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)

One component, the i form, of acid phosphatase (orthophosphoric-monoester phosphohydrolase (acid optimum), EC 3.1.3.2) produced by Aspergillus niger was purified from the mycelial extract. The purified enzyme was homogenous on Sephadex G-200 gel filtration, disc electrophoresis and heat inactivation. The purified enzyme was studied and the following results were obtained: 1. The enzyme catalyzed the hydrolysis of a wide variety of phosphomonoesters, but not that of bis(p-nitrophenyl)phosphate, adenosine 3',5'-cyclic monophosphate, fructose 1,6-diphosphate, adenosine 5'-diphosphate or adenosine 5'-triphosphate. 2. Fluoride, orthophosphate, arsenate, borate, molybdate and (+)-tartrate acted as inhibitors. This enzyme was inactivated by N-bromosuccinimide and 2-hydroxy-5-nitrobenzyl bromide, and was not affected by p-chloromercuribenzoate, N-acetylimidazole, p-diazobenzenesulfonic acid and tetranitromethane. From these results, tryptophan was estimated to play an important role in the enzyme activity. 3. The apparent molecular weight was 310000 by Sephadex G-200 gel filtration. Polyacrylamide gel electrophoresis in the presence of sodium dodecyl sulfate suggested that the molecular weight of the subunit was approximately 89000. 4. The purified enzyme contained 29% carbohydrate consisting of glucosamine, mannose and galactose. The amino acid composition of this enzyme was not specific compared with other known acid phosphatases.
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PMID:Purification and properties of one component of acid phosphatase produced by Aspergillus niger. 1 43

Midgut glands of abalone Haliotis discus contained two acid phosphatases [orthophosphoric-monoester phosphohydrolase (acid optimum), EC 3.1.3.2] separable by phosphocellulose column chromatography. They were designated as acid phosphatases I and II in order of elution and were purified 99- and 290-fold, respectively. Purified acid phosphatase II was nearly homogeneous as judged by polyacrylamide gel electrophoresis. The substrate specificity of acid phosphatase I was narrow, whereas that of acid phosphatase II was broad. Good substrates for acid phosphatase I included p-nitrophenyl phosphate, phosphoenolpyruvate, inorganic pyrophosphate, and nucleoside di- and triphosphates. The acid phosphatases did not require any metal ion for maximum activity and were inhibited by Zn2+, Cu2+ and Hg2+. Fluoride and arsenate were potent inhibitors of both enzymes. The pH optima of acid phosphatases I and II were 5.9 and 5.5, respectively. The molecular weights of acid phosphatases I and II were estimated to be 28,000 and 100,000, respectively, by gel filtration on Sephadex G-100. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis suggested that acid phosphatase II consists of two identical subunits.
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PMID:Purification and properties of two acid phosphatases from midgut glands of abalone Haliotis discus. 40 32

The effect of anions on the thermodynamic activation functions for a model enzyme, calf intestinal alkaline phosphatase (EC 3.1.3.1), have been studied in order to examine the role of protein hydration changes in establishing the energetics of enzyme catalysis. The influences of these anions on the activation volume (delta V) and activation free energy (delta G) reflected clear Hofmeister (lyotropic) series effects, in the order F- greater than Cl- greater than Br- greater than I- (order of increasing salting-out potential). A pronounced covariation was observed between the influences of these anions on Vmax, which is proportional to delta G, and on the negative activation volume of the reaction. Fluoride was able to counteract the influences of Br- and I- on both Vmax and delta V when combinations of these anions were employed. The effects of Br- and I- on Vmax and delta V were more pronounced at lower temperatures. The control delta V was increasingly negative at reduced temperatures. The effects of the neutral salts and propanol on delta V and delta G, as well as the effects of salting-in anions on the activation enthalpy and the negative activation entropy of the reaction, are consistent with a model which proposes that peptide groups or polar side chains on the native enzyme exergonically increase their exposure to solvent during the catalytic activation event. These conclusions are in accord with the known free energy, enthalpy, entropy, and volume changes which occur when model peptide groups are transferred between water and concentrated salt solutions. Consistent with the kinetic results, the fluorescence emission wavelength maximum of alkaline phosphatase increased in the presence of anions in the order F- greater than Cl- greater than Br- greater than I-. The salting-out ion (F-) and the salting-in ions (Br- and I-) shifted lambda max in different directions, and these lambda max shifts could be counterbalanced by using equimolar combinations of salting-in and salting-out anions. Control experiments with a model compound, N-acetyltryptophanamide, showed that the spectra shifts caused by the salts did not result solely from differential quenching by the anions of the solvent-exposed tryptophan(s) on the enzyme. Hofmeister additivity phenomena indicated that the solvent is at the basis of these salt-induced enzyme structural changes. It is concluded that changes in protein solvation during enzymic reactions contribute significantly to the thermodynamic activation parameters in both the native and the salt-perturbed enzyme.
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PMID:Effects of anions on the activation thermodynamics and fluorescence emission spectrum of alkaline phosphatase: evidence for enzyme hydration changes during catalysis. 51 38

Fluoride added to drinking water at concentrattions of 50 and 70 ppm provided highly significant increases in the ascorbic acid concentration in tissues but was without effect on the serum alkaline phosphatase and cholesterol.
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PMID:The influence of ingested fluoride on the ascorbic acid concentration in guinea-pig tissues. 63 30

Fluoride concentrations in plasma 3 hr after a single oral dose of NaF (5 mg/100 g body weight) were increased 26 times above the control, but the concentrations in erythrocytes and red cell membranes were increased only 1.8 and 1.5 times over the respective control levels. Ionic concentrations of magnesium and calcium in erythrocytes and their membranes were significantly changed by fluoride administration, but the ionic concentrations in plasma were not statistically changed in comparison with controls. Acid phosphatase activities in plasma and erythrocytes were significantly decreased by fluoride administration, but alkaline phosphatase activity in the plasma was not changed. Mg2+-activated ATPase activity was significantly elevated in the erythrocyte membrane by fluoride administration; (Na+ + K+)-activated ATPase activity was significantly decreased in the membrane.
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PMID:Changes of ion mobilizations and their related enzyme activities in the blood of fluoride-intoxicated rats. 101 Dec 89

To evaluate whether treatment with a mitogenic agent may increase bone formation and bone mass in osteopenia induced by estrogen deficiency, we determined the effect of oral fluoride treatment on bone and bone cells in ovariectomized rats. Sodium fluoride (NaF) was administered to 3-month-old ovariectomized rats 1 day after ovariectomy (OVX) for 1, 3, and 6 months. NaF was given in drinking water at the dose of 1 mg/kg body weight per day. Fluoride administration led to a partial prevention of the bone loss induced by OVX as shown by histologic analysis of tibial metaphysis and by evaluation of femoral calcium content. These beneficial effects of fluoride were more striking at early time points (1 and 3 months postovariectomy) than after 6 months of treatment. The increase in trabecular bone volume in OVX rats treated with fluoride was associated with a rise in the osteoblast surface, which was increased by 60, 72, and 235% at 1, 3, and 6 months postovariectomy compared to untreated OVX rats. In OVX rats and in sham-operated rats plasma osteocalcin was increased in correlation with the osteoblast surface. However, these two parameters were not correlated in OVX rats treated with fluoride. The heat-labile bone-specific alkaline phosphatase in plasma was decreased in OVX rats treated with fluoride compared to OVX rats, suggesting that both the number and the activity of osteoblasts were affected by NaF treatment. To examine the effect of fluoride on the osteocalcin production and the proliferative capacity of bone cells, osteoblastic cells were isolated by collagenase digestion from the bone surface of tibia in treated and untreated OVX rats.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Effect of fluoride on bone and bone cells in ovariectomized rats. 144 10

Osteoblasts and odontoblasts are both derived from the same mesenchymal cell line. Our aim was to investigate whether the processes of bone destruction and dentinal caries are biologically similar. The working hypothesis was that after the initiation of caries in the enamel, its rate of progression in the dentine is regulated by cell-mediated factors. Experimental caries was induced in the rat with a high sucrose diet combined with Streptococcus sobrinus infection. Both destruction of dentine and its apposition in the pulp under the carious lesions were measured after vital staining with tetracycline. Caries progression and dentine apposition were higher in developing teeth prior to apex "closure" than in adult, fully-formed teeth. Rats placed on a cariogenic diet during tooth development had an increased rate of caries progression. Fluoride administration via the drinking water was associated with decreased dentine apposition and little progression of dentine caries during the developmental stages. Dentine apposition was enhanced in adult rats placed on fluoride administration, while caries progression was reduced, whereas in animals subjected to metabolic acidosis dentine caries progression was enhanced, with reduced dentine apposition. In contrast, alkalotic animals had less dentinal lesions and smaller ones than the controls. Three theories are advanced to explain the observed changes: (i) They may be associated with changes in alkaline phosphatase activity in the pulpo-dentinal complex, (ii) they may be mediated by ionic changes in the dentinal fluid, or (iii) they may reflect the liberation of growth factors from dentinal matrix.
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PMID:Odontoblast-mediated regulation of the progression of dentinal caries. 150 87

The biotransformation of flecainide to serum fluoride after the oral administration of 100 mg to six healthy subjects was studied. Fluoride, flecainide acetate, calcium and alkaline phosphatase serum levels were determined at 0, 3, 4.5 and 6 hours after administration. Higher mean serum concentrations for fluoride and alkaline phosphatase (P less than 0.01, P less than 0.005) and lower mean calcium levels (P less than 0.05) were reached at 4.5 hours. The flecainide acetate serum levels ranged from 108 to 261 ng/ml. The results were analyzed for statistical significance by single factor analysis of variance with repeated measures. The Spearman rank correlation coefficient between flecainide acetate and fluoride serum increases was calculated. Our results would suggest that fluorine-containing flecainide could be biotransformed to yield some ionic fluoride which contribute to the daily fluoride intake.
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PMID:Relationship between serum concentrations of flecainide and fluoride in humans. 175 12

The fluorine introduced analog of 1,25-dihydroxyvitamin D3 [1,25-(OH)2D3], 26,26,26,27,27,27-hexafluoro-1,25-dihydroxyvitamin D3 [26,27-F6-1,25-(OH)2D3] is 5-10 times more potent than 1,25-(OH)2D3 in vitamin D-deficient rats and chicks. In this study we established cultures of human bone cells in order to elucidate the mechanisms responsible for the higher activity of this compound. The effects of 26,27-F6-1,25-(OH)2D3 and 26,26,26,27,27,27-hexafluoro-1,23(S),25-trihydroxyvitamin D3[26,27-F6-1,23(S),25-(OH)3D3], the postulated main metabolite of 26,27-F6-1,25-(OH)2D3, were assessed by the response of alkaline phosphatase (ALP) activity. 26,27-F6-1,25-(OH)2D3 increased ALP activity in a dose-related fashion, from a concentration of 10(-11) M and caused a 3-fold elevation at a concentration of 10(-9) M. To achieve the same stimulating effect on ALP activity, the required dose of 26,27-F6-1,25-(OH)2D3 was 100 times less than that of 1,25-(OH)2D3. Analysis of the receptors of these cells revealed that they have specific receptors for 1,25-(OH)2D3, which have a dissociation constant of 0.9 x 10(-10) M. The competitive binding assays of 26,27-F6-1,25-(OH)2D3 on these receptors showed that binding ability of 26,27-F6-1,25-(OH)2D3 is almost the same as that of 1,25-(OH)2D3. Therefore, receptor binding affinity does not account for the higher potency of 26,27-F6-1,25-(OH)2D3. The trihydroxylated compound, 26,27-F6-1,23(S),25-(OH)3D3 revealed almost the same stimulatory activity on ALP activity in these cells. The most likely explanation for the higher activity of 26,27-F6-1,25-(OH)2D3 than 1,25-(OH)2D3 is that 26,27-F6-1,25-(OH)2D3 is metabolized to 26,27-F6-1,23(S),25-(OH)3D3, which has almost the same activity as 26,27-F6-1,25-(OH)2D3 in target tissues, whereas 1,25-(OH)2D3 is degraded to less active metabolites such as 1,24,25-(OH)3D3.
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PMID:Effect of a highly potent fluoro analog of 1,25-dihydroxyvitamin D3 on human bone-derived cells. 184 18

1. To determine the relationships between parathyroid hormone activity and long-term sodium fluoride therapy in osteoporosis, cytochemical bioassays (for biologically active parathyroid hormone) were performed in 22 osteoporotic control patients and in 18 patients after 15 +/- 10 months of treatment (60 mg of sodium fluoride daily). Ten patients were studied longitudinally by repeated metabolic balances and were therefore common to both groups. All patients were receiving mineral supplements. 2. Cross-sectional data showed a fourfold mean increase in biologically active parathyroid hormone on fluoride treatment (P less than 0.005) together with a 51% increase in serum alkaline phosphatase (P less than 0.005). Longitudinal data showed, in addition, a significant increase in the calcium balance of 2.4 +/- 1.2 (SEM) mmol daily (P less than 0.05) and the development of a positive phosphorus balance (P less than 0.02). 3. Fluoride-treated patients were then analysed in two groups according to the level of biologically active parathyroid hormone. Thirty-two per cent of values were above the upper limit of normal (18 pg/ml). The mean serum alkaline phosphatase level in this group showed no elevation above that of the control patients, the overall rise being accounted for entirely by patients with normal levels of biologically active parathyroid hormone. High levels of biologically active parathyroid hormone were also associated with relative hypophosphataemia (P less than 0.01), relative hypercalciuria (P less than 0.05) and an increased urine/faecal calcium ratio (P less than 0.025). 4. Results show that long-term fluoride and calcium therapy increase biologically active parathyroid hormone in osteoporosis and that excessive parathyroid hormone activity may account for certain features of the refractory state.
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PMID:Fluoride therapy and parathyroid hormone activity in osteoporosis. 216 71


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