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 following enzymes of lysosomal origin were fluorimetrically determined in maternal plasma from the second to the ninth month of pregnancy at 1-mth intervals: beta-D-N-acetylglucosaminidase (EC 3.2.1.30), beta-D-glucuronidase (EC 3.2.1.31), beta-D-glucosidase (EC 3.2.1.21), beta-D-galactosidase (EC 3.2.1.22), alpha-D-galactosidase (EC 3.2.1.23), alpha-L-fucosidase (EC 3.2.1.51) and alpha-D-mannosidase (EC 3.2.1.24) (pH 4.0). As reference microsomal alpha-D-mannosidase (pH 5.7) was also studied. Thirty-eight healthy women, aged 18-37 yr, who had a normal pregnancy followed by normal parturition, were studied. All enzymes, with the only exception of beta-D-galactosidase, showed a progressive and statistically significant increase of activity throughout pregnancy. At the end of pregnancy, the increase ranged from a maximum of 5.6-fold for beta-D-N-acetylglucosaminidase to a minimum of 0.55-fold for alpha-D-mannosidase, pH 5.7. In the case of beta-D-N-acetylglucosaminidase, the level at the fifth month of pregnancy was significantly higher than that at the third month, and from the sixth to the ninth month each level significantly differed from that of the month immediately preceding.
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PMID:Behaviour of several enzymes of lysosomal origin in human plasma during pregnancy. 609 42

In this communication results are presented of an investigation in which the activity of the hydrolytic enzymes acid phosphatase, beta-glucuronidase, non specific arylesterase, microsomal arylsulphatase, beta-galactosidase, beta-N-acetylglucosaminidase, acid alpha-glucosidase and aminopeptidase M are demonstrated in tissue sections with simultaneous- and post-coupling azo-techniques. Semipermeable membrane techniques are used to hamper enzyme diffusion during the incubation period. From the histochemical and biochemical findings it appeared that an advantage of the post-coupling techniques over the simultaneous-coupling techniques is that inactivation of the enzymes by the coupling reagents is avoided. On the other hand post-coupling techniques are subject to product inhibition. With kinetic inhibition studies it is found that for microsomal arylsulphatase and non-specific arylesterase this product inhibition is non-competitive. This product inhibition may be a problem for histochemical quantitative post-coupling techniques for the determination of acid hydrolase activity.
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PMID:Diazonium inactivation in simultaneous-coupling and product inhibition in post-coupling azo-techniques for demonstrating activity of acid hydrolases. 620 67

Lungs were obtained from rabbit fetuses (on each day from d 24 to d 30 of gestation), neonates and adults, and were fractionated for enzyme assays. The developmental profile of cytidylyltransferase shows a decrease in specific activity from d 25 to d 29 (P less than 0.05) then a sharp rise from d 30 to adult values in d 0 neonates (P less than 0.05). Cholinephosphotransferase specific activity changes little from d 25 to birth, apart from a non-significant peak on d 29. There is a sharp rise from neonatal d 0 to adult values on d 1 (P less than 0.01). The specific activity of microsomal phospholipase A2 declines from d 25 to reach adult values in the neonate (P = 0.05). In contrast, the specific activity of lysosomal phospholipase A2 rises from d 24-28 then falls in the neonate (P less than 0.05). Adult values are higher than those in the fetus and neonate. Three other lysosomal enzyme specific activities rise to d 28 then decline: phospholipase A1, beta-galactosidase, and beta-glucuronidase. The results demonstrate that the level of microsomal phospholipase A2 does not control the extent of remodelling of phosphatidylcholine for surfactant production. Lysosomal phospholipase A2 only increases in parallel with the other lysosomal enzymes, indicating an increase in the number of lysosomes in the lung.
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PMID:Developmental changes in enzyme activities in fetal and neonatal rabbit lung. Cytidylyltransferase, cholinephosphotransferase, phospholipases A1 and A2, beta-galactosidase, and beta-glucuronidase. 632 5

Porcine adrenocortical lysosomes were characterized by differential centrifugation, acid hydrolase contents, latency of cathepsin D, release of bound acid hydrolases in soluble form, and isopycnic density gradient centrifugation. Cathepsins D and B, beta-N-acetylglucosaminidase, beta-galactosidase and arylsulphatase were found exclusively in the lysosomes, while alpha-mannosidase and beta-glucuronidase were in both the lysosomal and microsomal fractions. The activity of cathepsin D was remarkably high, amounting to more than 6 times that in porcine liver and to more than 10 times that in liver of Sprague-Dawley rats in terms of units per g wet tissue. Porcine adrenocortical lysosomes showed a modal isopycnic density value of 1.155, but mitochondria a value of 1.145. The validity of these values was studied by investigating the possibilities of agglutination of organelles, damage to lysosomal membranes, disruption of mitochondria due to the hydrostatic pressure and by applying the same procedures of isopycnic centrifugation to hog and rat livers. After these validity tests, porcine adrenocortical lysosomes were concluded to be unique in their strikingly high content of cathepsin D as well as in their low modal isopycnic density which is very close to that of porcine adrenocortical mitochondria.
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PMID:Characterization of porcine adrenocortical lysosomes. 679 90

Phosphatidate phosphohydrolase (PAPase) activity was measured in lamellar bodies purified from porcine lung tissue. After repeated freeze-thawing, only a negligible amount of PAPase activity was released into the soluble fractions, whereas there was release of 2 lysosomal marker enzyme activities, glucosaminidase and beta-galactosidase into the soluble fraction. In addition, a lysosomal-enriched fraction was prepared from adult rat lung tissue by prior treatment of the rats with Triton WR 1339. Treatment with Triton WR 1339 resulted in the significant shift of the activities of the lysosomal marker enzymes, glucosaminidase and beta-galactosidase, to less dense subcellular fractions. The highest specific activity of PAPase was found in a subcellular fraction which had a density that was intermediate between that of the mitochondrial and microsomal fractions and the distribution of PAPase activity was not affected by the prior treatment of the rats with Triton WR 1339.
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PMID:Distribution of the phosphatidate phosphohydrolase activity in the lamellar body and lysosomal fractions of lung tissue. 740 42

The amounts of lactase (EC 3.2.1.23), sucrase (EC 3.2.1.48), maltase (EC 3.2.1.20), microvillus aminopeptidase (microsomal EC3.4.11.2), and dipeptidyl peptidase IV (EC 3.4.14.X) in biopsies from proximal jejunum and distal ileum were studied by quantitative crossed immunoelectrophoresis and enzymatic assays in obese patients one and six months after jejunoileal bypass operation and compared with peroperative levels. They were related to DNA and protein content. The protein/DNA ratio fell 28-43% postoperatively. Except for ileal lactase and sucrase all enzymes showed decreased levels when expressed per mg protein and an even more pronounced decrease when related to DNA. Lactase and sucrase levels in ileum were increased or unchanged. A constant correlation between the amount of immunoreactive enzyme protein and enzymatic activity was shown for all enzymes except maltase. The results suggest that the bypass operation is followed by an increased amount of enterocytes devoid of or low in enzymatic activity and protein content. The amounts of lactase and sucrase in ileum are increased in relation to the other enzymes. No immunoreactive enzymes with zero or depressed activity were detected.
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PMID:Immunoelectrophoretic studies on human small intestinal brush border proteins: cellular alterations in the levels of brush border enzymes after jejunoileal bypass operation. 742 30

The action of non-detergent sulphobetaines (NDSBs) as new mild agents for protein purification is described. The solubilization effects of non-detergent sulphobetaines are shown in different examples; all obtained under non-denaturing conditions: (1) microsomal proteins extraction; (2) recovery after dialysis of nuclear proteins; (3) reduction of precipitation in isoelectric focusing experiments under non-denaturing conditions; and (4) purification of a membrane-bound serine protease from Plasmodium falciparum involved in erythrocyte invasion by malaria merozoites. The absence of a significant denaturation effect induced by NDSBs is demonstrated by tests on beta-galactosidase and alkaline phosphatase. A simple NDSB synthesis and some possible explanations of the action of NDSBs are also presented.
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PMID:Non-detergent sulphobetaines: a new class of mild solubilization agents for protein purification. 782 51

Rat microsomal aldehyde dehydrogenase (msALDH) has no amino-terminal signal sequence, but instead it has a characteristic hydrophobic domain at the carboxyl terminus (Miyauchi, K., R. Masaki, S. Taketani, A. Yamamoto, A. Akayama, and Y. Tashiro. 1991. J. Biol. Chem. 266:19536-19542). This membrane-bound enzyme is a useful model protein for studying posttranslational localization to its final destination. When expressed from cDNA in COS-1 cells, wild-type msALDH is localized exclusively in the well-developed ER. The removal of the hydrophobic domain results in the cytosolic localization of truncated proteins, thus suggesting that the portion is responsible for membrane anchoring. The last 35 amino acids of msALDH, including the hydrophobic domain, are sufficient for targeting of E. coli beta-galactosidase to the ER membrane. Further studies using chloramphenicol acetyltransferase fusion proteins suggest that two hydrophilic sequences on either side of the hydrophobic domain play an important role in ER targeting.
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PMID:Microsomal aldehyde dehydrogenase is localized to the endoplasmic reticulum via its carboxyl-terminal 35 amino acids. 808 74

Protein disulfide isomerase (PDI) was considered to be involved in the hepatic uptake of certain organic anions because the protein is photoaffinity labeled by photolabile derivatives of the bile acid taurocholate. Several lines of evidences including photoaffinity labeling experiments indicated a close relationship between the uptake of bile acids and the organic anion bumetanide. The possible involvement of PDI in hepatic transport processes of these organic anions was tested with polyclonal antibodies raised against a PDI-beta-galactosidase fusion protein. Western blot analysis and immunofluorescence of intact hepatocytes showed that protein disulfide isomerase is located in sinusoidal rat liver plasma membranes. This protein is immunologically identical with microsomal PDI prepared from bovine liver. The plasma membrane form of PDI is, however, not labeled by photoactivated bumetanide as revealed by two-dimensional gel electrophoresis. These results indicate that, although a membrane-bound form of the PDI is present in the sinusoidal plasma membrane of rat hepatocytes, this protein is not involved in the hepatocellular uptake of the organic anion bumetanide.
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PMID:A membrane-bound form of protein disulfide isomerase (PDI) and the hepatic uptake of organic anions. 827 87

N-Acetyl-D-glucosaminylpyrophosphorylundecaprenol (GlcNAc-P-P-Und), an intermediate in the biosynthesis of the enterobacterial common antigen in E.coli and some O-antigen chains in gram-negative bacteria, is formed by the transfer of GlcNAc 1-P from UDP-GlcNAc to Und-P, analogous to the reaction forming GlcNAc-P-P-dolichol (GlcNAc-P-P-Dol) in mammalian cells. Since the microsomal enzyme from animal cells exhibits a strong preference for Dol-P, which contains a saturated alpha-isoprene unit, the polyisoprenyl phosphate specificity of the homologous bacterial enzyme was characterized. The enzyme remained bound to the membrane fraction when spheroplasts, formed by lysozyme-EDTA treatment, were lysed in hypotonic buffer. GlcNAc-P-P-Und synthase (GPT) activity was elevated in a strain of E.coli bearing the rfe gene, which encodes GPT on a multicopy plasmid, and virtually absent from rfe null mutants. GPT actively utilized fully unsaturated polyprenyl phosphate (Poly-P) substrates with maximal activity seen with (C55) Und-P, but was unable to utilize (C55)Dol-P. This substrate specificity contrasts with the microsomal GPT from pig brain, which actively utilized (C55)Dol-P, but not Und-P, as substrate. GPT activity bound to particulate fractions from three strains of bacilli also exhibited a strict preference for fully unsaturated Poly-P substrates. Unexpectedly, E.coli GPT activity cofractionated with the cytosolic marker enzyme, beta-galactosidase, and not the membrane-bound enzyme, D-lactate dehydrogenase, in cells disrupted in a French pressure cell. The properties and polyisoprenyl phosphate specificity of the soluble form of GPT were identical to the activity associated with the membrane preparations obtained from spheroplasts. The evolutionary and functional significance of the use of polyisoprenyl glycosyl carrier lipids with saturated alpha-isoprene units in eukaryotes remains uncertain.
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PMID:Polyisoprenyl phosphate specificity of UDP-GlcNAc:undecaprenyl phosphate N-acetylglucosaminyl 1-P transferase from E.coli. 913 38


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