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)

The reliability of the stainability by Trypan Blue (TB) to detect membrane damage in hepatocyte suspensions of different TB stainability and in freshly isolated cells exposed to 50 microM cadmium (Cd) for 60 min was assessed by comparison with the leakage of lactate dehydrogenase (LDH) and NADH-oxidation. The cellular nitrophenyl-phosphate (NPP) uptake and the digitonin-induced fluorescence of 8-anilinonaphthalene-sulfonate-1 (dig-ANS-F) were introduced as integrity parameters of hepatocytes and compared with TB stainability. Cd was without effect on all these parameters. LDH-leakage was a poor criterion, whereas NADH-oxidation and dig-ANS-F were as sensitive as TB stainability. The NPP-uptake was more sensitive than TB stainability to indicate toxic Cd-effects when the plasma membrane still seemed to be intact. Because of the enhanced extracellular NPP-degradation, which resulted from the release of alkaline phosphatase, NPP-uptake was useful as a measure of Cd-induced damage only under certain conditions. These results confirm TB stainability as a simple and reliable criterion for plasma membrane integrity and therefore viability of hepatocytes also in Cd-toxicity.
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PMID:Differential sensitivity of integrity criteria as indicators of cadmium-induced cell damage. 620 25

In 50 workers of a non-iron metallurgic plant exposed in their work to lead and trace amounts of cadmium and zinc cytochemical reactions were carried out in peripheral blood granulocytes. The control group comprised 30 men. In the investigations the degree of intoxication with lead compounds and the effect of the length of exposure ion the cytochemical reactions were taken into account. It was observed in these investigations that chronic exposure to lead and trace amounts of the remaining elements caused changes in the activity of acid phosphatase, alkaline phosphatase, lactic dehydrogenase and MOP. In particular, a significant fall of MOP and acid phosphatase activity and increased LDH activity in subjects exposed to lead with biochemical evidence of lead absorption deserve attention. With longer exposure to lead the activity of MPO decreased in workers with evidence of lead absorption.
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PMID:[Cytochemical studies of peripheral blood granulocytes of workers with occupational exposure to lead compounds]. 627 22

Ferritin binds a large quantity of Be2+ (Price D.J. and Joshi, J.G. J. Biol. Chem. 258 (1983) 10873) as well as other divalent metal ions. Therefore the ability of this protein to protect enzymes against or reverse the inhibition by metal ions was studied. Evidence presented here shows that the inhibition by Be2+ of the enzymes Na+K+ATPase, alkaline phosphatase and phosphoglucomutase is reversed by ferritin. Be2+ can be transferred reversibly between phosphoglucomutase and ferritin depending upon the relative concentrations of the 2 proteins. Ferritin also reactivated phosphoglucomutase inhibited by Zn2+, Cu2+, or Cd2+. Incubation of ferritin containing Be2+ with 4-10 fold molar excess of phosphoglucomutase (with respect to Be2+) removed 90% of the Be2+ from ferritin. The rates of inactivation of phosphoglucomutase by Be2+ donated by apoferritin or ferritin were identical. Based upon these observations it is suggested that Be2+ bound to the protein shell and to the iron core are in equilibrium with each other with the equilibrium favoring ferritin-Be2+ complex.
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PMID:Ferritin: protection of enzymatic activity against the inhibition by divalent metal ions in vitro. 633 Sep 34

113Cd NMR spectra of 113Cd(II)-substituted Escherichia coli alkaline phosphatase have been recorded over a range of pH values, levels of metal site occupancy, and states of phosphorylation. Under all conditions resonances attributable to cadmium specifically bound at one or more of the three pairs of metal-binding sites (A, B, and C sites) are detected. By following changes in both the 113Cd and 31P NMR spectra of 113Cd(II)2 alkaline phosphatase during and after phosphorylation, it has been possible to assign the cadmium resonance that occurs between 140 and 170 ppm to Cd(II) bound to the A or catalytic site of the enzyme and the resonance occurring between 51 and 76 ppm to Cd(II) bound to B site, which from x-ray data is located 3.9 A from the A site. The kinetics of phosphorylation show that cadmium migration from the A site of one subunit to the B site of the second subunit follows and is a consequence of phosphate binding, thus precluding the migration as a sufficient explanation for half-of-the-sites reactivity. Rather, there is evidence for subunit-subunit interaction rendering the phosphate binding sites inequivalent. Although one metal ion, at A site, is sufficient for phosphate binding and phosphorylation, the presence of a second metal ion at B site greatly enhances the rate of phosphorylation. In the absence of phosphate, occupation of the lower affinity B and C sites produces exchange broadening of the cadmium resonances. Phosphorylation abolishes this exchange modulation. Magnesium at high concentration broadens the resonances to the point of undetectability. The chemical shift of 113Cd(II) in both A and B sites (but not C site) is different depending on the state of the bound phosphate (whether covalently or noncovalently bound) and gives separate resonances for each form. Care must be taken in attributing the initial distribution of cadmium or phosphate in the reconstituted enzyme to that of the equilibrium species in samples reconstituted from apoenzyme. Both 113Cd NMR and 31P NMR show that some conformational changes consequent to metal ion or phosphate binding require several days before the final equilibrium species is formed.
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PMID:113Cd nuclear magnetic resonance of Cd(II) alkaline phosphatases. 633 52

Methods have been developed for the addition of different metal ion species to the three distinct pairs of metal sites (A, B, and C) found in the dimer of apoalkaline phosphatase. This allows the preparation of hybrid alkaline phosphatases in which A and B sites of each monomer contain two different species of metal ion or the A and B sites of one monomer contain the same species of metal ion, while the adjacent monomer contains a second species. The following hybrids have been characterized in detail: (Zn(II)ACd(II)B)2 alkaline phosphatase, (Zn(II)AMg(II)B)2 alkaline phosphatase, (Cd(II)AZn(II)B)2 alkaline phosphatase, and (Zn(II)AZn(II]B)(Cd(II)ACd(II)B) alkaline phosphatase. 31P and, where appropriate, 113Cd NMR have been used to monitor the behavior of the covalent (E-P) and noncovalent (E X P) phosphointermediates and of the A and B metal ions. From the pH dependencies of the E-P in equilibrium E X P in equilibrium E + Pi equilibria, it is clear that A site metal is the dominant influence in dephosphorylation of E-P and may have a coordinated water molecule, which ionizes to ZnOH- at a low pH providing the nucleophile for dephosphorylation. A site metal also serves to coordinate phosphate in the E X P complex. B site metal has a much smaller effect on dephosphorylation rates, although it does dramatically alter the Pi dissociation rate, which is the rate-limiting step for the native enzyme at alkaline pH, and is probably important in neutralizing the charge on the phosphoseryl residue, thus potentiating the nucleophilic attack of the OH- bound at A site. Phosphate dissociation is slowed markedly by replacement of B site zinc by cadmium. There is clear evidence for long range effects of subunit-subunit interactions, since metal ion and phosphate binding at one active center alters the environments of A and B site metal ions and phosphoserine at the other active site.
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PMID:Zn(II)-113Cd(II) and Zn(II)-Mg(II) hybrids of alkaline phosphatase. 31P and 113Cd NMR. 637 Sep 97

Orally administered cadmium has been known to cause diarrhea and flatulence of the gastrointestinal tract. Scanning electron microscopic observations revealed that the absorptive cells on the tip of the intestinal villi were affected to some extent by administration of 2.5 microgram CdSO4/10 g of body weight (b. w.). Administration of higher doses of CdSO4 made the microvilli of the absorptive cells sparse and caused degeneration of the cells. Strong enzymic activities of alkaline phosphatase, acid phosphatase, magnesium-dependent ATPase, and sodium-potassium-dependent ATPase were recognized at the microvilli of the absorptive cells of the villi in the control mice. The enzymic activities of magnesium-dependent ATPase and sodium-potassium-dependent ATPase became weak with increasing dosages of CdSO4. The microvilli of the absorptive cells showed a strong alkaline phosphatase activity at a dose less than 25 microgram CdSO4/10 g of b. w., while some inhibitory effects could be recognized with 50 microgram/10 g of b. w. After administration of 2.5 microgram CdSO4/10 g of b. w., no acid phosphatase reaction products were found only at the absorptive cells located on the tip of the villi. Administration of a large quantity more than 5 microgram/10 g of b. w. strongly affected the acid phosphatase activity. It may be possible that the digestive functions are impaired by low cadmium administration.
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PMID:Scanning electron microscopic and enzyme histochemical observations on the cadmium-affected gastrointestinal villi of mice. 645 14

The effect of nickel on cadmium nephro-toxicity and hepato-toxicity in rats was investigated. The administration of nickel (6 mg per kg, i.p., three days) or cadmium (6 mg per kg, i.m., once) significantly enhanced the urinary excretion of alkaline phosphatase (ALP), lactate dehydrogenase (LDH), glutamate oxaloacetate transaminase (GOT), amino acids, and proteins. In addition, it increased the activity of serum ALP, GOT, and glutamate pyruvate transaminase (GPT). These biochemical alterations in urine and serum were used as a measure of kidney and liver damage. Cadmium-induced enzymuria, proteinuria, amino aciduria and increase in the activity of serum enzymes were significantly less marked in animals pretreated with nickel than in controls. However, the accumulation of cadmium in kidneys and liver and its urinary excretion were unaffected by nickel pretreatment. The results suggest protection by nickel against cadmium nephro- and hepato-toxicity.
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PMID:Preventive effects of nickel on cadmium hepatotoxicity and nephrotoxicity. 647 83

Boar sperm plasma membranes were purified by differential and sucrose density equilibrium centrifugation and were found to yield a single band at a density of 1.14 g/cm3. Both alkaline and acid phosphatase activities were enriched in this fraction. The alkaline phosphatase activity was optimal in 100 mM tris (hydroxymethyl) methylamine (Tris)-NaHCO3 at pH 9.9 with 0.05% Triton X-100 and 1 mM MgCl2. This activity was inhibited by ethylenediaminetetraacetic acid (EDTA), cadmium, zinc or heating at 60 degrees C for 30 min. Also, L-homoarginine caused approximately 70% inhibition and L-phenylalanine or L-leucine caused about 10 to 20% inhibition. Acid phosphatase activity was optimal in 100 mM sodium acetate at pH 5.1 with 0.05% Triton. Sodium dodecyl sulfate, potassium fluoride (KF) or sulfhydryl reagents inhibited the activity, while EDTA or heating at 60 degrees C had no effect. These data for enzymes from boar sperm plasma membranes can be used for future work on the quantitation of the enzymes, distinguishing these two phosphatases from other phosphohydrolases, purification of the enzymes and for comparison to phosphatases in other tissues.
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PMID:Some properties of acid and alkaline phosphates from boar sperm plasma membranes. 650 37

Alkaline phosphatase, confined to myoepithelial cells and blood capillaries in rat submandibular salivary gland (SSG), may participate in the regulation of salivary flow. To determine whether the alkaline phosphatase of SSG has unique properties, comparative kinetic and inhibition studies on enzymes from SSG, intestine and kidney were performed. The Km values (at optimal pH for each tissue) of 0.34, 0.55 and 0.49 mM with p-nitrophenylphosphate for the enzymes from SSG, kidney and small intestine respectively were similar. However, in the presence of cadmium the Ki values of 0.08 and 0.12 microM for the enzymes from SSG and kidney respectively were different from the value of 1.86 microM for the enzyme from small intestine. Differences in Ki values suggest differences in biochemical properties between the enzyme from small intestine and that isolated from SSG or kidney.
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PMID:A kinetic study of rat salivary gland alkaline phosphatase and its inhibition by cadmium. 657 7

The purpose of this experiment was to compare the toxic effects of aflatoxin B1 (AFB1) and warfarin in pigs and to determine whether these have an additive effect in these pigs fed dietary Cd. Cadmium was provided daily through the diets of 2 concentrations (0 or control, and 83 micrograms/g of diet) during the 40 days of the experiment. At the start of the 5th week, AFB1 and warfarin were given in 5 daily doses (each dose 0.2 mg/kg of body weight) and the effects were determined for 10 days (starting with the 1st treatment day). Aflatoxin B1 given to the pigs fed the control diet (0 Cd) was toxic, inducing significantly increased alkaline phosphatase, sorbitol dehydrogenase, and aspartate aminotransferase activities and the prothrombin time (PT) and activated partial thromboplastin time (APTT) and significantly decreased values in serum total protein, alpha-globulin, beta-globulin, gamma-globulin, and fibrinogen. There was no effect on blood urea nitrogen. The treatment with warfarin was more effective in producing earlier and significantly longer PT and APTT. In the pigs fed the diet with the added Cd, differences in activity of alkaline phosphatase, sorbitol dehydrogenase, aspartate aminotransferase values, but not blood urea nitrogen, as well as differences in intensity and duration of response in PT and APTT occurred when pigs were dosed daily for 5 days after AFB1 or warfarin. It is concluded that dietary Cd (83 micrograms/g of diet) in young pigs has an inhibitory effect on AFB1 toxicity and an enhancing synergistic effect with warfarin.
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PMID:Toxicology of aflatoxin B1, warfarin, and cadmium in young pigs: clinical chemistry and blood coagulation. 680 74


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