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)

The effect of in vivo loading of the lysosomotropic agent 125I-Triton WR-1339 on the release of lysosomal enzymes in isolated perfused rat liver has been studied in the presence and absence of the microfilament poison cytochalasin B, as has the release of the 125I-Triton WR-1339 itself. Perfused isolated rat livers released all the enzymes studied (arylsulphatase, beta-galactosidase and lactate dehydrogenase) and, when preloaded, 125I-Triton WR-1339 was also released into the perfusate. The magnitude of the net release (after 5 hr perfusion) was in the order beta-galactosidase = 125I-Triton WR-1339 greater than lactate dehydrogenase greater than arylsulphatase. Preloading of the lysosomes with the detergent appeared to bring about an increase in the release of all the enzymes studied (3.5 X for beta-galactosidase, 2.6 X for arylsulphatase and 1.7 X for lactate dehydrogenase). The addition of the microfilament poison cytochalasin B into the perfusate of non-loaded livers significantly increased the release of the lysosomal enzymes but not that of lactate dehydrogenase. However in the 125I-Triton WR-1339- loaded livers cytochalasin B had no effect on the release of lysosomal enzymes or detergent, but reduced the loss of lactate dehydrogenase by about 50%. This failure of cytochalasin B to potentiate the exocytosis of lysosomal contents in 125I-Triton WR-1339-loaded livers is similar to the effect found previously with 125I-PVP-loaded livers and may be related to the already enhanced loss of lysosomal enzymes apparently caused by the loading.
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PMID:The release of intralysosomally-stored 125I-Triton WR-1339 and lysosomal enzymes from the isolated perfused rat liver in the presence and absence of cytochalasin B. 308 35

A 2.5-year-old girl who presented with abdominal distension, hepatomegaly, coarse facies, hirsutism and contraction deformities was investigated for mucopolysaccharidoses. Urinary excretion showed increased total glycosaminoglycans (105 mg/mmol creatinine; normal for age 9-20 mg/mmol) with marked increases of dermatan and heparan sulphates. A number of lysosomal enzyme activities were measured on leucocytes, serum and cultured fibroblasts. Normal or high activities were found for alpha-iduronidase, N-acetylgalactosamine-6-sulphatase, beta-galactosidase, arylsulphatase B and beta-glucuronidase. However a marked deficiency of iduronate sulphate sulphatase activity was observed, consistent with a diagnosis of Hunter's disease. Activities were reduced to less than 2% of mean control values in the patient's leucocytes, serum and cultured fibroblasts. Normal activities were measured in samples from the father and younger sister but a partial deficiency (43% of control serum) was found in the mother. Chromosome studies on the patient revealed a partial deletion of the long arm of one X-chromosome, most probably of band Xq25, which was not inherited from either parent. Studies using BrdU indicated that the deleted X chromosome was consistently late replicating, and as a result the Hunter gene was fully expressed on the other X chromosome.
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PMID:Full expression of Hunter's disease in a female with an X-chromosome deletion leading to non-random inactivation. 310 Jan 13

In Triton X-100 solubilized leukocytes of 17 patients and 8 obligate carriers of X-linked recessive ichthyosis (XLI) the activity of arylsulphatase C (ASC) was determined and expressed as the ratio to beta-galactosidase activity. The ASC/beta-gal ratio of XLI patients is markedly decreased (range 0.07-0.48) in comparison to the corresponding control group of males (range 1.3-2.7). The enzyme ratios of 8 obligate carriers of XLI are decreased (range 0.90-1.9) in comparison to the normal females (2.13-5.52). These results indicate that the determination of the enzyme ratio of ASC/beta-gal in Triton X-100 solubilized leukocytes is a sensitive test for biochemical identification of patients and probably of carriers of XLI.
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PMID:Arylsulphatase C activity in leukocytes of patients and carriers of X-linked ichthyosis. 310 20

In this paper circadian changes in the liver enzyme activities of rat housed under highly standardized conditions with 12: 12 hour light-dark cycle are shown. Activities of acid phosphatase, arylsulphatase, beta-galactosidase and beta-N-acetyl-D-glucosaminidase in microsomal and lysosomal fractions and crude homogenate were estimated every 4 hr during one 24-hr period. The enzyme activities were related to 1 mg of protein, 1 mg of DNA and 1 g fresh tissue. Daily changes of enzyme activities were found. In case of activity calculated per 1 mg DNA two maxima at 0500 and at 2100 hr were observed, while activity calculated per 1 mg protein showed one maximum at 0500 hr. Activity calculated per 1 g fresh tissue showed the maximum at 0500 hr for each enzyme only in microsomal fraction. As far as acrophase table is concerned for all enzymes and fractions the acrophase occurred during the night. The obtained results are discussed in relation to lysosomal enzymes synthesis process as well as different reference values.
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PMID:Temporal changes of acid phosphatase, arylsulphatase, beta-galactosidase and beta-N-acetyl-D-glucosaminidase activities in subcellular fractions of rat liver. 311 33

Electron inactivation analysis with 16 MeV electrons was used to determine the functional target size of a number of commonly studied lysosomal hydrolases. Observed values ranged from a low of 62 000 +/- 4000 Da for beta-galactosidase to a high of 200 000 +/- 17 500 Da (mouse beta-glucuronidase). One group of lysosomal hydrolases (N-acetyl-beta-glucosaminidase, N-acetyl-beta-galactosaminidase, alpha-galactosidase, beta-mannosidase, beta-glucosidase, arylsulphatase A and sphingomyelinase) had target sizes in the range 100 000-120 000 Da, whereas alpha-glucosidase and alpha-fucosidase exist as complex multimers in the 150 000-160 000 Da range. Analysis of freeze-dried cell material showed little evidence of species (mouse versus human) variation in the functional size of most lysosomal hydrolases with the exception of beta-glucuronidase. Our findings suggest the potential usefulness of lysosomal hydrolases as endogenous marker enzymes in studies where the target size of proteins of unknown molecular mass is to be determined.
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PMID:Functional lysosomal hydrolase size as determined by radiation inactivation analysis. 315 87

beta-Galactosidase activity but not beta-glucuronidase, N-acetyl-beta-D-galactosaminidase or arylsulphatase A activity, is known to be significantly lower in cultured human skin fibroblasts from patients with cystinosis than in cells from control subjects. Incubation of cell homogenates with disulphide or thiol compounds did not affect beta-galactosidase activity, suggesting that decreased beta-galactosidase activity in affected cells was not caused by the presence of inhibiting substances or absence of activating substances. Incubating cells with 0.5 or 1.0 mmol/l cysteamine, a substance used in the clinical treatment of cystinosis because it depletes cells of excess cystine, greatly decreased beta-galactosidase activity in both cystinotic and normal cells. This effect is shown to result from enzyme instability in lysosomes with raised pH and increased thiol concentration. Thus, cysteamine, although effective in depleting cystinotic cells of excess cystine, may have the undesired side-effect of severely decreasing lysosomal beta-galactosidase.
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PMID:A study of the low beta-galactosidase activity in cystinotic fibroblasts: effects of cysteamine. 391 71

Antisera were raised to a partially purified preparation of human liver hexosaminidase and to highly purified preparations of hexosaminidase isoenzymes A and B. All the antisera precipitated the enzyme in an enzymically active form, which could be located on immunodiffusion and immunoelectrophoretic gels by using a histochemical substrate. The antisera to the purified isoenzymes were shown to react with hexosaminidase from human liver, kidney, brain and spleen, but did not cross-react with human liver beta-glucosidase, beta-galactosidase, alpha-mannosidase, beta-xylosidase, arylsulphatase or acid phosphatase. Hexosaminidases A and B were immunologically identical. The immunological properties of the hexosaminidases from livers of patients with three types of GM(2)-gangliosidoses were closely similar. No evidence could be found for cross-reacting material in enzyme-deficient states.
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PMID:Immunological properties of N-acetyl-beta-D-glucosaminidase of normal human liver and of GM2-gangliosidosis liver. 419 85

1. The following fractions were prepared from rat kidney and characterized ultrastructurally, biochemically and enzymically: (a) an ordinary rough microsomal (RM(1)) fraction; (b) a special rough microsomal (RM(2)) fraction enriched seven- to nine-fold in acid hydrolases over the homogenate; (c) a smooth microsomal (SM) fraction; (d) a Golgi (GM) fraction enriched 2.5-fold in acid hydrolases and 10-, 15- and 20-fold in sialyltransferase, N-acetyl-lactosamine synthetase and galactosyltransferase respectively; (e) a lysosomal (L) fraction enriched 15- to 23-fold in acid hydrolases. The frequency of Golgi sacs and tubules seen in the electron microscope and the specific activity of the three glycosyltransferases in these fractions increased in the order: RM(2)<RM(1)<SM<GM. 2. Five lysosomal hydrolases, acid phosphatase, beta-N-acetyl-hexosaminidase, beta-galactosidase, beta-glucuronidase and arylsulphatase, were characterized in these fractions with respect to (a) solubility on freeze-thawing and (b) electrophoretic mobility in polyacrylamide gels. 3. In the RM(2) fraction each of these hydrolases occurred largely or exclusively as a single bound basic form coincident with cationic glycoprotein bands in gels (Goldstone et al., 1973). 4. In the L fraction these hydrolases were present largely as soluble, acidic (anionic) forms. 5. The solubility, electrophoretic heterogeneity and anodic mobility of these hydrolases increased progressively in subcellular fractions in the order: RM(2)<RM(1)<SM<GM<L. 6. These findings, together with evidence cited in the text showing that N-acetylneuraminic acid residues are responsible for the solubility and electronegative charge of these acidic forms and incorporation of these residues into the Golgi apparatus, support the following scheme for the biosynthesis of lysosomal enzymes. Each hydrolase is synthesized as a bound basic glycoprotein enzyme in a restricted portion of the rough endoplasmic reticulum. The soluble, acidic forms are generated as the nascent glycoprotein enzymes migrate through the Golgi apparatus through the attachment of sugar sequences containing N-acetylneuraminic acid.
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PMID:Physicochemical modifications of lysosomal hydrolases during intracellular transport. 472 40

1. Chicken brain arylsulphatase A was purified 2000-fold, with overall recovery 14%, by using ammonium sulphate fractionation, ethanol precipitation, Sephadex G-200 gel filtration and DEAE-Sephadex column chromatography. 2. The purified preparation was free from beta-glucuronidase, beta-galactosidase, acid phosphatase, inorganic pyrophosphatase and adenosine 3'-phosphate 5'-sulphatophosphate sulphohydrolase activities. 3. Polyacrylamide-gel electrophoresis indicated that the purified preparation was not homogeneous. 4. Chicken brain arylsulphatase was markedly inhibited by carbonyl reagents in the presence of traces of Cu(2+) in the system. Other metal ions such as Fe(2+) and Zn(2+), were inactive. 5. Ascorbic acid alone had no effect on enzyme activity but enhances the inhibition by Cu(2+). 6. Chicken brain arylsulphatase A resembled arylsulphatase A of other animal species in its kinetic properties such as K(m) value, anomalous time-activity relationship and the inhibitory effect of phosphate, sulphite and sulphate ions. However, its electrophoretic mobility, behaviour under zinc acetate fractionation and stimulation by Ag(+) were similar to arylsulphatase B of other animal species. Thus, this enzyme did not correspond to either arylsulphatase A or arylsulphatase B but properties of both. 7. The purified enzyme preparation can degrade cerebroside 3-sulphate.
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PMID:Purification and properties of arylsulphatase A from chicken brain. 507 33

Changes of activity of intestinal acid beta-galactosidase, beta-glucuronidase, N-acetyl-beta-glucosaminidase and arylsulphatase were studied in suckling rats treated with cortisone (5mg/100g body wt. daily, started on day 9 postnatally) and compared with changes in control animals. Specific activities were not changed within the first 72h, but all enzymes decreased similarly 96h after the first injection. Total activities per ileum and animal were not changed within the first 48h, but within 72h a significant decrease was observed. Calculation of the rate of decrease of the hydrolases studied in cortisone-treated animals shows that it proceeds faster than the rate of renewal of enterocytes in this period.
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PMID:Cortisone-evoked decrease of acid -galactosidase, -glucuronidase, N-acetyl- -glucosaminidase and arylsulphatase in the ileum of suckling rats. 514 82


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