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)

This study demonstrates the changes of concentration and elimination of calcium, phosphate and zinc, as well as alteration of serum alkaline phosphatase and acid phosphatase especially in patients with severe brain injuries in connection with bone fractures. Because the study has not been completed, the presently acquired results should only demonstrate possible development of the examined parameters. To find out the pathogenesis of overgrowing callus in brain-injured patients, further examinations are being carried out to find the histochemical activities of alkaline and acid phosphatase, lactate dehydrogenase, adenosine triphosphatase and acetylcholine esterase.
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PMID:[Special aspects of fracture healing in cranio-cerebral injuries]. 72 99

Alkaline phosphatase of Escherichia coli, isolated by procedures which do not alter its intrinsic metal content, contains 1.3 +/- 0.3 g-atom(s) of magnesium and 4.0 +/- 0.2 g-atoms of zinc per mol of molecular weight 89 000 (Bosron et al., 1975). Substitution of Co(II) for Zn(II) and/or Mg(II) results in spectral properties which can be correlated with enzymatic activity. Magnesium does not activate the apoenzyme but augments the activity of 2-Co(II) enzyme almost 3-fold and that of the 4-Co(II) enzyme 1.3-fold. The magnesium-induced increase in activity of the 2-Co(II) enzyme is accompanied by spectral changes which are consistent with an alteration from largely octahedral-like to pentacoordinate-like coordination geometry. Magnesium increases the intensity of the absorption and magnetic circular dichroism (MCD) signals of the 4-Co(II) enzyme but without evidence of changes in coordination geometry. Cobalt when bound to the magnesium sites results in octahedral-like EPR spectra, unperturbed by phosphate which significantly affects cobalt at the pentacoordinate-like sites. In the absence of magnesium, 6 g-atoms of cobalt are required to maximize the spectral properties, but activity does not increase further after the addition of only 4 g-atoms of cobalt, while activity is optimal with only 2 g-atoms of cobalt. Hydrogen-tritium exchange measurements indicate that magnesium also stabilizes the dynamic structural properties of the apo- and 2-Co(II) enzymes but has little effect on the structure of 4-Co(II) phosphatase. The response to magnesium of both the spectral properties and enzymatic activities of cobalt alkaline phosphatase demonstrates that magnesium regulates cobalt (and zinc) binding and modulates the activity of the resultant products.
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PMID:The effect of Mg(II) on the spectral properties of Co(II) alkaline phosphatase. 78 21

Immunogenic and antigenic properties of a Zn2+ -deficient alkaline phosphatase produced in a mutant (U-47) of Escherichia coli have been studied. The native U-47 enzyme, that exists in a monomerdimer equilibrium, was used as immunogen. From the antisera obtained, four antibody populations directed to the various molecular forms of U-47 enzyme have been purified by affinity chromatography using specific antigens coupled to glutaraldehyde-activated beads of indubiose. 70% of the total antibody obtained was directed both to the monomeric and the dimeric forms, 9% was directed to the dimer but showed a low affinity for the monomer; 10% and 11% were specifically directed respectively to the monomer and the dimer. Each antibody population purified had a specific effect on the catalytic activity of the Zn2+ -activated U-47 enzyme. The anti-monomer-dimer and the anti-dimer-monomer inhibit to the same extent whereas the specific anti-monomer does not alter the activity significantly and the specific anti-dimer causes a 30% activation. The catalytic activity of the alkaline phosphatase produced in wild-type strains was also reduced by these anti-U-47 enzyme antibodies. However, whereas the anti-monomer had again very little effect, the anti-dimer-monomer and the anti-monomer-dimer inhibited this enzyme to different extents. The specific antidimer also inhibited this wild-type alkaline phosphate. Antibodies of high affinity to the dimeric form of U-47 enzyme, i.e. specific anti-dimer or anti-dimer-monomer, caused a 30% activation when they were added prior to the reactivation process by Zn2+. Specific anti-monomer strongly inhibited this reactivation process. The Fab fragment of the anti-wild-type phosphatase antibody, under the same conditions, caused a 300% activation. The extents of interactions of the various molecular forms of U-47 enzyme and of the wild-type enzyme with the anti-monomer-dimer and with the anti-dimer have been determined. U-47 enzyme monomeric form has three determinants exposed and the dimeric form has five determinants exposed for interacting with the anti-monomer-dimer antibody, the free wild-type enzyme has only two determinants exposed to this antibody. These determinants might be close to the active site or in another critical location since this antibody can reduce the catalytic activity of the wild-type enzyme to half the original value. The anti-dimer antibodies can interact with three determinants exposed at the surface of the free Zn2+ -reactivated U-47 enzyme and the non-covalent binding of one mole of inorganic phosphate results in the exposure of one more antigenic determinant.
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PMID:Effects of antibodies to various molecular forms of a mutationally altered Escherichia coli alkaline phosphatase on its activation by zinc. 78 17

A randomized, double blind crossover study of the effects of zinc sulfate and placebo was carried out in 106 patients with taste and smell dysfunction secondary to a variety of etiological factors. In the patient group prior to treatment, mean serum zinc concentration and leukocyte alkaline phosphatase activity were significantly lower than normal. Results indicate that zinc sulfate was effectively equivalent to placebo in the treatment of these disorders. Although these results demonstrate abnormalities of zinc metabolism in some patients with taste and smell dysfunction they fail to provide evidence for a single, therapeutic approach to the many disorders which are associated with abnormalities of taste and smell. However, the methods and procedures developed in this study demonstrate that taste and smell dysfunction can be studied in a quantitative, systematic manner.
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PMID:A double blind study of the effects of zinc sulfate on taste and smell dysfunction. 79 59

Alkaline phosphatase from Pseudomonas fluorescens has been partially purified. Labelled 65ZnCl2 in the culture medium is incorporated in the most purified preparations. The enzyme shows a pH optimum of 7.2-7.5 and a Km value for p-nitrophenyl phosphate of 1 times 10(-4). Zinc ions at high concentration inhibit enzyme activity. The protective effect of Mg on the inactivation of alkaline phosphatase by heat is also reported.
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PMID:Metabolic studies with 65Zn. X. Biosynthesis of alkaline phosphatase in cultures of Pseudomonas fluorescens. 80 38

Lead ions can interact with calf intestine alkaline phosphatase. Experiments using 203Pb-labeled Pb2+ ions showed that Pb2+ ions bind the native protein in a molar ratio of Pb/protein of 1:5 with moderate inhibition of its biochemical activity. The 4 g-atoms of Zn per mol present in the native enzyme may be removed by dialysis against EDTA. The inactive apoenzyme is capable of incorporating Pb2+ ions in a Pb/protein molar ratio of 2:1, giving a lead-protein complex still enzymatically active also when genetic material, such as nucleotides or DNA, has been used a a substrate. The reconstituted lead-protein is capable of binding Zn2+ ions without any release of the Pb2+ ions and with an increase in the catalytic activity of only 10-15%. The absence of Zn in the inactive apoenzyme as well as in the reconstituted lead-protein, the incorporation of Pb2+ ions in stoichiometric amounts in the apoenzyme, and the weak influence of the Zn2+ ions on the enzymatic assay of the lead-enzyme suggest that lead ions partially reactivate the calf intestine alkaline phosphatase apoenzyme.
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PMID:Replacement of metal in metalloenzymes. A lead-alkaline phosphatase. 81 61

Metal ion-complexing agents, like KCN, EDTA etc., inactivate alkaline phosphatase of pig kidney. This inactivation is reversible at low concentrations of the complexing agents and irreversible at high concentrations. The reversible inhibition is probably due to removal of Zn2+ ions from the active site, where they are necessary for catalytic action, whereas the irreversible inhibition results from the removal of Zn2+ ions necessary for preservation of the structure. The inactivation is pseudo-first order. It depends on the concentration, size and charge of the complexing agents. Beta-Glycerophosphate and Mg2+ ions protect the enzyme from inactivation by complexing agents. Quantitative examination of the effect of substrate leads to a model that is similar to the "sequential model" proposed by D.E. Koshland, G. Nemethy & D. Filmer (1966) (Biochemistry 5, 365-385) to explain allosteric behavior of enzymes. It describes the sequential addition of two substrate molecules at two active centres of the dimer enzyme. The binding of the substrate molecules is accompanied by changes in the conformation, which lead to stabilization of the enzyme against attack by complexing agents.
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PMID:Influence of complexing agents on stability and activity. 81 4

Polyacrylamide gel electrophoresis was used to characterize the isoenzymes of serum alkaline phosphatase in the rat. The electrophoresis of serum from normal rats resulted in two bands of alkaline phosphatase activity. A prominent band in serum corresponded in electrophoretic mobility to the alkaline phosphatase from bone and intestinal tissue extracts and also a slower migrating liver isoenzyme. A less prominent, fast migrating band in serum had a mobility similar to a faster migrating liver tissue extract isoenzyme. This band only represented 1-2% of the total alkaline phosphatase present in the serum of normal rats but approximately 15% of the total alkaline phosphatase in the serum of rats fed excess levels of zinc. The study also revealed an alteration in the electrophoretic mobility of alkaline phosphatase in bone homogenate by the addition of deactivated serum to the homogenate. The addition of deactivated serum did not alter the electrophoretic mobility of the liver and intestinal alkaline phosphatases in rats.
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PMID:Electrophoretic studies on alkaline phosphatases in normal and zinc intoxicated rats. 83 93

Forty 100 g male rats were fed, in groups of eight, either 0, 5, or 25 ppm cadmium in a purified diet for 14 wk. Three groups were fed each of the levels of cadmium on an ad libitum basis. Two other groups were fed either 0 or 5 ppm cadmium in amounts that were equalized to that consumed by the 25 ppm group fed ad libitum. Cadmium ingestion decreased daily diet consumption, weight gain, and terminal body weight. These parameters were not significantly different in rats whose diet consumption was equalized. Packed cell volume and serum iron as well as serum zinc were decreased in the rats fed 25 ppm cadmium. These effects were not related to diet intake. No major differences were observed in serum ceruloplasmin, glucose, protein, leucine aminopeptidase activity, or copper in any of the groups. Blood urea nitrogen and renal leucine aminopeptidase activity were decreased by cadmium ingestion in the rats fed ad libitum only. In contrast, serum alkaline phosphatase activity was elevated by cadmium in the equalized-intake groups only. Cadmium and zinc concentrations were elevated and the iron concentration was decreased in the kidney, liver, and intestinal mucosa of the cadmium-fed rats irrespective of level of diet consumption. The increased uptake of cadmium in these tissues was coincident with the increased content of the cadmium-binding protein, metallothionein, in the cytosol fraction. The results indicate that some parameters of chronic cadmium toxicity are associated with diet consumption whereas others are not.
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PMID:Biomedical responses of rats to chronic exposure to dietary cadmium fed in ad libitum and equalized regimes. 85 45

Human serum incubated with 2-amino-2-methyl-1-propanol (860 mmol/liter) and magnesium ion (270 mumol/liter) at pH 10.35 showed greater alkaline phosphatase (EC 3.1.3.1) activity than if an equal amount of magnesium ion was added at the time of measurement. The apparent increase is due in part to a slight lability of serum alkaline phosphatase in 2-amino-2-methyl-1-propanol, which is prevented by the inclusion of magnesium. For some sera, however, a portion of this increased activity is real rather than artifactual. Use of serum rather than 4-nitrophenylphosphate to initiate the reaction produced relatively low activities and, in some cases, markedly nonlinear (increasing) rate progress curves. The behavior of some commercial lyophilized control sera differed significantly from that of patients' sera, in particular exhibiting a marked lability in the presence of 2-amino-2-methyl-1-propanol. Incubation of these labile materials with Mg2+ slightly improved their stability; addition of Zn2+ plus Mg2+ markedly stimulated and completely protected their alkaline phosphatase activity.
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PMID:Effect of incubation with Mg2+ on the measurement of alkaline phosphatase activity. 90 17


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