activities during spontaneous and induced differentiation in a human pancreatic adenocarcinoma cell line CAPAN-1. 254 14

Gamma-Glutamyl transpeptidase (gamma-GT) was studied histochemically and biochemically in the rat epididymis after castration with or without testosterone treatment, or after hemicastration and ligation of the efferent ducts. There was a strong reaction to gamma-GT in the apical part of the epithelium in the caput epididymis, while in the corpus and cauda the reaction was confined mainly to the luminal contents. Castration caused a marked decline in epithelial gamma-GT activity within 10 days. Subsequent testosterone treatment (1 mg/day for 10 days) restored gamma-GT activity in the apical surface and lumen. After hemicastration of adult rats, and after hemicastration or ligation of the efferent ducts in immature 28-day-old rats, a small but significant (P less than 0.001) decrease was observed in gamma-GT activity in the epididymal caput compared to controls. The quantities of six other enzymes (beta-N-acetylglucosaminidase, beta-galactosidase, angiotensin-converting enzyme, alanyl amino-peptidase, dipeptidyl peptidase IV, acid phosphatase) also displayed significant changes after castration and restoration of activities by testosterone treatment. However, their distribution in the caput and cauda epididymis was more even than that of gamma-GT, and the changes after castration were less drastic. It is concluded that gamma-GT is a highly sensitive androgen-dependent secretory marker in the caput epididymis and may have an important function in sperm maturation.
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PMID:Gamma-glutamyl transpeptidase in rat epididymis: effects of castration, hemicastration and efferent duct ligation. 257 65

Adler and Martin (1983, Curr. Eye Res. 2, 359-66) found cathepsin D to be present in crude preparations of bovine interphotoreceptor matrix (IPM). The purpose of the present study was to determine, by investigating several acid hydrolases in purer IPM samples, whether hydrolytic enzymes abundant in RPE lysosomes were present also as normal components of the IPM. IPM was prepared from bovine eyes by the introduction of a small bleb of buffer between the neural retina and the RPE. These IPM samples were free from significant contamination by surrounding tissues; they contained IRBP as their only major protein, and had negligible amounts of lactate dehydrogenase and ROS-specific proteins. Most acid hydrolases were assayed fluorometrically by measuring the 4-methylumbelliferone released upon hydrolysis of appropriate derivatives; the substrate for cathepsin was hemoglobin. The amounts of the enzymes found in the IPM were far from uniform and could not be correlated with enzyme activities in either RPE or retina homogenates. The hydrolases in the IPM varied in amount from beta-galactosidase (28% of the RPE level), through N-acetyl-beta-glucosaminidase (20%), alpha-fucosidase (15%), beta-glucuronidase (12%), alpha-glucosidase (8%), cathepsin D (7%), alpha-mannosidase (7%), down to beta-glucosidase, acid phosphatase, and acid lipase (trace amounts, less than 1%). These results agree with the relative amounts of enzymes found by Wilcox (1987) to be secreted into the medium by cultured human RPE cells. Furthermore, the rank order of hydrolases in the IPM is the same as that for hydrolases secreted (but not recaptured) by human fibroblasts in I-cell disease. The conclusion from these correlations is that lysosomal enzymes are probably secreted, as a normal process, by the RPE into the IPM, where they may have a role in digesting shed outer segments and in catabolizing IPM components.
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PMID:Selective presence of acid hydrolases in the interphotoreceptor matrix. 261 85

A method for rapid and effective extraction of rat liver lysosomal enzymes has been elaborated. It includes isolation of lysosomal-mitochondrial fraction by means of differential centrifugation, selective destruction of the lysosomal membrane by digitonin and centrifugal obtaining of the lysosomal matrix. Total labilization of the lysosomal membrane is achieved at 0.3 mM of the detergent. The maximal enrichment of an extract by lysosomal enzymes is observed in the range of 0.3-0.4 mM of digitonin. The level of lysosomal enzyme purification is 30.7 for cysteine cathepsins B, L, H, 24.9- for beta-galactosidase, 14.1- for acid phosphatase. The method gives high yield of lysosomal enzymes (40-80%).
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PMID:[Effective extraction of lysosomal enzymes with digitonin]. 272 13

In rats receiving a protein-poor diet for 60 days (4% caloric share of casein) the activity of beta-galactosidase, beta-N-acetyl glucose aminidase, acid proteinases, acid phosphatase, acetyl estherase, catalase, glutathione reductase, monoamine oxidase (MAO), glucose-6-phosphate dehydrogenase, and the content of malonic dialdehyde (MDA) were measured in the oral cavity mucosa. The authors observed the significant increase in MAO activity, and decrease in activities of beta-N-acetyl glucose aminidase, acetyl estherase, catalase, glutathione reductase, increased MDA contents. The changes in enzymatic activities had, to a several extent, an adaptive nature and were related to their reduced biosynthesis.
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PMID:[Enzymes of the oral mucosa in rats with protein deficiency]. 281 17

The structural gene for an acid phosphatase coded for by the gene appA of Escherichia coli K12 was cloned from a cosmid library into pBR322 and the restriction map determined. Several appA deletion plasmids and a smaller appA+ plasmid were constructed by in vitro recombination techniques and tested for their ability to complement an appA1 mutation. The appA gene was localized within a 2.1 kb segment. Its orientation was determined by construction of a hybrid plasmid carrying an appA-lacZ fusion. beta-galactosidase synthesized from the appA promoter was negatively regulated by cyclic AMP.
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PMID:Cloning and characterization of the pH 2.5 acid phosphatase gene, appA: cyclic AMP mediated negative regulation. 282 63

The substituted benzimidazole, omeprazole, is a potent inhibitor of the ATP-dependent proton pump of the parietal cell. Since there is accumulating evidence that hepatic lysosomes also possess an ATP-dependent proton pump system to maintain internal acidification, and since antibodies to the putative lysosomal proton pump protein are immunologically similar to the parietal cell (H+ + K+) ATPase, we studied the effects in rats of six days of omeprazole treatment on hepatic lysosomal function. Omeprazole, 5 mg kg-1, a dose five times the ED50 for gastric acid secretion inhibition in rats, did not alter the activity of three representative lysosomal enzymes in liver (acid phosphatase, beta-galactosidase and N-acetyl-beta-glucosaminidase) nor did it alter lysosomal enzyme latency, a measure of the integrity of the lysosomal membrane. Furthermore, bile flow and the secretion of lysosomal enzymes into bile were also unaffected by omeprazole. These data indicate that in rats short-term treatment with omeprazole, in doses that markedly inhibit gastric acid secretion, has no major biological effect on liver lysosomal integrity and lysosomal enzyme activity.
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PMID:Lack of effect of omeprazole, a potent inhibitor of gastric (H+ + K+) ATPase, on hepatic lysosomal integrity and enzyme activity. 287 Jan 66


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