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)

Partially purified enzyme fraction from rat kidney possessing high uridine kinase and phosphomonoesterase activity was insolubilized by means of zinc precipitation without substantial loss of the activity. While uridine kinase in a soluble and Zn-precipitated form was inhibited by low concentrations (0.5-1.0 mM) of Zn2+-ions, phosphomonoesterase was fully active. In contrast to the soluble fraction, the two enzymes in zinc-precipitated and lyophilized preparations were stable on heating at 100 degrees C. Metal complexed proteins catalyze the dephosphorylation of 5'-UMP, 6-AzaUMP as well as of 2'(3')-UMP or 2,4-dinitrophenyl phosphate indicating thus the presence of several phosphomonoesterases in the complex.
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PMID:Coprecipitation of active uridine kinase and phosphomonoesterase from rat kidney by Zn2+-ions. III. Enzymes relevant to cancer chemotherapy. 1 85

Alkaline phosphomonoesterase (EC 3.1.3.1) activity from Blastocladiella emersonii, while displaying typically broad substrate specificity for phosphorylated organic compounds, exhibited nearly complete substrate preference for N-acetylglucosamine-6-phosphate over N-acetylglucosamine-1-phosphate. Enzyme in zoospore extracts was purified 43-fold by differential centrifugation followed by gel filtration (Sephadex G-200) and then by ion-exchange chromatography (diethylaminoethyl-cellulose). The partially purified enzyme displayed an apparent molecular weight (Sephadex G-200) of approximately 170,000. The activity of partially purified enzyme exhibited a pH optimum of pH 8.5, did not require a metal divalent cation, but was inhibitable by ethylenediaminetetraacetic acid. During the life cycle of the organism, the specific activity of the phosphatase decreased slightly during germination and early exponential growth but then increased about 4.5-fold during sporulation. B. emersonii alkaline phosphatase does not appear to be a repressible enzyme.
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PMID:Alkaline phosphatase of Blastocladiella emersonii: partial purification and characterization. 1 78

The aims of this study were to determine the effect of levels of various substances and reaction by-products, which are formed during hydrolysis of nucleic acids, on the derivatization and chromatography of nucleosides; and to investigate the silylation of mono- and dinucleotides. The effect of NaCl, KCl, MgCl2, NH4Cl, and (NH4)2SO4 on silylation and chromatography of nucleosides was studies at various molar excesses of salt. The response values for all nucleosides were studied at various molar excesses of salt. The response values for all nucleosides were significantly affected at molar excess salt present values (MSP) between 1 and 10 for KCl, NaCl, NH4Cl, (NH4)2SO4 and between 0.1 and 1 for MgCl2. It was noted that thymidine was more sensitive than other nucleosides if silylated in presence of these salts. Two chromatographic peaks at retention temperatures (RT) 240 and 251 were obtained for cytidine at MSP values of 10(-3) for NaCl, KCl, and MgCl2, and 10(-4) for NH4Cl and (NH4)2SO4. In a mixture of nucleosides the RT = 251 peak was used for quantitative analysis of cytidine as the RT = 240 peak elutes with guanosine. Thus, these salts have a significant effect on the gas-liquid chromatography of trimethylsilyl (TMS) cytidine in a mixture of nucleosides, especially the RT = 241 peak. The effect of salts on derivatization can be explained in part as follows: (a) reduced derivatization of nucleosides due to a decreased solubility in the solvent system; (b) formation of TMS anion derivatives, e.g. TMS-SO4, TMS-PO4, with a reduced molar excess of BSTFA; (c) metal chelation by Mg ions or other divalent cations with nucleosides or BSTFA; and/or (d) an increased breakdown of TMS derivatives in presence of salt in the sample or on the top 3 in. of the column packing. Also, experiments were made on the effect of other substances such as Tris, phosphate, alkaline phosphatase, and KCl on completeness of silylation. The individual impurities showed no significant effect on the relative weight response (RWR) values of nucleosides; however, when a mixture was used, significantly lower RWR values were observed for all nucleosides except thymidine when using 1000 molar excess of BSTFA greater than 1000 should be used for silylation and chromatography of nucleosides in an RNA hydrolysate. As reported earlier the best derivatization of nucleosides was achieved using closed tube silylation at 150 degrees for 15 min with 225 molar excess BSTFA and chromatography on 4% OV-11 on Supelcoport. In general, the presence of salts and other substances can be significant in quantitative work, thus it is suggested that they be removed using chromatographic cleanup methods. The stability of nucleosides as a function of concentration of HCl, at room temperature was studied and very low RWR values for nucleosides were obtained when stored for 48 h in greater than 0.001 N HCl. Trimethylsilylation of various nucleotides and dinucleotides were made at 15 min as a function of temperature, and at 150 degrees at different times...
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PMID:Derivatization and chromatography of nucleosides and nucleotides. 1 23

At least three gluconic acid forming enzymes were identified in cell-free extracts of Aspergillus niger: glucose oxidase (EC 1.1.3.4), a glucose dehydrogenase (EC 1.1.99.10), and an enzyme or a mixture of enzymes catalyzing the cleavage of 6-phosphogluconate into gluconate and inorganic phosphate. 2,6-dichlorphenolindophenol was one of the hydrogen acceptors in vitro of the glucose dehydrogenase. Some properties of this enzyme (Km values, pH-dependence, substrate and hydrogen acceptor specificity), as determined in cell-free extracts, were found to be in good agreement with properties described in literature for a glucose dehydrogenase which has been purified from Aspergillus oryzae. The formation of Pi from 6-phosphogluconate and other phosphate esters was found to have an optimum between pH 7 and 8 , and another below pH 4. This suggests that it is catalyzed by an alkaline and an acid phosphomonoesterase (EC 3.1.3.1, 3.1.3.2), both enzymes exhibiting only low substrate specificity. The influence of extraction and assay buffers on the activity of gluconate forming enzymes was investigated. Loss of activity during preparation of cell-free extracts, as calculated from loss of activity storage of cell-free extracts at 4 degrees C, was found to be lower than 4%. Purified glucose oxidase added before homogenization was found in the extract almost quantitatively.
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PMID:[Gluconic acid forming enzymes in Aspergillus niger (author's transl)]. 1 16

A repressible alkaline phosphatase has been isolated from the extreme bacterial thermophile. Thermus aquaticus, and has been purified to homogeneity as judged by disc acrylamide electrophoresis and sodium dodecyl sulfate electrophoresis. Upon investigation, the purified enzyme was shown to hydrolyze certain phosphodiesters in addition to a wide variety of phosphomonoesters. The diesters included bis-p-nitro-phenyl phosphate and thymidine 3'-monophospho-p-nitro-phenyl ester. The temperature optimum for the diesterase activity was 80--85 degrees at pH 7.2. Orthophosphate competitively inhibited both activities. Nucleotides such as AMP, ADP, and ATP also inhibited both esterase activities as did alpha-D-glucose 1-phosphate and alpha-sodium glycerol phosphate. The isoelectric point of the enzyme was determined to be 8.4.
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PMID:Repressible alkaline phosphatase from Thermus aquaticus: associated phosphodiesterase activity. 1

The synthesis of prodigiosin by non-proliferating cells of Serratia marcescens was examined in the presence of a wide range of concentrations of inorganic phosphate (Pi). A high elevation of pigment formation was obtained at less than or equal to 0.3 mM, and a broader but much lower elevation was obtained at 10 to 250 mM Pi. The synthesis of two immediate precursors of the pitment also was inhibited by Pi. The mechanism of action of Pi did not involve changes in pH or accumulation of the trace metal nutrient iron or zinc. Inhibition was most pronounced when Pi was added to the induction system before the onset of pigment formation. The inhibitor also diminished the burst of alkaline phosphatase activity that occurred in the period between the start of induction and appearance of prodigiosin.
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PMID:Phosphate inhibition of secondary metabolism in Serratia marcescens. 1 84

The absorbance of an alkaline solution of 4-nitrophenyl phosphate is a function of temperature. Quantitative evaluation of this phenomenon indicates that it (a) depends on the concentration of the compound and is independent of source, buffer concentration, and pH above 9.0; (b) is reversible; (c) is not a result of alkaline hydrolysis or 4-nitrophenol contamination; and (d) correlates with a temperature-induced shift of its absorbance spectrum. The phenomenon may represent a potential analytical problem in methods for alkaline phosphatase in which this compound is the substrate. If thermal equilibrium is not reached and maintained during an alkaline phosphatase assay, the thermochromic response will be included in the measured rate. The magnitude of this error depends on the thermal response and control characteristics of each particular instrument and the reaction conditions under which such an analysis is performed.
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PMID:Temperature dependence of the absorbance of alkaline solutions of 4-nitrophenyl phosphate--a potential source of error in the measurement of alkaline phosphatase activity. 1 64

Activities of the enzymes glutamine synthetase (EC 6.3.1.2.), glucosamine 6-phosphate acetyltransferase (EC 2.3.1.4.), uridine 5'-diphosphate (UDP)-N-acetylglucosamine pyrophosphorylase (EC 2.7.23.), UDP-N-acetylglucosamine 4-epimerase (EC 5.1.3.7.), fructose 1,6-diphosphate phosphatase (EC 3.13.11.), L-glutamine-fructose 6-phosphate transamidase (EC 5.3.1.19.), alkaline phosphatase (EC 3.1.3.1.), and malic dehydrogenase (EC 1.1.1.37) were assayed in partially purified extracts prepared at different stages of myxospore formation and germination in liquid cultures of Myxococcus xanthus. The specific activities of the first six of these enzymes increased 4.5- to 7.5-fold after 2 h of induction with 0.5 M glycerol or 0.2 M dimethyl sulfoxide. The increase in specific activities of these six enzymes was not observed in a mutant unable to be induced with glycerol. During the first 2 to 4 h of induction and during the first hour of germination, the level of these enzymes decreased to the level characteristic of vegetative cells. It is suggested that the six enzymes are responsible for the increased conversion of fructose 1,6-diphosphate to UDP-N-acetylgalactosamine, the major precursor of the myxospore coat.
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PMID:Myxospore coat synthesis in Myxococcus xanthus: enzymes associated with uridine 5'-diphosphate-N-acetylgalactosamine formation during myxospore development. 1 17

Membrane-bound alkaline phosphatase of Bacillus licheniformis 749/c is derepressed by glucose in complex and chemically defined media. In the presence of lactate, pyruvate, or succinate the synthesis is repressed. The lactate repression neither affects total protein synthesis nor inhibits penicillinase synthesis. Thus, carbon sources specifically influence alkaline phosphatase synthesis. Although variations in the inorganic phosphate content of the growth media directly affect alkaline phosphatase synthesis, the intracellular inorganic and total phosphate pools appear to be unrelated to its repression or derepression. During lactate repression there is preferential incorporation of lactate molecules into glycogen, whereas no such incorporation could be detected from glucose. Net glycogen synthesis remains the same in glucose- or lactate-grown cells. It is postulated that, in phosphate-deficient growth medium, gluconeogenic metabolism regulates alkaline phosphatase synthesis.
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PMID:Interrelationship of carbohydrate metabolism and alkaline phosphatase synthesis in Bacillus licheniformis 749/c. 1 80

The pH dependence of the human prostatic acid phosphatase-catalyzed hydrolysis of p-nitrophenyl phosphate and beta-glyceryl phosphate has been studied over a wide range of pH and the values of Km and V calculated with the aid of the Cleland HYPER program. The pH dependence of Km shows the effect of substrate ionization: pK values of 5.6 and 6.4 are observed as for the respective values of free substrates. The pH dependence of both Km and V for each substrate reveals the involvement of an ionizable group in the ES complex which is ascribed to a phosphohistidine-enzyme intermediate. The small deuterium solvent isotope effects which are observed on V are consistent with values observed for solvolysis of phosphoramidates. The measured data for Km indicates limits on burst-titration experiments of prostatic acid phosphatase (orthophosphoric-monoester phosphohydrolase, EC 3.1.3.2).
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PMID:pH dependence and solvent isotope effects in the hydrolysis of phosphomonoesters by human prostatic acid phosphatase. 2 Sep 64


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