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)

4-Nitrophenyl and 2-napthyl monoesters of phenylphosphonic acid have been synthesized, and an enzyme catalyzing their hydrolysis was resolved from alkaline phosphatase of a commerical calf intestinal alkaline phosphatase preparation by extensive ion-exchange chromatography, chromatography on L-phenylalanyl-Sepharose with a decreasing gradient of (NH4) 2SO4, and gel filtration. Detergent-solubilized enzyme from fresh bovine intestine was purified after (NH4)2SO4 fractionation by the same technique. The purified enzyme is homogeneous by polyacrylamide gel electrophoresis and sedimentation equilibrium centrifugation. It has a molecular weight of 108,000, contains approximately 21% carbohydrate, and has an amino acid composition considerably different from that reported from alkaline phosphatase from the same tissue. The homogeneous intestinal enzyme, an efficient catalyst of phosphonate ester hydoolysis but not of phosphate monoester hydrolysis, was identified as a 5'-nucleotide phosphodiesterase by its ability to hydrolyze 4-nitrophenyl esters of 5'-TMP but not of 3'-TMP. Also consistent with this identification was the ability of the enzyme to hydrolyze 5'-ATP to 5'-AMP and PPi, NAD+ to 5'-AMP and NMN, TpT to 5'-TMP and thymidine, pApApApA to 5'-AMP, and only the single-stranded portion of tRNA from the 3'-OH end. Snake venom 5'-nucleotide phosphodiesterase also hydrolyzes phosphonate esters, but 3'-nucleotide phosphodiesterase of spleen and cyclic 3',5'-AMP phosphodiesterase do not. Thus, types of phosphodiesterases can be conveniently distinguished by their ability to hydrolyze phosphonate esters. As substrates for 5'-nucleotide phosphodiesterases, phosphonate esters are preferable to the more conventional esters of nucleotides and bis(4-nitrophenyl) phosphate because of their superior stability and ease of synthesis. Furthermore, the rate of hydrolysis of phosphonate esters under saturating conditions is greater than that of the conventional substrates. At substrate concentrations of 1 mM the rates of hydrolysis of phosphonate esters and of nucleotide esters are comparable and both superior to that of bis(4-nitrophenyl) phosphate.
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PMID:Hydrolysis of phosphonate esters catalyzed by 5'-nucleotide phosphodiesterase. 17 Sep 64

Lactate dehydrogenase and alkaline phosphatase activities in the same medium can be determined simulataneously, at 350 and 550 nm, with a vidicon spectrometer. Substrate concentrations and ph have been made optimum for the combined analysis. These conditions result in activities for lactate dehydrogenase that are equivalent to those found by methods in common use, and activites for alkaline phosphatase that are about 31% below the maximum values that could be obtained with its substrate used at the same ph and temperature in the absence of NAD+ and lactate. However, activites measured by the simultaneous analysis were proportional to those obtained by other methods used in clinical laboratories, and the coefficients of variation were 2.3% for lactate dehydrogenase and 3% for alkaline phosphatase.
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PMID:Vidicon spectrometer applied to simultaneous enzyme determinations. 23 3

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 simple and sensitive method has been described for the determination of UDPglucuronic acid pyrophosphatase activity. Pyrophosphatase-free alkaline phosphatase preparation is added to the reaction mixture in order to hydrolyze the phosphate esters (UMP and alpha-D-glucuronic acid 1-phosphate) produced by pyrophosphatase. The inorganic phosphate liberated is measured by a modification of Fiske and SubbaRow's method. The phosphatase coupled method is time saving, easy to perform and accurate. It can also be used for pyrophosphatase assays with other nucleotide substrates like UDPglucose, UDP-N-acetylglucosamine, NAD+, NADH, NADP+ and NADPH.
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PMID:UDPglucuronic acid pyrophosphatase assay with the aid of alkaline phosphatase. 84 23

N-Arylazido-beta-alanyl-NAD+ [N3'-O-(3-[N-(4-azido-2-nitrophenyl)amino]propionyl)NAD+] has been prepared by alkaline phosphatase treatment of arylazido-beta-alanyl-NADP+ [N3'-O-(3-[N-(4-azido-2-nitrophenyl)amino]propionyl)NADP+]. This NAD+ analogue was found to be a potent competitive inhibitor (Ki = 1.45 microM) with respect to NADH for the purified bovine heart mitochondrial NADH dehydrogenase (EC 1.6.99.3). The enzyme was irreversibly inhibited as well as covalently labeled by this analogue upon photoirradiation. A stoichiometry of 1.15 mol of N-arylazido-beta-alanyl-NAD+ bound/mol of enzyme, at 100% inactivation, was determined from incorporation studies using tritium-labeled analogue. Among the three subunits, 0.85 mol of the analogue was bound to the Mr = 51,000 subunit, and each of the two smaller subunits contained 0.15 mol of the analogue when the dehydrogenase was completely inhibited upon photolysis. Both the irreversible inactivation and the covalent incorporation could be prevented by the presence of NADH during photolysis. These results indicate that N-arylazido-beta-alanyl-NAD+ is an active-site-directed photoaffinity label for the mitochondrial NADH dehydrogenase, and are further evidence that the Mr = 51,000 subunit contains the NADH binding site. Previous studies using A-arylazido-beta-alanyl-NAD+ [A3'-O-(3-[N-(4-azido-2-nitrophenyl)amino]propionyl)NAD+] demonstrated that the NADH binding site is on the Mr = 51,000 subunit [Chen, S., & Guillory, R. J. (1981) J. Biol. Chem. 256, 8318-8323]. Results are also presented to show that N-arylazido-beta-alanyl-NAD+ binds the dehydrogenase in a more effective manner than A-arylazido-beta-alanyl-NAD+.
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PMID:N-arylazido-beta-alanyl-NAD+, a new NAD+ photoaffinity analogue. Synthesis and labeling of mitochondrial NADH dehydrogenase. 234 Feb 77

A recycling assay for alkaline phosphatase, based on its ability to hydrolyse NADP to NAD+, is presented. The product NAD+ is recycled in a coupled assay consisting of NADH regeneration and reduction of a nitroblue tetrazolium salt. This assay is 10-12 times more sensitive than the conventional assay. We demonstrate the role of energy poisons in transport of this protein into the periplasm by combining the improved detection with phase separation of the periplasmic and cytoplasmic alkaline phosphatase pools.
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PMID:A recycling assay for alkaline phosphatase applied to studies on its transport in E. coli K12. 269 14

In previous studies we found that intraperitoneal injection of nicotinamide (NiAm) to rats resulted in increased NAD+ content in proximal tubules, inhibition of brush border membrane (BBM) transport of phosphate (Pi) and decreased activity of alkaline phosphatase (AP). We now studied the effect of NiAm injection on rabbit kidney BBM prepared either directly by Ca2+ precipitation method, or prepared indirectly from sheets of BBM. In BBM vesicles prepared directly from NiAm-injected rabbits, Na+-dependent Pi uptake was inhibited, but no inhibition was found in BBM vesicles prepared by an indirect method. Incubation of both directly prepared BBM vesicles and of BBM sheets with phosphatidylinositol-specific phospholipase C (PI-PLC) released about 85% of AP from BBM. In BBM vesicles prepared indirectly from BBM sheets, incubation with PI-PLC increased by 100% the capacity for Pi transport, but PI-PLC had no effect on Pi transport if rabbits were injected with NiAm. On the other hand, incubation of directly prepared BBM vesicles with PI-PLC did not alter Pi transport capacity both in controls and in NiAm-treated rabbits, although it released AP. Treatment with NiAm decreases significantly AP activity both in BBM vesicles prepared directly or prepared indirectly from BBM sheets. These results suggest that NiAm-induced inhibition of BBM transport system for Pi is reversed by prolonged washing and incubation in the course of indirect preparation of BBM vesicles. Results also suggest that an increase in tissue NAD+ decreases susceptibility of BBM to treatment with PI-PLC in altering Pi transport. Removal of the majority of AP from BBM does not impair Na+-gradient-dependent Pi transport system.
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PMID:Studies on rabbit kidney brush border membranes: relationship between phosphate transport, alkaline phosphatase and NAD. 296 74

The metabolic effects of ethanol are due to a direct action of ethanol or its metabolites, changes in the redox state occurring during its metabolism, and modifications of the effects of ethanol by several nutritional factors. Ethanol causes hyperglycemia or hypoglycemia depending whether or not glycogen stores are adequate, inhibits protein synthesis, and results in a fatty liver and elevations in serum triglyceride levels. Increases in serum lactate, results from the increased reduced nicotinamide-adenine dinucleotide/nicotinamide-adenine dinucleotide + (NADH/NAD+) ratio, and hyperuricemia probably occurs owing to the increased turnover of adenine nucleotides after ethanol ingestion. Ethanol decreases thiamine absorption and decreases the enterohepatic circulation of folate. Acetaldehyde, the major metabolite of ethanol, increases the degradation of pyridoxal 5'-phosphate by displacing it from its binding protein and making it susceptible to hydrolysis by membrane-bound alkaline phosphatase. Chronic ethanol administration also results in decreased vitamin A stores and reduced bone mass and blood levels of 25-hydroxyvitamin D. The mechanism whereby ethanol affects these vitamins and their associated enzymes is unknown.
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PMID:The effect of ethanol and its metabolites on carbohydrate, protein, and lipid metabolism. 329 39

We have demonstrated that the purified guanine nine nucleotide exchange factor (GEF) may be isolated as a complex with NADPH. Complete inhibition of the GEF-catalyzed exchange of eukaryotic initiation factor 2-bound GDP for GTP was observed in the presence of either 0.5-0.75 mM NAD+ or NADP+. Incubation of GEF with ATP results in the phosphorylation of its Mr 82,000 polypeptide. This phosphorylation is strongly inhibited by heparin but is not affected by heme or H8 (N-[2-(methylamino)ethyl]-5-isoquinolinesulfonamide dihydrochloride), an inhibitor of cAMP- and cGMP-dependent protein kinases and protein kinase C. The purification of GEF was modified to eliminate any contaminating kinase activity and the isolated protein appears to be homogeneous as judged by NaDodSO4/polyacrylamide gel electrophoresis and silver staining. The Mr 82,000 subunit of GEF is phosphorylated only upon addition of ATP and casein kinase II. The extent of phosphorylation is approximately equal to 0.55 mol of phosphate per mol of GEF, and this results in a 2.3-fold increase in the guanine nucleotide exchange activity. Following treatment of the phosphorylated GEF with alkaline phosphatase, the activity of the protein is reduced by a factor of 5. Rephosphorylation of GEF increases its specific activity to that of the phosphorylated protein. The results of this study suggest that phosphorylation/dephosphorylation of GEF plays a role in regulating polypeptide chain initiation.
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PMID:Phosphorylation of the guanine nucleotide exchange factor from rabbit reticulocytes regulates its activity in polypeptide chain initiation. 342 26

We describe methods for automated enzymatic measurement of lecithin, sphingomyelin, and phosphatidylglycerol in amniotic fluid. Phospholipase C (EC 3.1.4.3) and sphingomyelin phosphodiesterase (EC 3.1.4.12) are reacted with lecithin and sphingomyelin, respectively, to liberate phosphocholine. Phosphocholine is then reacted with alkaline phosphatase, choline oxidase, peroxidase, and 4-aminoantipyrine to form a colored complex, for which the absorbance at 500 nm is measured with a centrifugal analyzer. Phosphatidylglycerol is hydrolyzed by phospholipase D (EC 3.1.4.4) to form glycerol, which is subsequently reacted with ATP and NAD+ in the presence of glycerol kinase and glycerol-3-phosphate dehydrogenase to yield NADH. The absorbance of the NADH formed is measured at 340 nm. These methods provide a simple, rapid, and accurate alternative to thin-layer chromatography for determination of phospholipids in amniotic fluid for assessment of fetal lung maturity.
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PMID:Automated enzymatic measurement of lecithin, sphingomyelin, and phosphatidylglycerol in amniotic fluid. 380 1


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