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:3.1.3.1 (alkaline phosphatase)
47,916 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

1. The conditions that promoted the solubilization of particulate lactose synthetase were effective for solubilizing the thiamine pyrophosphatase of the Golgi apparatus but differed from those effective for beta-glucuronidase or acid phosphatase of lysosomes. 2. Lactose synthetase-containing particles did not bind Mg(2+) or Cs(+) ions, suggesting that they are not related to endoplasmic reticulum membranes. 3. Intact lactose synthetase and thiamine pyrophosphatase particles banded isopycnically at a density of 1.143 in a sucrose gradient. The dissociated ;A' sub-unit of lactose synthetase, UDP-galactose hydrolase, p-nitrophenyl phosphate acid phosphatase, alkaline phosphatase and phosphodiesterase I were associated with particles of a broad density range from 1.12 to 1.20. Lysosomal enzymes beta-glucuronidase, arylsulphatase and beta-glycerophosphate acid phosphatase were associated with particles of density 1.20, 1.175 and 1.15 respectively. 4. Rate-zonal sedimentation studies indicated that lactose synthetase particles have S(20,w) values exceeding 24000s, corresponding to spherical particles of diameter exceeding 5.4x10(-5)cm. 5. Electron micrographs of lactose synthetase particles purified over 20-fold revealed small spherical bodies (0.1-0.5mu) resembling lysosomes, the smaller of which were attached to membranes, and larger heterogeneous spherical or oval bodies (0.7-1.8mu) resembling lipofuscin secretory granules. 6. The relationship between lactose synthetase particles and the Golgi origin of secretion granules is discussed.
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PMID:The lactose synthetase particles of lactating bovine mammary gland. Characteristics of the particles. 430 May 7

An isotope dilution method, using (32)P-labeled pyrophosphate, has been developed for the measurement of inorganic pyrophosphate (PP(1)) in human plasma. The specificity of the method was better than 90% as assessed by elution patterns during ion-exchange chromatography, by paper chromatography, and by incubation with inorganic pyrophosphatase. The 99% confidence limits for a single estimation of plasma PP(1) was +/-13%. There were no differences in plasma PP(1) between men and women, but the values in young people (0-15 yr) were slightly higher than in older people. The mean concentration (+/-SE) of PP(1) in the plasma of 73 men and women was 3.50 +/-0.11 mumoles/liter (0.217 +/-0.007 mug P/ml) and the normal range (99% limits) was 1.19-5.65 mumoles/liter (0.074-0.350 mug P/ml). It has been suggested that PP(1) may be important in calcium metabolism because PP(1) can prevent the precipitation of calcium phosphates in vitro and in vivo, and can slow the rates at which hydroxyapatite crystals grow and dissolve. Plasma PP(1) was therefore measured in several disorders of bone. Normal values were found in osteogenesis imperfecta, osteopetrosis, "acute" osteoporosis, and primary hyperparathyroidism. Plasma PP(1) was invariably raised in hypophosphatasia. The excess of PP(1) in plasma might be the cause of the defective mineralization in hypophosphatasia and the function of alkaline phosphatase in bone may be to act as a pyrophosphatase at sites of calcium deposition.
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PMID:Inorganic pyrophosphate in plasma in normal persons and in patients with hypophosphatasia, osteogenesis imperfecta, and other disorders of bone. 432 72

Alkaline phosphatase prepared from mammalian cell cultures was found to have alkaline inorganic pyrophosphatase activity. Both of these activities appear to be associated with a single protein, as demonstrated by: (1) concomitant purification of alkaline phosphatase and alkaline inorganic pyrophosphatase; (2) proportional precipitation of alkaline phosphatase and inorganic pyrophosphatase activities by titrating constant amounts of an enzyme preparation with increasing concentration of antibody; (3) immune electrophoresis, which showed that precipitin bands that have alkaline phosphatase activity also have pyrophosphatase activity; (4) inhibition of pyrophosphatase activity by cysteine, an inhibitor of alkaline phosphatase activity; (5) similar subcellular localization of the two enzyme activities as demonstrated by histochemical methods; (6) hormonal and substrate induction of alkaline phosphatase activity in mammalian cell cultures, which produced a nearly parallel rise in inorganic pyrophosphatase activity.
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PMID:Alkaline inorganic pyrophosphatase activity of mammalian-cell alkaline phosphatase. 496 63

Matrix vesicles, associated with initial calcification in cartilage, have been isolated from bovine fetal epiphyseal cartilage. Cartilage was digested with collagenase, then partitioned into seven fractions by differential centrifugation. The cellular fractions contained over 80% of the DNA in the digest. The extracellular fraction that contained matrix vesicles, in which apatite crystals were often seen on electron microscopy, also displayed the highest specific activity for alkaline phosphatase, pyrophosphatase, ATPase, and 5'-AMPase (EC 3.1.3.1., 3.6.1.1, 3.6.1.3, and 3.1.3.5, respectively). Most of the acid phosphatase (EC 3.1.3.2) activity, on the other hand, was found in the cellular fractions, indicating that matrix vesicles are quite distinct from lysosomes. This appears to be the first instance of isolation of membrane-bounded extracellular particles from any normal tissue. The matrix vesicles possess enzymes that can increase the local concentration of orthophosphate and thus could lead to the formation of hydroxyapatite. The membrane-bounded matrix vesicles may also provide a mechanism for ATP-dependent transport of calcium or phosphate into the lumen of the vesicles with resultant mineralization.
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PMID:Isolation and characterization of calcifying matrix vesicles from epiphyseal cartilage. 527 75

1. Dialysed extracts of rat costal cartilage were shown to possess an enzyme that hydrolyses inorganic pyrophosphate. 2. Inorganic pyrophosphatase activity assayed in the presence of 2mm substrate was maximal at pH6.8. 3. Mg(2+) was essential for activity, which was greatest with 10mm or higher concentrations of Mg(2+). 4. Extracts prepared from cartilage taken from suckling rats (<20g.) showed little or no hydrolytic activity, but as rat weight increased inorganic pyrophosphatase activity was detected, increased to a maximum in tissue from animals weighing about 40g., and then rapidly declined. 5. The increase in inorganic pyrophosphatase activity was associated with an increase in the uptake of (45)Ca by the cartilage in vivo. 6. Accumulation of calcium, inorganic phosphate and magnesium occurred when inorganic pyrophosphatase activity was at its maximum. 7. Alkaline phosphatase activity, measured in the same extracts used to determine pyrophosphatase activity, was highest in the tissues of the animals weighing <20g., and decreased as inorganic pyrophosphatase activity increased to its maximum. 8. There was no direct relationship between alkaline phosphatase activity and the onset of calcification.
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PMID:Association of inorganic pyrophosphatase activity with normal calcification of rat costal cartilage in vivo. 580 16

An electron microscope cytochemical technique was used to determine the subcellular distribution of marker enzymes in Fusidium sp. 100-3 cells. Nucleoside diphosphatase was found in the nuclear envelope and intracytoplasmic membrane segment. Thiamine pyrophosphatase was found to be associated with the mesosomes. Cytochrome c (oxidase) activity was found only in the mitochondrial cristae. Strong alkaline phosphatase activity was present in the vacuole; in addition, the enzyme activity was discretely dispersed throughout the cytoplasm without any association with any membrane material. The overall characteristics of the cell ultrastructure and subcellular enzyme distribution of Fusidium sp. 100-3 cells compare fairly well with those of a fungal cell. But there are considerable differences from the characteristics of higher eucaryotic cells. Detailed data on the marker enzymes distribution in a variety of fungal cells are not available. Therefore, it is not possible to conclude whether the marker enzyme distribution of Fusidium sp. 100-3 cells is unique or is typical of any fungal organism. Detailed studies of cell ultrastructure of and marker enzyme distribution in minute fungal cells and their comparison to the ultrastructure of and marker enzyme distribution in other fungal organisms may be helpful in understanding the phylogenetic and ontogenic development of subcellular organelles.
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PMID:Subcellular distribution of marker enzymes in cells of a minute fungus, Fusidium sp. 100-3. 610 54

Ultrastructural localizations of phosphatases were observed in the rat parathyroid gland. Activities of alkaline phosphatase and adenosine triphosphatase were found on the caveolae or pinocytotic vesicles of the capillary endothelia. In the parenchymal cells, they were demonstrated to be stronger both at the plasma membranes facing the pericapillary space and at their transitional portions to the lateral plasma membranes than at the remaining lateral plasma membranes including microvilli. Activities of thiamine pyrophosphatase and inosine diphosphatase were detected on one or two layers of lamellae at the inner face of the Golgi apparatus, and the localization of the latter enzyme was more restricted than that of the former. Additionally, they were sometimes observed also on the blood capillary wall. Contrasted to these enzymes, acid phosphatase activity was demonstrated on the entire Golgi lamellae besides lysosomes, but not on multivesicular bodies, vacuolar bodies and storage granules.
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PMID:Ultrastructural localization of phosphatases in the rat parathyroid gland. 610 56

One abnormality in calcium pyrophosphate deposition disease (CPDD) which fosters consistently high synovial fluid pyrophosphate ion (PPi) and large accumulations of calcium pyrophosphate dihydrate crystals (Ca pyrophosphate) might be an aberration in chondrocytes involving elaboration of PPi and failure of its hydrolysis within cartilage matrix. Exploration of this hypothesis required further information on the phosphohydrolases in relevant human articular cartilages. Triton X-100 extracts of whole homogenized cartilage from 18 patients with primary osteoarthritis (OA), 10 patients with CPDD and secondary OA, as well as 6 "normal" subjects were partially purified by DE-52 chromatography and eluates studied for phosphohydrolase activity in a variety of substrates, inhibitors, and environmental conditions. Almost all the protein as well as crude alkaline phosphatase and pyrophosphatase activities were clustered in peaks designated I and II. Findings in CPDD cartilage not observed in OA controls were: 1) consistent alkaline phosphatase activity in the void volume of DE-52 columns, 2) high levels of 5'nucleotidase activity, 3) abundant generation of PPi by CPDD cartilage during in vitro incubation of cartilage extract fractions with ATP. This enzymatic behavior is likely to bear a regulatory relationship to PPi production by chondrocytes in CPDD.
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PMID:Comparison of phosphohydrolase activities from articular cartilage in calcium pyrophosphate deposition disease and primary osteoarthritis. 611 22

Kupffer cells are the sinusoidal macrophages of the liver. Using ultrastructural phosphatase cytochemical methods, we examined the relationship between the Golgi apparatus, GERL, and lysosomes of Kupffer cells in fetal rat livers identified, in part, by their ability to phagocytize intravenously injected latex spheres. Thiamine pyrophosphatase (TPPase) activity was localized to the inner Golgi saccules and some vesicles in the Golgi region but not to GERL. A TPPase-like activity, demonstrable in lysosomes, was abolished by sodium fluoride but not suppressed by the alkaline phosphatase inhibitors L-cysteine and L-p-bromotetramisole. Acid phosphatase (AcPase) was localized by GERL, some coated vesicles, and in lysosomes, but not to the Golgi stacks. Continuities between GERL and lysosomes were observed. Phagosomes containing internalized latex spheres received TPPase and AcPase sequentially. TPPase was localized in phagosomes immediately after latex administration. AcPase activity was not found here until at least 10 minutes following the injection of the particulates. Our findings indicate that Kupffer cell lysosomes are derived from GERL, but also suggest that phagosomes may receive material packaged by the Golgi apparatus as well as GERL.
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PMID:The relationships between the Golgi apparatus, GERL, and lysosomes of fetal rat liver Kupffer cells examined by ultrastructural phosphatase cytochemistry. 611 32

A new rapid assay for inorganic pyrophosphatase has been developed and the procedure optimised for measurement of the enzyme in human neutrophils. Kinetic studies showed that the activity was optimal at pH 8.0 and was activated by Mg2+. No neutral or acid pyrophosphatase was detected. Neutrophils were homogenised in isotonic sucrose and, after low speed centrifugation the intracellular localization of pyrophosphatase was determined by analytical subcellular fractionation with sucrose density gradient centrifugation. Pyrophosphatase was shown to have a dual localization to mitochondria and cytosol. No activity could be attributed to either the endoplasmic reticulum or alkaline phosphatase-containing granules (phosphasomes). Inhibitor studies clearly show that the cytosolic and mitochondrial pyrophosphatases are due to distinct enzymes. Neutrophils were isolated from control subjects, patients with chronic granulocytic leukaemia and subjects in the third trimester of pregnancy. The specific activity (mU/mg protein) of pyrophosphatase, in contrast to that of alkaline phosphatase was similar in the three groups. Levamisole, a potent inhibitor of alkaline phosphatase had no effect on pyrophosphatase activity, confirming that this activity is not attributable to neutrophil alkaline phosphatase.
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PMID:Subcellular localization and properties of alkaline inorganic pyrophosphatase in human polymorphonuclear leucocytes. 612 Jul 71


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