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)

Several recent studies have suggested that the alkaline phosphatase situated in the brush border membrane of the proximal convoluted tubule is positively related to inorganic phosphate reabsorption through this segment of the nephron. We examined this hypothesis by studying the influence of an inhibitor of alkaline phosphatase, L-bromotetramisole, upon phosphate transport through the isolated rabbit tubule, phosphate transport through brush border membrane vesicles of rats, and phosphate efflux from these vesicles. Results were compared with those obtained with D-bromotetramisole which is inactive on alkaline phosphatase. The microperfusion studies on isolated tubules did not show any significant influence of L-bromotetramisole on phosphate transport which slightly increased by 0.22 +/- 0.78 pmol . mm-1 . min-1 (NS). The experiments performed on brush border membrane vesicles indicated that at pH 7.5, both L- and D-bromotetramisole at a concentration of 0.1 mM slightly but significantly increased phosphate input from 1800 +/- 149 to 1999 +/- 157 and 1982 +/- 168 pmol/mg protein per 30-S incubation (P less than 0.01 and P less than 0.005, respectively). At pH 8.5, the same tendency was observed but was significant with the D isomer only. Finally, the effect of an increasing phosphate transport was accentuated when both isomers were tested at 1.0-mM concentration. Phosphate efflux from brush border membrane vesicles was not influenced by L- or D-bromotetramisole at 0.1 mM. At 1.0 mM, however, both isomers accelerated this release. These results do not support the hypothesis of a direct action of alkaline phosphate upon phosphate transport through the entire proximal convoluted tubule, nor upon input or output of this electrolyte through the brush border membrane vesicles. The two forms of bromotetramisole have variable effects upon phosphate transport which are unrelated to the alkaline phosphatase activity.
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PMID:Effects of L-bromotetramisole on phosphate transport by the proximal renal tubule: failure to demonstrate a direct involvement of alkaline phosphate. 707 19

The bacteriophage T7 induced DNA polymerase, consisting of the phage specified gene 5 protein associated with Escherichia coli thioredoxin, catalyzes the copolymerization of SP-dATP alpha S with dTTP, producing the alternating of polymer poly[dTs-A)] by a mechanism involving inversion of configuration at P alpha. Degradation of poly[d(5s-A)] by the nucleolytic action of E. coli DNA polymerase produced the dinucleotide pdTps-dA, whose configuration at the phosphorothioate diester was assigned as R by comparison of the phosphorus-31 nuclear magnetic resonance chemical shift (55.0 ppm downfield from H3PO4) with that of an authentic sample. Further degradation by alkaline phosphatase to Rp-dTps-dA (55.6 ppm downfield from H3PO4) confirmed the configuration. The stereochemistry provides no evidence of a double displacement mechanism.
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PMID:Stereochemical course of nucleotidyl transfer catalyzed by bacteriophage T7 induced DNA polymerase. 709 4

A cloning method utilizing the enzyme histochemical procedure was applied to isolate variant HeLa subclones which produce different alkaline phosphatase isozymes. Phosphate was used to distinguish between Kasahara isozyme and Regan isozyme. The use of filter paper made it possible to determine the localization of the Kasahara isozyme-positive colonies. By this method, two variant clones, HeLa S3-10 KP and HeLa S3-10 KN, were isolated. Kasahara isozyme was induced in the former by increased cell density, but not in the latter.
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PMID:Application of the enzyme histochemical method for the isolation of HeLa variant inducibly producing the Kasahara isozyme of alkaline phosphatase. 722 19

Polyphosphate metabolism in Escherichia coli was studied in order to determine the role of polyphosphates in energy and phosphate metabolism. Phosphate-shift experiments were performed on wild-type E. coli W3110 and on an E. coli strain mutant in the genes encoding the polyphosphate-metabolizing enzymes polyphosphate kinase (PPK) and polyphosphatase (PPX). The levels of polyphosphates were measured by [31P]NMR, and the activities of PPK and PPX were measured using enzymatic assays. During phosphate starvation, the intracellular level of polyphosphate was not detectable in E. coli W3110; the activities of PPX and alkaline phosphatase were high relative to those during exponential growth. During the shift from phosphate starvation to phosphate surplus conditions, PPX activity decreased and PPK activity and intracellular polyphosphate stores increased dramatically. These results imply an important role for polyphosphates in cellular energy and phosphate storage and in adaptation to adverse growth conditions.
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PMID:Polyphosphate metabolism in Escherichia coli. 783 34

The X-linked Hyp mouse, a murine homologue of X-linked hypophosphatemia in humans, is characterized by rachitic bone disease, hypophosphatemia, impaired renal brush-border membrane Na(+)-phosphate cotransport and abnormal regulation of renal vitamin D metabolism. We demonstrated that short-term phosphate supplementation decreases renal 1,25-dihydroxyvitamin D3 (1,25-(OH)2D) catabolism and increases serum 1,25-(OH)2D levels in Hyp mice (Tenenhouse & Jones 1990). In the present study, we compared several other parameters in normal and Hyp mice fed control (1%) and high (1.6%) phosphate diets for 4 days. Phosphate supplementation significantly raised serum phosphate levels and decreased renal brush-border membrane Na(+)-phosphate but not Na(+)-glucose, cotransport in both genotypes (67% of control diet, p < 0.05). However, under both dietary conditions, the phosphate/glucose transport ratio was significantly reduced in Hyp mice (58% of normal littermates, p < 0.05). Renal PTH-stimulated cAMP accumulation, which was significantly blunted in Hyp mice compared to normal mice under control dietary conditions (p < 0.05), was not altered by phosphate supplementation in either genotype. Serum alkaline phosphatase activity was significantly higher than normal in Hyp mice on the control diet and was further increased in mutants but not in normals fed the high phosphate diet (p < 0.05). Measurements of serum bilirubin and electrophoresis of serum alkaline phosphatase suggested that the elevation in serum alkaline phosphatase activity in phosphate-supplemented Hyp mice represents the bone-derived isozyme.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Effect of phosphate supplementation on the expression of the mutant phenotype in murine X-linked hypophosphatemic rickets. 787 97

Procedures that combine immunocytochemistry (ICC) and in situ hybridization (ISH) techniques are now used to investigate phenotype/genotype relationships in the same cells. In this report we describe three rapid procedures for simultaneous detection of a nuclear antigen, progesterone receptors (PR), and the centromeric region of chromosome 11 (to which the human PR gene has been assigned) in T47-D cells. Proteins were stained by precipitates of horseradish peroxidase-diaminobenzidine (PO-DAB, brown color), alkaline phosphatase-Fast Red (APase-Fast Red, red color) or alkaline phosphatase-nitroblue tetrazolium-X-phosphate (APase-NBT-X-Phosphate, blue color) respectively. To obtain a suitable contrast for the two labels, we detected DNA on PO-DAB and APase-NBT-X-phosphate-immunostained cells with interphasic fluorescent in situ hybridization (FISH). By contrast, we combined the APase-Fast Red ICC with an immunocytochemical ISH using alkaline phosphatase-NBT-X-phosphate detection. Only the procedure combining APase-NBT-X-phosphate ICC and FISH ensures optimal visualization of both the PR content and the number of chromosome 11. This method easily provides simultaneous localization of DNA and protein targets in the same cells and should be applicable to many other situations.
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PMID:Methods for simultaneous interphase in situ hybridization and nuclear antigen immunocytochemistry in T47-D cells. 860 77

One thousand male Hubbard chicks were used in a 21-d study (10 birds per battery cage) to determine relative biological availability of phosphorus in seven samples of commercial dicalcium phosphate, expected to contain variable amounts of monocalcium phosphate. Five samples were from established producers in Brazil and two from the U.S. Pure calcium phosphate dibasic dihydrate was used as the reference standard. Phosphates were added to the corn-soybean basal diet (22.5% CP; 0.4% total phosphorus) to provide 0.1, 0.2, and 0.3% supplemental phosphorus. The calcium level was 1.0% for all diets. Left tibias were removed for bone ash (BA) and bone strength (BS) determination. Body weight, feed intake (FI), BA, BS, and plasma phosphorus increased (P < 0.01) and plasma calcium and alkaline phosphatase decreased (P < 0.01) with increasing dietary phosphorus regardless of source. The availability of phosphorus for each test phosphate was determined by slope ratio, with BW, BA, and BS regressed on phosphorus added within each phosphorus source. A relative biological value (RBV) was calculated based on BW, BA, and gain:feed ratio. Availability based on BW ranged from 97.07 to 110.41%. When BA was the criterion, values were 80.32 to 107.84% and for BS were 79.34 to 110.52%. The RBV ranged from 97.55 to 100.60%. Phosphate sources did not vary greatly in phosphorus availability. Overall phosphorus availability averages were higher for BW (103%) and RBV (99%) and lowest for BA (96%) and BS (94%).
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PMID:Biological evaluations of commercial dicalcium phosphates as sources of available phosphorus for broiler chicks. 943 86

The phosphomonoesterases catalyse the hydrolysis of primary esters of phosphoric acid which help the bacteria to survive in phosphate stressed environment. Ninety-five bacterial isolates were obtained from domestic sewage and industrial effluents of gelatine and soap factories at Jabalpur on a medium enriched with phosphate and were screened for phosphatase production. The phosphatase producers were tentatively identified as Escherichia coli, Vibrio vulnificus, Aeromonas hydrophila, Staphylococcus aureus, Pseudomonas maltophilia and Micrococcus varians. The in vitro studies on the production of phosphomonoesterases by bacteria was conducted. The maximum alkaline phosphatase production was recorded on 8th day of incubation by E.coli and P.maltophilia, on 10th day of incubation by V.vulnificus while M.varians and P.maltophilia produced higher acid phosphatase on 4th and 10th day of incubation respectively. The detailed investigations were done to find out the effect of various physical and chemical factors on phosphomonoesterases activity and the optimum conditions required for enzyme activity.
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PMID:Activity of bacterial phosphomonoesterases in batch culture. 953 56

The purpose of the study was to evaluate the effectiveness of the oral pulse therapy with high doses of alphacalcidol (1 alpha(OH)D3) in secondary hyperparathyroidism. 16 hemodialysis patients with 4 to 9-fold iPTH serum elevation were given ones in week oral 1 alpha(OH)D3 in doses from 5.0 to 7.0 micrograms (0.1 microgram/b.m.) according to serum levels of calcium, phosphate, activity of alkaline phosphatase with its bone fraction. Serum iPTH levels were measured every 3rd month of the treatment. The dialysate calcium was reduced to 1.25 mmol/l. CaCO3 was used as a main phosphate binder in doses from 3.0 to 9.0 g/day. After first three months of treatment the serum iPTH levels decreased from 486.0 +/- 200 pg/ml to 218.0 +/- 117 pg/ml (p = 0.0001). Calcium levels increased from 2.39 +/- 0.2 mmol/l to 2.52 +/- 0.29 mmol/l (p > 0.05). Phosphate levels increased from 2.15 +/- 0.67 mmol/l to 2.17 +/- 0.62 mmol/l (p > 0.05). Alkaline phosphatase levels decreased from 35.2 +/- 17.3 IU/l to 31.1 +/- 7.78 IU/l (p > 0.05). Bone isoenzyme of alkaline phosphatase decreased from 19.2 +/- 13.4 IU/l to 15.5 +/- 7.51 IU/l (p > 0.05). Because of early serum hypercalcemia, doses of 1 alpha(OH)D3 had to be reduced in 2 patients. In 8 patients (50%) demonstrating decrease of serum iPTH levels (below 200 pg/ml) after first 3 months of treatment doses of 1 alpha(OH)D3 were reduced in the following months. We conclude that oral 1 alpha (OH)D3 pulse therapy is effective for parathyroid activity suppression in patients with severe hyperparathyroidism. To avoid dangerous hypercalcemia and adynamic bone disease serum iPTH and calcium levels should be strictly monitored.
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PMID:[Evaluation of the treatment efficacy of secondary hyperparathyroidism with oral pulse doses of alphacalcidol]. 955 90

A disposable immunomagnetic electrochemical sensor involving a magnetic particle-based solid phase and a Nafion film-coated screen-printed electrode (Nafion-SPE) stuck at the bottom of a polystyrene cylinder (microwell of 300 microL) was developed and evaluated in a competitive immunoassay of the widely used herbicide 2,4-dichlorophenoxyacetic acid (2,4-D). The competitive binding of 2,4-D and 2,4-D labled with alkaline phosphatase (AP) for a limited amount of polyclonal anti-2,4-D antibody-coated magnetic beads was monitored electrochemically by measuring the AP labled++ activity bound to the beads. The phosphoric acid ester of [[(4-hydroxyphenyl)amino]-carbonyl]cobaltocenium hexafluorophosphate was used as the AP substrate. This anionic substrate (S-) is enzymatically transformed at pH 9.0 into a cationic phenol derivative (P+) which can be easily accumulated in the polyanionic Nafion coating and determined by cyclic voltammetry. During the enzyme reaction, the AP-associated beads were localized on the surface of the Nafion-SPE with the aid of a magnet, thus effectively increasing the concentration of P+ in the Nafion-modified electrode vicinity. The enzyme generation of P+ close to the electrode surface, and thereby to the Nafion film, resulted in a high amplification of the response. A detection limit of 0.01 microgram L-1 2,4-D was thus achieved. The performance of the sensor was successfully evaluated on river water samples spiked with 2,4-D, indicating that this convenient and sensitive technique offers great promise for decentralized environmental applications.
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PMID:An immunomagnetic electrochemical sensor based on a perfluorosulfonate-coated screen-printed electrode for the determination of 2,4-dichlorophenoxyacetic acid. 1040 15


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