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)

Callus calcifying cartilage alkaline phosphatase was resolved by DEAE-cellulose column chromatography into two distinct phsophatase activities. The phosphatase activity which was eluted first from the column, (phosphatase I), was active towards a variety of phosphate esters, sodium pyrophosphatase and several linear polyphosphates, while the second phosphatase activity , (phosphatase II), was active toward simple phosphate esters but not towards sodium pyrophosphate and linear oligo or polyphosphates. All the phosphate esters, sodium pyrophosphate and polyphosphates at higher concentrations were inhibitory for phosphatase I. The modulating effects of magnesium, calcium, zinc and other phosphatase modulators have been investigated. Both phosphatases from callus calcifying cartilage were found to be substrates of neuraminidase with sialic acid as the product. Besides the difference in their specificity, the phosphatases were found to be immunologically different and to have different molecular weights, strong indication that they are different enzymes.
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PMID:Resolution, purification and characterization of the orthophosphate releasing activities from fracture callus calcifying cartilage. 23 99

A mutant strain of Serratia marcescens produces a constitutive enzyme (phosphatase F), which differs from the alkaline phosphatase of Escherichia coli in the following characteristics: one enzyme species with higher mobility on electrophoresis, less heat stability, no rapid reactivation following exposure to high hydrogen ion concentrations, no hybridization with E. coli enzyme in vitro, little activation at increased ionic strength, greater sensitivity to EDTA inhibition, and no cross reaction of rabbit anti-serum with the E. coli enzyme.
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PMID:Some distinctive characteristics of the alkaline phosphatase of Serratia marcescens. 23 23

Improved histochemical techniques for the demonstration of NADP+-specific isocitrate dehydrogenase and malate dehydrogenase in tissue sections are described. With these techniques a semipermeable membrane is interposed between the incubating solutions and the tissue sections preventing diffusion of enzymes into the medium during incubation. In the histochemical system the NADP+-dependent enzymes catalyze the electron transfer from threo-Ds-isocitrate or L-malate into NADP+. Phenazine methosulphate and menadione serve as intermediate electron acceptors between reduced coenzyme and nitro-BT. Sodium-azide and amytal are incorporated into the incubating-medium to block electron transfer to the cytochromes. For demonstrating enzyme activities in sections containing non-specific alkaline phosphatase, a phosphatase inhibitor is added into the incubation media. Problems involved in the histochemical demonstration of both enzymes are discussed.
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PMID:Semipermeable membranes for improving the histochemical demonstration of enzyme activities in tissue sections. V. Isocitrate: NADP+ oxidoreductase (decarboxylating) and malate: NADP+ oxidoreductase (decarboxylating). 23 22

Kidney alkaline phosphatase is an enzyme which requires two types of metals for maximal activity: zinc, which is essential, and magnesium, which is stimulatory. The main features of the Mg2+ stimulation have been analyzed. The stimulation is pH-dependent and is observed mainly between pH 7.5 and 10.5. Mg2+ binding to native alkaline phosphatase is characterized by a dissociation constant of 50 muM at pH 8.5,25 degrees. Binding of Zn2+ is an athermic process. Both the rate constants of association, ka, and of dissociation, kd, have low values. Typical values are 7 M(-1) at pH 8.0, 25 degrees, for ka and 4.10(-4) S(-1) at pH 8.0, 25 degrees, for kd. The on and off processes have high activation energies of 29 kcal mol (-1). Mg2+ can be replaced at its specific site by Mn2+, Co2+, Ni2+, and Zn2+. Zinc binding to the Mg2+ site inhibits the native alkaline phosphatase. Mn2+, Co2+, and Ni2+ also bind to the Mg2+ site with a stimulatory effect which is nearly identic-al with that of Mg2+, Mn2+ is the stimulatory cation which binds most tightly to the Mg2+ site; the dissociation constant of the Mn2+ kidney phosphatase complex is 2 muM at pH 8.5. The stoichiometry of Mn2+ binding has been found to be 1 eq of Mn2+ per mol of dimeric kidney phosphatase. The native enzyme displays absolute half-site reactivity for Mn2+ binding. Mg2+ binding site and the substrate binding sites are distinct sites. The Mg2+ stimulation corresponds to an allosteric effect. Mg2+ binding to its specific sites does not affect substrate recognition, it selectively affects Vmax values. Quenching of the phosphoenzyme formed under steady state conditions with [32P]AMP as a substrate as well as stopped flow analysis of the catalyzed hydrolysis of 2,4-dinitrophenyl phosphate or p-nitrophenyl phosphate have shown that the two active sites of the native and of the Mg2+-stimulated enzyme are not equivalent. Stopped flow analysis indicated that one of the two active sites was phosphorylated very rapidly whereas the other one was phosphorylated much more slowly at pH 4.2. Half of the sites were shown to be reactive at pH 8.0. Quenching experiments have shown that only one of the two sites is phosphorylated at any instant; this result was confirmed by the stopped flow observation of a burst of only 1 mol of nitrophenol per mol of dimeric phosphatase in the pre-steady state hydrolysis of p-nitrophenyl phosphate. The half-of-the-sites reactivity observed for the native and for the Mg2+-stimulated enzyme indicates that the same type of complex, the monophosphorylated complex, accumulates under steady state conditions with both types of enzymes. Mg2+ binding to the native enzyme at pH 8.0 increases considerably the dephosphorylation rate of this monophosphorylated intermediate. A possible mechanism of Mg2+ stimulation is discussed.
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PMID:Bovine kidney alkaline phosphatase. Catalytic properties, subunit interactions in the catalytic process, and mechanism of Mg2+ stimulation. 23 94

The tissue content of pyridoxal 5'-phosphate is controlled principally by the protein binding of this coenzyme and its hydrolysis by a cellular phosphatase. The present study identifies this enzyme and its intracellular location in rat liver. Pyridoxal-P is not hydrolyzed by the acid phosphatase of intact lysosomes. At pH 7.4 and 9.0, the subcellular distribution of pyridoxal-P phosphatase activity is similar to the for p-nitrophenyl-P, and the major portion of both activities is found in the plasma membrane fraction. The ratio of specific activities for pyridoxal-P and p-nitrophenyl-P hydrolysis remains relatively constant during the isolation of plasma membranes. These activities also behave concordantly with respect to pH rate profile, pH-Km profile, and response to chelating agents, Zn2+, Mg2+, and inhibitors. Kinetic studies indicate that pyridoxal-P binds to same enzyme sites as beta-glycerophosphate and phosphorylcholine. The data strongly favor alkaline phosphatase as the enzyme which functions in the control of pyridoxal-P and pyridoxamine-P metabolism in rat liver. Alkaline phosphatase was solubilized from isolated plasma membranes. The kinetic properties of the enzyme are not markedly altered by its dissociation from the membrane matrix. However, there are significant differences in its behavior toward Mg2+ which suggest a structural role for Mg2+ in liver alkaline phosphatase.
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PMID:Characterization of the pyridoxal 5'-phosphate and pyridoxamine 5'-phosphate hydrolase activity in rat liver. Identity with alkaline phosphatase. 24 Aug 52

The reovirus oligoadenylates exist in two states within the virion: free and bound to viral proteins. The latter class of oligonucleotides, after digestion with Penicillium (P1) nuclease, yields adenylic acid and an adenosine-containing compound that is positively charged at pH 1.7, 3.5, or 6.5. In a mixture of [35S]methionine- and [3H]adenosine-labeled reovirus disrupted by sodium dodecyl sulfate/urea, approximately 4% of the radioactivity in [35S]methionine-labeled proteins coelutes with [3H]adenosine-labeled material at a net charge of -1.5 when analyzed by ion-exchange chromatography on DEAE-cellulose. This material migrates in sodium dodecyl sulfate/polyacrylamide gels with mu polypeptides and with a small protein, viii. Radioactivity is not released when the complex is boiled in buffer containing sodium dodecyl sulfate and urea or boiled in 80% dimethyl sulfoxide or when viral RNA is extracted with phenol. Digestion with Pronase converts the [3H]adenosine-labeled compound to oligomers of net charge -8 to -12 which contain nuclease P1- and alkaline phosphatase-sensitive adenylic acid residues as well as adenosine in a P1- and phosphatase-resistant linkage. These data indicate that reovirus contains structural proteins that are covalently bound to an oligoadenylate moiety.
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PMID:Polyadenylylation of proteins in reovirions. 29 Sep 87

When Escherichia coli cells were grown in media containing either phosphite or hypophosphite as the sole source of phosphorus, the responded to this situation primarily in the same way as phosphate-limited cultures: The activity of alkaline phosphatase increased drastically, which under natural conditions would enable the cells to compensate for the shortage of phosphate. Subsequent transfers, however, resulted in a quite different response: While the phosphatase activity of phosphate-limited cells stays at a high derepressed level, its increase was followed by a gradual decline in organisms grown on phosphite of hypophosphite. After eight to ten transfers on these P-compounds, phosphatase activity was back to its initial, repressed, low level, indicating that the cells were fully adapted to these substrates. Adaptation to either PO3-3 or PO3-2 was completely abolished if the cells were again grown with PO3-3 as P-source, whereafter the entire process of adaptation had to be repeated. The observed adaptation pattern, reflected by the alterations of phosphatase activity, was qualitatively equal with PO3-3 and PO3-2, but quantitatively different, because the response to hypophosphite gave much higher values than the increase obtained with phosphite. Phosphite-adapted cells are not simultaneously adapted to hypophosphite, but their response to the latter was less intense than observed after direct transfers from PO3-4 to PO3-2. Adaptation to hypophosphite, however, led simultaneously to phosphite adaptation, so that these cells can utilize both P-compounds as a substitute for phosphate.
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PMID:Alterations of alkaline phosphatase activity during adaptation of Escherichia coli to phosphite and hypophosphite. 32 Sep 53

A clinical investigation has been carried out into the effect of small electrical currents on the healing of mandibular fractures. Electrical stimulation of fracture healing was carried out in 40 patients with a direct current of 10 or 20 microamperes delivered through a platinum electrode. An equal number of patients with similar fractures were selected as controls. Rate of repair was assessed by measuring the mobility of the fracture. Serum phosphatase and calcium were regularly measured at intervals in both groups after reduction and suggested that alkaline phosphatase activity increased in the stimulated group. The repair process was enhanced in the electrically stimulated fractures compared to the controls in the first 10-14 days after reduction.
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PMID:Preliminary clinical evaluation of the effect of small electrical currents on the healing of jaw fractures. 34 89

Acid phosphatase activity was detected in Streptococcus mutans strain NCTC 10832, and both acid and alkaline phosphatase in strains 2M2 and K1R. In batch culture, activity was maximal by mid exponential phase for 2M2 and at the end of this phase for NCTC 10832. Alkaline, but not acid, phosphatase activity of 2M2 and K1R increased when the inorganic phosphate in the medium was low; this was considered due, at least partly, to inducible or derepressible enzymes. In continuous culture, acid phosphatase activity of NCTC 10832 varied with the sugar substrate. The activity was increased by cell disruption and the degree of this increase for cells grown on different sugars parallelled the amounts of extracellular, insoluble polysaccharide produced on those sugars. Activity was highest for glucose-grown whole cells and for sucrose-grown disrupted cells.
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PMID:The influence of certain growth conditions on the phosphatase activity of Streptococcus mutans grown in batch and continuous culture. 37 33

An antikidney phosphatase serum was produced. This showed a cross-reaction with liver phosphatase and precipitated the latter enzyme specifically in the double antibody method. An U-[14C] protein hydrolysate was injected intraperitoneally into rats, which had previously undergone bile duct ligation. Liver alkaline phosphatase was partially purified and immunoprecipitated. By determination of phosphatase labelling the extent of de novo synthesis of the phosphatase protein was evaluated. Comparing livers from control and cholestatic rats, it could be shown that 12 h after beginning of cholestasis the de novo synthesis of alkaline phosphatase was increased up to 4-fold and that is remained at a 2-fold increased level for at least 2 days.
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PMID:Evidence for an enhanced de novo synthesis of alkaline phosphatase in cholestatic rat liver using immunotitration and precursor incorporation techniques. 38 11


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