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)

In active odontoblasts from the rat incisor, used as a model system for biologic calcification, two distinguishable enzyme activities capable of degrading adenosine monophosphate (ATP) exist. Once can be inhibited ny 1-tetramisole, (+/-)-2,3,5,6,-tetrahydro-6-phenylimidazo (2.1B) THIAZOLE HYDROCHLORIDE (Levamisol) and (+/-)-6(m-bromophenyl)-5.6-dehydroimidazo (2.1-b) thiazole oxalate (R823) and is probably identical with nonspecific alkaline phosphatase (EC 3.1.3.1). The activity of the other enzyme, named Ca2+-ATPase, is dependent on the presence of Ca2+ or Mg2+ and is activated by these ions. The pH optimum of Ca2+-ATPase is 9.8. The Ca2+-ATPase is unaffected by Levamisole, R 8231, ouabain, ruthenium red, Na+ and K+ ions. Maximal activity was found against ATP, whereas adenosine diphosphate, guanosine triphosphate, inosine triphosphate and adensoine monophosphate were hydrolysed at lower rate. It may be speculated that the Ca2+-ATPase is concerned with the transmembranous transport of Ca2+ ions to the mineralization front.
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PMID:A comparison of ATP-degrading enzyme activities in rat incisor odontoblasts. 0 54

Purified chondrocytic alkaline phosphatase (orthophosphoric-monoester phosphohydrolase (alkaline optimum), EC 3.1.3.1) from bovine fetal epiphyseal cartilage hydrolyzes a variety of phosphate esters as well as ATP and inorganic pyrophosphate. Optimal activities for p-nitrophenyl phosphate, ATP and inorganic pyrophosphate are found at pH 10.5, 10.0 and 8.5, respectively. The latter two substrates exhibit substrate inhibition at high concentrations. p-Nitrophenyl phosphate demonstrates decreasing pH optima with decreasng substrate concentration. Heat inactivation studies indicate that both phosphorolytic and pyrophosphorolytic cleavage occur at the same site on the enzyme. Mg2+ (0.1-10.0 mM) and Mn2+ (0.01-0.1 mM) show a small stimulation of p-nitrophenyl phosphate-splitting activity at pH 10.5. Levamisole, Pi, CN-, Zn2+ and L-phenylalanine are all reversible inhibitors of the phosphomonoesterase activity. Pi is a competitive inhibitor with a Ki of 10.0 mM. Levamisole and Zn2+ are potent non-competitive inhibitors with inhibition constants of 0.05 and 0.04 mM, respectively. The chondrocytic alkaline phosphatase is inhibited irreversibly by Be2+, EDTA, EGTA, ethane-1-hydroxydiphosphonate, dichloromethane diphosphonate, L-cysteine, phenyl-methylsulfonyl fluoride, N-ethylmaleimide and iodoacetamide. NaCL, KCL and Na2SO4 at 0.5-1.0 M inhibit the enzyme. At pH 8.5, the cleavage of inorganic pyrophosphate (pyrophosphate phosphohydrolase, EC 3.6.1.1) by the chondrocytic enzyme is slightly enhanced by low levels of Mg2+ and depressed by concentrations higher than 1mM. Ca2+ show only inhibition. Similar effects of Mg2+ and Ca2+ on the associated ATPase (ATP phosphohydrolase, EC 3.1.6.3) activity were observed. Arrhenius studies using p-nitrophenyl phosphate and AMP as substrates have accounted for the ten-fold difference in V in terms of small differences in both the enthalpies and entropies of activation which are 700 cal/mol and 2.3 cal/degree per mol, respectively.
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PMID:Enzymatic characterization of the chondrocytic alkaline phosphatase isolated from bovine fetal epiphyseal cartilage. 4 Jun 3

Potassium-stimulated p-nitrophenylphosphatase (K+-pNPPase) activity was investigated in rat somatosensory cortex where 64-88% of enzymatic activity survived 5-10 min of fixation with 3% formaldehyde in 0.1 M cacodylate buffer, pH 7.4. Potassium-stimulated activity was inhibited by 1-10 mM ouabain. Levamisole (1.7 mM) inhibited brain alkaline phosphatase activity, facilitating the detection of K+-pNPPase activity. Strontium (10-20 mM) inhibited enzymatic activity by 38-75%. In parallel histochemical studies reaction product was found in strata, with cortical layers 2, 3, 4 and the outer portion of 5 containing the heaviest deposits. Highly reactive, vertically oriented, large diameter fibers were seen as groups between the outer portion of layer 5 and the pail surface. These fibers apparently arborize in the superficial layers. Smaller fibers were also positive and were oriented in various planes. The highest density of smaller, positive fibers occurred in layers 2 through 5. All positive fibers appeared to be axons or dendrites. Reaction product was not heavily concentrated in neuron perikarya or in glial elements. Sections did not contain reaction product when incubated in media lacking K+ or containing ouabain. The convergence of data from parallel histochemical and biochemical approaches supports the conclusion that the reactivity localized in the cerebral cortex represented the site of K+-pNPPase, a known component of the Na+,K+-adenosine triphosphatase complex. Neuronal processes demonstrated the highest enzymatic activity and may be most important in the active transport of Na+ and K+ in somatosensory cortex.
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PMID:Histochemical localization of potassium-stimulated P-nitrophenylphosphatase activity in the somatosensory cortex of the rat. 18 89

A novel alkaline phosphatase differing from the so-called liver-specific isoenzyme was found in four out of twenty-four normal adult livers. Although the mobility of this enzyme was the same as that of so-called liver-specific alkaline phosphatase on the polyacrylamide gel electrophoretogram, its mobility was not altered following neuraminidase treatment, while that of the liver-specific enzyme was affected by the same treatment. Both enzymes also differed in other enzymatic and immunologic properties. The enzyme, however, resembled the so-called intestinal alkaline phosphatase in many enzymatic and immunologic properties. Thus, the inhibition patterns by amino acids, EDTA and inorganic phosphate, the pH optima, KM values for phenyl phosphate and reactivity with anti-intestinal alkaline phosphatase antibody were quite similar for both enzymes. Differences in the properties of this enzyme and intestinal alkaline phosphatase were in sensitivity to denaturation by treatment with heat and urea and to inhibition by Levamisole. The possible origin of the enzyme in normal liver and its relationship to the Kasahara isoenzyme and fetal intestine-type in hepatoma is discussed.
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PMID:A novel alkaline phosphatase, a minor component of normal liver phosphatases. 20 20

The organelle pathology of neutrophils in chronic granulocytic leukaemia (CGL) was investigated by analytical subcellular fractionation. There were minor reductions in activity of some granule enzymes with an abnormal distribution in sucrose density gradients of the specific granules. There was a marked reduction of 5'-nucleotidase activity but this is probably related to the relative reduction of the mononuclear cell contamination of the neutrophils isolated from leukaemic patients compared with controls. Another plasma membrane enzyme, NADH-nitroblue tetrazolium reductase, which has a microbicidal role, had increased activity. Neutrophils from patients with CGL had 13% the alkaline phosphatase activity of controls and were compared with neutrophils from women in the third trimester of pregnancy when the activity was increased to 8 times the control level. The latent activity, per cent inhibition by Levamisole, kinetic constants and subcellular distribution of alkaline phosphatase were similar in the three groups. It is suggested that the properties and intracellular localization of alkaline phosphatase are normal in CGL and that there is a quantitative lack of enzyme.
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PMID:Studies on the subcellular organelles of neutrophils in chronic granulocytic leukaemia with special reference to alkaline phosphatase. 28 20

By recording the incubation time needed for initial appearance of the red and blue formazans the reliability of the histochemical method for 3beta-HSD was investigated: 1. Prefixation of small tissue blocks with 1% W/V methanol-free formaldehyde (pH=7.2) for up to 30 min preserved morphological integrity as well as maximal enzyme activity. Moreover, the substantivity of formazans and lipids was enhanced. 2. Commercial available glutaraldehyde (pH=7.2) induced SH groups in the tissue (even at 0.1% W/V for 5 min) thereby enhancing the Nothing dehydrogenase reaction. 3. Preextraction of lipids with acetone for 20 min at -30 degree C caused no loss of activity and was an inevitable step if a reliable activity pattern had to be achieved (e.g. in interstitial cells). 4. No diffusion of enzyme was noticed within 30 min of preincubation in phosphate buffer (0.2 M, pH=7.2) at 20 degree C. 5. By using the double-section incubation method no diffusion of 3beta-HSD or rediffusion of NADH or PMSH could be noticed withn 45 min of incubation, provided that low concentrations of NAD (0.1 mg/ml) and PMS (0.003 mg/ml) were balanced against the concentration of Nitro BT (0.5 mg/ml) or Tetranitro BT (1.0mg/ml). 6. The utlity of different inhibitors of alkaline phosphomonoesterase was tested and discussed. 7. By inhibiting alkaline phosphomonoesterase with 0.1 mM of L-p-bromotetramisole or 16 mM of beta-glycerophosphate, 3beta-HSD was shown to be exclusively NAD-linked. 8. Levamisole was a potent inhibitor of NADH-tetrazolium reductase as well as 3 beta-HSD, but not of NADPH-tetrazolium reductase. 9. 3beta-HSD possess SH groups requisite for the activity as this enzyme was totally inhibited by N-ethyl maleimide. 10. Whether alcohol dehydrogenases may use steroids as substrate is discussed; It is concluded that preextraction (by acetone) and/or the use of an inhibitor of alcohol dehydrogenase (1,10-phenanthroline) has to be performed. 11. Propylene glycol was a poor solvent for all substrates and was itself an excellent substrate for alcohol dehydrogenase. 12. Specifications for the ideal solvent of steroid substrates in the histochemical practice are proposed. DMSO showed to be promising as a steroid solvent (e.g. extraction of formazans was considerably lower as compared to DMF). 13. The utilization of substrates was descending in the following order (using 1 mM and 0.1 ml/ml of either DMF or DMSO): epiandrosterone, methandriol, dehydroepiandrosterone and pregnenolone. 14. If DMSO was used as solvent for pregnenolone (but not for the other substrates tested) an evident increase of activity was recorded as compared to DMF.
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PMID:Histochemistry of 3beta-hydroxysteroid dehydrogenase in rat ovary. I. Amethodological study. 55 64

In electron microscope cytochemical studies alkaline phosphatase activity was present in the mitochondria of all liver cells and associated with the plasma membrane of the cells of bile canaliculi. The mitochondrial activity was partially inhibited by L-phenylalanine and Levamisole but the plasma membrane associated activity was completely inhibited by Levamisole. Biochemical assays have shown that a significant amount of the total mouse liver alkaline phosphatase activity was present in the mitochondria fraction. Starch gel electrophoresis showed that this mitochondrial alkaline phosphatase had a characteristic isoenzyme pattern, consisting of 3 distinct bands which were not retarded by neuraminidase treatment. The enzyme in the mitochondria-free supernatant showed one wide band which was retarded by neuraminidase.
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PMID:Alkaline phosphatase in mitochondria. 61 Aug 69

The cellular localization and isoenzyme pattern of alkaline phosphatase in five cell lines derived from human bladder carcinomas (T24, RT4, RT112, J82, EJ) shown not to be HeLa cells has been established. RT112 cells had a high level of alkaline phosphatase. RT4 had a moderate amount of alkaline phosphatase but in the other three lines, levels were extremely low. Prednisolone caused a small (2 to 3-fold) increase in total alkaline phosphatase in T24 and RT112 lines only. Electrophoretic separation of isoenzymes showed that RT112 and RT4 cells (derived from more highly differentiated tumor types) had three heat stable bands equivalent to placental alkaline phosphatase and three slower bands of a modified placental type. Prednisolone increased only the former. In T24 cells the enzyme resembled the liver-type alkaline phosphatase in electrophoretic mobility and sensitivity to heat denaturation. Cytochemical studies confirmed the presence of cell surface-associated extramembraneous placental type enzyme in RT112 cells. All five cell lines had small deposits of intramembraneous alkaline phosphatase in the plasma membrane and deposits associated tith the mitochondrial membranes and the endoplasmic reticulum that were not completely inhibited by phenylalanine or Levamisole.
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PMID:Alkaline phosphatase activity in human bladder tumor cell lines. 87 May 58

In this light microscopic study, the inhibitory effect of levamisole on the alkaline phosphatase of equine, bovine and rat neutrophilic leukocytes was examined histochemically, using 0.05, 0.1 and 0.5 mM levamisole in the incubation mixture. Levamisole proved to be a potent inhibitor of neutrophilic alkaline phasphatase already at very low concentrations. Statistically significant differences in the rate of inhibition of the enzyme were found between the species examined. Some observations of the eosinophils were also made; equine eosinophils were found to be considerably resistant towards alkaline phosphatase inhibition with levamisole at the concentrations used.
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PMID:Inhibition of the alkaline phosphatase of equine, bovine and rat neutrophilic leukocytes with levamisole at low concentrations. 121 42

1. Alkaline phosphatase is covalently bound to bovine mammary microsomal membranes and milk fat globule membranes through linkage to phosphatidylinositol as demonstrated by the release of alkaline phosphatase following treatment with phosphatidylinositol-specific phospholipase C. 2. The release of alkaline phosphatase from the pellet to the supernatant was demonstrated by enzyme assays and electrophoresis. 3. Electrophoresis of the solubilized enzymes showed that the alkaline phosphatase of the microsomal membranes contained several isozymes, while only one band with alkaline phosphatase activity was seen in the fat globule membrane. 4. Levamisole and homoarginine were potent inhibitors of the alkaline phosphatase activities in both membrane preparations and in bovine liver alkaline phosphatase, but not in calf intestinal alkaline phosphatase.
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PMID:Alkaline phosphatase in the lactating bovine mammary gland and the milk fat globule membrane. Release by phosphatidylinositol-specific phospholipase C. 137 15


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