Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:3.1.3.1 (alkaline phosphatase)
 47,916 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The activity of alkaline phosphatase isoenzymes from liver, bone and small intestine is differently influenced by Mg2+. The stimulation of isoenzymes from liver and bone is higher by Mg2+ ions than in the case of isoenzymes from small intestine. An obligatory preincubation of the serum sample in a buffer-Mg2+ mixture is necessary to avoid difficulties which may arise in the kinetic determination of alkaline phosphatase activity under extreme conditions, i.e. low Mg2+ concentration in serum, the necessity of dilution of the sample or the high isoenzyme content from liver or bone in the serum.
 ...
PMID:Influence of Mg2+ ions on the activity measurement of isoenzymes of alkaline phosphatase. 51 Feb 76

1-Pyrrolidinecarbothioic acid (2-pyridylmethylene) hydrazide chelates Zn2+ but not Mg2+. This compound is about twice as effective as EDTA for inhibiting alkaline phosphatase from calf mucosa, and approx. 1000-fold more effective than EDTA for inhibiting acid phosphatase from wheat germ. The compound did not inhibit pyridoxine kinase activity in human leucocytes at the highest concentration tested (33 micron). Therefore it may be a useful tool for either examining or eliminating the effects of phosphatases in complex enzyme systems.
 ...
PMID:Simplified preparation of a phosphatase inhibitor and further studies of its action. 65 57

The relationship between the structure and function of alkaline phosphatase (orthoposphoric monoester phosphohydrolase (alkaline optimum), EC 3.1.3.1) isoenzymes is under investigation in a number of laboratories. The present study deals with the effects of glycosidase digestion on the alkaline phosphatase isoenzymes. Changes in physicochemcial properties, activity, affinity for various lectins and blood group antisera, carbohydrate composition and biological half-life were investigated. The desialylated hepatic enzyme was shown to be more heat labile and more sensitive to protease digestion in the presence of 0.5% sodium dodecyl sulfate than native hepatic enzyme. Helix contents of the native and desialated hepatic enzyme were calculated to be 39.0 and 30.8%, respectively, and apparent molecular weights 175,000 and 167,000, respectively. Intestinal enzyme preparations treated with alpha-mannosidase, exo-N-acetyl-Dglucosaminidase and endo-N-acetyl-D-glucosaminidase-D displayed a decrease in enzyme activity. Among these, the alpha-mannosidase-treated enzyme activity was the most clearly reduction. The maximum activity of the alpha-mannosidase-treated intestinal enzyme was observed to change from 40 mM Mg2+ to 5--10 mM Mg2+.
 ...
PMID:The function of carbohydrate moiety and alteration of carbohydrate composition in human alkaline phosphatase isoenzymes. 65 34

The membrane-associated alkaline phosphatase (orthophosphoric-monoester phosphohydrolase (alkaline optimum), EC 3.1.3.1) from Bacillus licheniformis MC14, a facultative thermophile, was purified to homogeneity in buffer containing 0.2 M Mg2+. The alkaline phosphatase purified in this manner is insoluble upon removal of the magnesium by dialysis. This insoluble alkaline phosphatase has been characterized and compared to the previously purified heat-solubilized enzyme (Hulett-Cowling, F.M. and Campbell, L.L. (1971) Biochemistry 10, 1364--1371).
 ...
PMID:Alkaline phosphatase from Bacillus licheniformis. Solubility dependent on magnesium, purification and characterization. 71 47

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.
 ...
PMID:The effect of Mg(II) on the spectral properties of Co(II) alkaline phosphatase. 78 21

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.
 ...
PMID:Influence of complexing agents on stability and activity. 81 4

1. An alkaline phosphatase was partially purified from extracts of Halobacterium cutirubrum. 2. The enzyme has a mol.wt. of 15 500 and is therefore less than one-quarter of the size of other known bacterial alkaline phosphatases. 3. It is stimulated up to ten-fold by Mn2+, but not by Ca2+ or Mg2+. 4. The activities with and without Mn2+ cannot be separated by gel filtration and have similar restricted substrate specificities. 5. The only substrates for the enzyme that have so far been found are p-nitrophenyl phosphate, 5'-dATP, 5'-dTMP and 5'-dTTP.
 ...
PMID:Isolation and properties of a small manganese-ion-stimulated bacterial alkaline phosphatase. 82 41

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.
 ...
PMID:Effect of incubation with Mg2+ on the measurement of alkaline phosphatase activity. 90 17

A study was conducted to determine the feasibility of using the qualitative screening method specifying phenolphthalein monophosphate for differentiating reactivated and residual alkaline phosphatase activity. The relative increase in activity of the enzyme in the presence of MgCl2 serves to distinguish reactivated and residual alkaline phosphatase activity. Ten samples each of pasteurized (172 degrees F for 24 sec), sterilized (about 300 degrees F for a minimum of 2 sec) half-and-half and heavy cream were analyzed. Most samples yielded negative results initially but demonstrated activity after incubation 1 hr at 34 degrees C. The average values in terms of + marks, for the half and half and heavy cream in samples without MgCl2 were less than 1 and 2.4, respectively; for samples treated with MgCl2, the values were 2.18 and 4.6, respectively, indicating reactivated phosphatase activity. In samples containing various levels of raw milk, the activity observed in the diluted, Mg2+-containing samples was less than in the undiluted samples containing no Mg, indicating residual phosphatase activity.
 ...
PMID:Rapid determination of alkaline phosphatase reactivation. 92 45

Certain factors were found to prevent quantitative recovery of soluble alkaline phosphatase from homogenates of chick duodenal mucosa during treatment with n-butanol. Divalent cations such as calcium, manganese and lead interfered when present at 0.1-0.2 mM. Magnesium and zinc were found to reduce enyme recovery when present at 1.0 mM during extraction. These metals had little effect on enzyme activity per se, whether added to the homogenates or enzyme extracts before dilution for assay. However, lead acetate may have a protective or activating effect on phosphatase, at 0.1-10 mM. Other factors affecting the recovery of enzyme activity after butanol solubilization are the state of dilution and pH of the homogenate and individual animal variation.
 ...
PMID:Interference by divalent metals in the preparation of soluble intestinal alkaline phosphatase with n-butanal. 95 79


<< Previous 1 2 3 4 5 6 7 8 9 10 Next >>