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)

Nicotinamide adenine dinucleotide phosphate phosphomonoesterase was isolated and partially purified from wheat (Triticum aestivum L. var. Selkirk) leaves. The enzyme had KNADP value of 1.4 X 10(-4) M and a pH optimum of 5.9. In vitro activity of this enzyme was unaffected by precursors of NAD (nicotinamide and nicotinic acid) or cytokinins (kinetin and benzimidazole). However, when detached wheat leaves were treated with solutions of these compounds, the precursors lowered the specific activity while the cytokinins enhanced the activity. It is suggested that spatial separation and compartmentation of the enzyme and its substrate NADP account for the similar effect of benzimidazole on both.
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PMID:Effect of benzimidazole on nicotinamide adenine dinucleotide phosphate phosphomonoesterase activity in wheat leaves. 0 13

A method is described for the localization and characterization of phospholipases A1 and A2 (EC3.1.1.4) in Krebs II ascites cells, particularly in the plasma membranes. Cells were lysed with a Dounce homogenizer in an isotonic sucrose medium. Plasma membranes sediment with mitochondria and lysosomes during subcellular fractionation and are finally isolated on a continuous sucrose gradient. The membranes are localized at two levels in the gradient, at densities of 1.06 and 1.15, in which 5'-nucleotidase (EC 3.1.3.5) activity exhibits a 9- and 21-fold purification, respectively. Total contamination by endoplasmic reticulum, lysosomes, and mitochondria is 17 percent for the low-density membrane fraction and 25 percent for the high-density fraction. The phospholipases A present in Krebs II cells are active at pH 4.0 and pH 7.5. At the 2 pH values, they have A1 and A2 specificities. The intracellular distribution of acidic forms is comparable to that of acid phosphatase (EC 3.1.3.1), while neutral forms are localized like lactate dehydrogenase (EC 1.1.1.27). A small proportion of neutral phospholipase A2 has the same repartition on the sucrose gradient as nicotinamide adenine dinucleotide diaphorase (EF 1.6.4.3), an endoplasmic reticulum marker, and as 5'-nucleotidase, a plasma membrane marker.
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PMID:Phospholipases A1 and A2 in subcellular fractions and plasma membranes of Krebs II ascites cells. 2 44

Two enzymes have been partially purified from extracts of Escherchia coli B which together catalyze the conversion of the product of the action of GTP cyclohydrolase II, 2,5-diamino-6-oxy-4-(5'-phosphoribosylamine)pyrimidine, to 5-amino-2,6-dioxy-4-(5'-phosphoribitylamine)pyrimidine. These two compounds are currently thought to be intermediates in the biosynthesis of riboflavin. The enzymatic conversion occurs in two steps. The product of the action of GTP cyclohydrolase II first undergoes hydrolytic deamination at carbon 2 of the ring, followed by reduction of the ribosylamino group to a ribitylamino group. The enzyme which catalyzes the first step, herein called the "deaminase," has been purified 200-fold. The activity was assayed by detecting the conversion of the product of the reaction catalyzed by GTP cyclohydrolase II to a compound which reacts with butanedione to form 6,7-dimethyllumazine. The enzyme has a molecular weight of approximately 80,000 and a pH optimum of 9.1. The dephosphorylated form of the substrate is not deaminated in the presence of the enzyme. The assay for the enzyme which catalyzes the second step, referred to here as the "reductase," involves the detection of the conversion of the product of the deaminase-catalyzed reaction to a compound which, after treatment with alkaline phosphatase, reacts with butanedione to form 6,7-dimethyl-8-ribityllumazine. The reductase has a molecular weight of approximately 40,000 and a pH optimum of 7.5. Like the deaminase, the reductase does not act on the dephosphorylated form of its substrate. Reduced nicotinamide adenine dinucleotide phosphate is required as a cofactor; reduced nicotinamide adenine dinucleotide can be used about 30% as well as the phosphate form. The activity of neither enzyme is inhibited by riboflavin, FMN, or flavine adenine dinucleotide.
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PMID:Presence of Escherichia coli of a deaminase and a reductase involved in biosynthesis of riboflavin. 3 Jul 56

It is suggested that ABRM, smooth muscle of Mytilus edulis L. and Mytilus galloprovincialis Lmk. (Mollusca Pelecypoda), is composed of one histochemical fibre type. The fibres are characterized by a low myofibrillar ATPase activity. Succinic and nicotinamide adenine dinucleotide oxidoreductase activities are distributed in a reverse pattern than that of the ATPase activity. Glycogen phosphorylase is richly represented in ABRM fibres and this detection is in opposition with the negative detection of alkaline phosphatase activity. These preliminary histochemical observations are similar to those found in some vertebrate smooth muscles. Mitochondrial glycerol-3-phosphate, 6-phosphogluconate, lactate and octopine dehydrogenases are not detected in muscle fibres whereas glio-interstitial tissues show weak but distinct reactivity. These last results especially characterize Mytilus catch fibres and are briefly discussed in relationship with previous physiological, biochemical and morphological observations.
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PMID:Histochemical characteristics of a tonic smooth muscle. 15 82

1. The interaction of NAD+, NADH and various nucleotide analogues with pig kidney alkaline phosphatase (orthophosphoric-monoester phosphohydrolase (alkaline optimum) EC 3.1.3.1) has been investigated by kinetic means. Some inhibitors act uncompetitively whereas others markedly increase the slopes of double reciprocal plots suggesting they have some affinity for the free enzyme. 2. The compounds seem to bind to alkaline phosphatase through interactions of their bases with a relatively non-specific region of the enzyme, although it is likely that for those nucleotides having some affinity for the free enzyme there is some attraction between the pyrophosphate backbone and the active site. 3. From studies of the effect of NAD+ and NADH on ATPase activity it was concluded that the substrate inhibition that is characteristic of the ATPase activity of alkaline phosphatase originates from binding of ATP to the site assumed to exist for NAD+ and NADH. The potentiation of NAD+-inhibition of ATPase activity by Mg-2+ is probably a result of the depletion of [ATP-4-] the true substrate. The depletion allows NAD+ to complete more effectively for the active site. 4. Binding of NADH is favoured by protonation of an enzymic group with a pK of approx. 9.0 belonging possibly to a tyrosine residue or a zinc hydrate. 5. A large entropy decrease was found to accompany the binding of NAD+ and NADH to alkaline phosphatase. This may be further evidence of an "induced-fit" mechanism previously suspected because of the synergistic inhibitory effects of adenosine and nicotinamide.
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PMID:Nicotinamide-adenine dinucleotide inhibition of pig kidney alkaline phosphatase. 23 67

A cyclic nucleotide-binding phosphohydrolase that possesses both a phosphomonoesterase and a phosphodiesterase catalytic function has been partially purified from Aspergillus nidulans. The enzyme hydrolyzes both p-nitrophenylphosphate and bis-(p-nitrophenyl)-phosphate. o'-Nucleoside monophosphates are the best physiological phosphomonesterase substrates but 5'- and 2'-nucleoside monophosphates are also hydrolyzed. The enzyme catalyzes the hydrolysis of adenosine 5'-triphosphate, adenosine 5'-diphosphate, and 2',3'- and 3'5'-cyclic nucleotides, but not of ribonucleic acid, deoxyribonucleic acid, or nicotinamide adenine dinucleotide. The enzyme has acid pH optima and is not activated by divalent cations. Nucleosides and nucleotides inhibit the enzyme. Cyclic nucleotides are competitive inhibitors of the phosphodiesterase-phosphomonoesterase. The enzyme can occur extracellularly. The phosphodiesterase-phosphomonoesterase is present at high levels in nitrogen-starved mycelium, and it is strongly repressed during growth in media containing ammonium or glutamine and weakly repressed during growth in glutamate-containing medium. Experiments with various area mutants show that this regulatory gene is involved in the control of the enzyme. No evidence for regulation of the enzyme by carbon or phosphorus starvation has been found.
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PMID:Enzymology and genetic regulation of a cyclic nucleotide-binding phosphodiesterase-phosphomonoesterase from Aspergillus nidulans. 24 43

7 infants diseased with Acrodermatitis enteropathica and 10 normal controls were included in this study. The values of anthranilic acid glucuronide, 6- aminohippuric, anthranilic acid, N-acetyl Kneurine, Kneurine and 30 H Kneurenine, were estimated in mg/24 hours urine, both basal and after tryptophane load. In addition, histopathological and histochemical studies for lactase, succinic dehydrogenase, alkaline phosphatase, acid phosphatase, and alpha-non-specific esterases activities were done for the intestinal mucosal biopsies. All the previous investigations were then repeated after two months treatment with 500 mg/day diiodohydroxyquinoline. The tryptophan metabolites were significantly low in the diseased infants, both basal and after tryptophan load. Moreover, the intestinal enzymes activities were altered. After 2 months treatment with diiodohydroxyquinoline the diseased infants became clinically improved, tryphtophan metabolites became normal, but the activities of the intestinal enzymes were not altered. The biochemical and histochemical findings were discussed, giving the possibility of competitive inhibition of the diiodohydroxyquinolines and the by-product 8 OH Quinololic acid resulting in more degradation of Kneurine and 3 OH Kneurenine to nicotinamide adenine dinucleotide.
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PMID:Clinical, biochemical and histochemical studies on infants with Acrodermatitis enteropathica chronica. 82 55

Phenotypes of the cells developing into small colonies after days of primary culture of adult rat hepatocytes in serum-free modified Dulbecco Modified Eagles' medium containing 10 mM nicotinamide and 10 ng/ml epidermal growth factor were analyzed immunocytochemically, cytochemically and ultrastructurally. Albumin, cytokeratin 8 and 18 were seen by immunocytochemical techniques in the cells of the small colonies at Day 6. Transferrin, alpha 1-antitrypsin, ceruloplasmin, and haptoglobin, proteins secreted by mature hepatocytes, were faintly stained in these cells as was alpha-fetoprotein. These proteins were secreted into the culture medium as evidenced by immunoblot analysis. gamma-Glutamyltransferase, alkaline phosphatase and glucose 6-phosphatase were not present in the cells of the small colonies as well as the surrounding hepatocytes at Day 6 of culture. In addition, ultrastructural examinations of the cells in the small colonies indicated that these cells not only had many characteristic mitochondria and desmosomes, but also a few small peroxisomes. Such cells, even after 20 days in culture were proliferating, as evidenced by the intranuclear presence of the proliferating cell nuclear antigen. The potential relation of these cells to hepatocytes which may serve as the principal reserve for replicating hepatocytes is discussed.
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PMID:Characteristics of small cell colonies developing in primary cultures of adult rat hepatocytes. 127 92

A nonisotopic assay of vitamin B-12 in human serum or plasma is described, performed with the Abbott IMx analyzer. The sample is first treated at pH > 12.5 to release bound vitamin B-12 and to convert all forms to cyanocobalamin. Next, the analyte is bound, at lower pH, by vitamin B-12-specific binding protein, immobilized to a solid phase of polymeric microspheres. Detection involves monitoring the activity of the tracer enzyme (alkaline phosphatase) coupled to a derivative of cyanocobalamin. Total assay precision is 7.9% for vitamin B-12 at 200 ng/L, 6.6% at 400 ng/L, and 6.7% at 800 ng/L. Assay sensitivity, calculated as 2 SD from the zero calibrator, is 37 (+/- 9) ng/L. The dynamic range extends to 2000 ng/L. Analytical recovery of 300 and 600 ng/L additions of vitamin B-12 to sera with basal concentrations of 30-400 ng/L was 102.5%. Results of the assay correlated well with those of commercially available radioisotope assays. No interference was observed in specimens from patients with pernicious anemia, chronic or acute myelogenous leukemia, or renal failure. Cross-reactivity with cobinamide (1 g/L) was < 0.00003%. Vitamin B-12 measurements for blood specimens drawn into serum, EDTA, or heparinized plasma-collection tubes agreed within 3%.
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PMID:Automated assay of vitamin B-12 by the Abbott IMx analyzer. 139 92

Monoclonal antibodies (McAbs) specific to methamphetamine (MA) were produced using p-amino MA coupled to bovine serum albumin (BSA) with glutaraldehyde (GA) as an immunogen and with conventional hybridoma techniques. Hybridoma clones secreting the McAbs were selected by an enzyme-linked immunosorbent assay (ELISA) system using both the above conjugate and BSA modified with GA as screening antigens. In the ELISA system were used avidin and biotinyl-alkaline phosphatase which converts nicotinamide adenine dinucleotide phosphate (NADP) into NAD. The final enzyme activity was determined using diformazan of nitroblue tetrazolium formed together with the NAD produced, alcohol dehydrogenase and phenazine methosulfate. The McAbs from 9 clones were characterized by a crossreactivity test using the ELISA. The McAbs recognized MA (100%), methoxyphenamine (8.0%), ephedrine (2.3%), but did not react with metylephedrine, amphetamine, OH-amphetamine, dimethylamphetamine, beta-phenylethylamine, norephedrine, phentermine and ranitidine. An inhibition curve for MA was obtained in the range of 0.75 to 50 ng.
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PMID:Development of monoclonal antibodies reactive with methamphetamine raised against a new antigen. 204 81


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