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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)

Colonic and small intestinal alkaline phosphatase extracts were studied biochemically and electrophoretically to elucidate the source of a reported difference in cellulose acetate electrophoretic mobility. Both preparations were inactivated with 0.5 mmol/L L-phenylalanine but retained full activity in the presence of 1.0 mmol/L tetramisole. Treatment with neuraminidase changed a minor fraction of the small intestinal but the major portion of the colonic alkaline phosphatase to a cathodically migrating form. The most likely explanation for our findings is that the colon and small intestinal alkaline phosphatase are mixtures of the same multiple forms but in different proportions.
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PMID:On the difference between colonic and small intestinal alkaline phosphatase. 404 23

The physical characteristics of nonspecific alkaline phosphatase (ALP) from both mouse primordial germ cells (PGCs) and gonads were compared with corresponding samples from other organs at different developmental stages. Combining a cytochemical approach with polyacrylamide gel electrophoresis and the use of specific inhibitors, as well as neuraminidase treatment, heat sensitivity tests, and molecular-mass criteria, it was found that only one ALP isoenzyme was present in all organs up to day 14 of gestation. Distinct ALP isoenzymes first appeared in the small intestine on day 15 and, thereafter, in all other tissues except the gonads. In these organs, the embryonal ALP isoenzyme seemed to be retained until adulthood. Although the placenta had a different ALP isoenzyme than the embryo at all stages, this isoenzyme was found to be similar to that in the maternal decidual tissues. Therefore, we conclude that the mouse embryo only expresses one type of ALP that can be considered "embryonal", regardless of the organ in which it first appears, and that this ALP is conserved in the gonads.
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PMID:Characterization of alkaline phosphatase from primordial germ cells and ontogenesis of this enzyme in the mouse. 404 84

An isoelectric focusing technique in agarose gel is presented which is suitable for alkaline phosphatases from both serum and tissue sources. An anomaly in the literature about isoelectric focusing of serum alkaline phosphatase from liver origin is discussed and a possible explanation is proposed. The presented technique is used to demonstrate some differences in behaviour of serum liver and bone isoenzymes towards neuraminidase treatment.
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PMID:Isoelectric focusing of alkaline phosphatases in agarose gel. 406 4

The main alkaline phosphatase isoenzymes of human bile have been purified by DEAE-cellulose chromatography. Characteristics of the isoenzymes, such as electrophoretic mobility before and after butanol extraction, Michaelis constant, and change in electrophoretic mobility following exposure to neuraminidase have been studied and compared with isoenzymes from other sources. The results show that the main alkaline phosphatase of bile is derived from the liver. It is present as a protein phosphatidylcholine complex.
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PMID:The nature of the alkaline phosphatases of bile. 411 11

Alkaline phosphatase (EC 3.1.3.1) from pig kidney brush-border membranes was solubilized from membrane precipitates by butan-1-ol at a critical pH of 7.0. The 12000-fold purification procedure included (NH(4))(2)SO(4) precipitation, DEAE-and TEAE-cellulose chromatography, Sephadex G-200 gel filtration and neuraminidase digestion followed by DEAE-cellulose chromatography. The purified protein contained 20% (w/w) carbohydrate and had mol.wt. 150000-156000 as estimated by Sephadex filtration and ultracentrifuge analysis. It was a tetrameric glycoprotein consisting of identical subunits, and it had a molecular activity at 25 degrees C of 2600s(-1) per tetramer. Its concentration in kidney was estimated to be 8.5-8.8mg/kg.
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PMID:Alkaline phosphatase from pig kidney. Method of purification and molecular properties. 445 5

Several alkaline phosphatases (EC 3.1.3.1) could be obtained from pig kidney brush-border membrane on extraction with butan-1-ol. Three of the multiple forms were separated by DEAE-cellulose chromatography and further purified. They form a regular series with different degrees of glycosylation (mainly owing to N-acetylneuraminic acid), of charge, of molecular weight, of stability to temperature, to pH and to urea, of minimal requirement for Mg(2+) and of extractability by butan-1-ol. In contrast, the detectable antigenic sites, the inhibition by amino acids and the pH-dependency of K(m) and V(max.) were identical for these multiple forms. On treatment with neuraminidase, the multiple forms became identical in all their properties. It was therefore concluded that the microheterogeneity of alkaline phosphatase is due to different degrees of glycosylation at polypeptide chains which appear to be otherwise identical.
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PMID:Alkaline phosphatase from pig kidney. Microheterogeneity and the role of neuraminic acid. 445 6

The two main alkaline phosphatase isoenzymes in serum from patients with extrahepatic biliary obstruction have been purified. Properties of these isoenzymes, such as electrophoretic mobility, separation on gel filtration, ultracentrifugation characteristics, Michaelis constants, and sensitivity to neuraminidase have been studied and compared with the isoenzymes of liver and bile. The results show that there is an abnormal isoenzyme in the serum from these patients and that this isoenzyme is similar but not identical with the main bile isoenzyme. It is suggested that it may be associated with a lipoprotein carrier.
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PMID:The nature of the serum alkaline phosphatases in liver diseases. 485 65

Bile duct ligation in the rat leads to a rapid increase in hepatic and serum alkaline phosphatase activity. Within 12 hr after bile duct ligation, hepatic alkaline phosphatase has increased 7-fold and serum alkaline phosphatase activity 2(1/2)-fold. The elevation in the serum activity is completely due to an increase in an isozyme that appears to originate in the liver. This serum isozyme and liver phosphatase, both partially purified by DEAE-cellulose column chromatography, have identical Michaelis constants, pH optima, and rates of heat denaturation. These isozymes migrate identically when subjected to electrophoresis on polyacrylamide gel, and their migration rates are equally slowed after neuraminidase digestion. The data suggest that the rise in hepatic alkaline phosphatase activity is dependent on de novo protein synthesis. Cycloheximide, in a dose that inhibited incorporation of leucine-(14)C into protein by 68%, inhibited the rise in liver phosphatase by 98% and that in serum by 80%. The rise in liver phosphatase activity could not be accounted for by simple retention of alkaline phosphatase that would normally appear in bile. The rise in liver activity after bile duct ligation was 240 times greater than the amount of phosphatase that normally appears in bile over a similar period of time. Cycloheximide had no effect on the bile duct ligation-induced changes in the serum and liver glutamic pyruvic transaminase.
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PMID:Induction of rat liver alkaline phosphatase: the mechanism of the serum elevation in bile duct obstruction. 541 76

Evidence is presented in this paper which supports the hepatogenic theory for the mechanism by which the level of serum alkaline phosphatase is raised in liver disease and provides additional evidence that serum phosphatase is not excreted in the bile. By starch gel and paper electrophoresis the normal serum alkaline phosphatase isoenzyme is shown to be rarely present in hepatic bile. The action of neuraminidase demonstrates that beta-globulin isoenzymes of liver and bone are not identical. From these results a theory which clarifies the rationale of the elevation of alkaline phosphatase in bone and liver disease is postulated. The proposed mechanism may be summarized as follows. The normal serum level is the result of two factors, the rate of release of the enzyme from the tissues, principally liver and bone, and the rate of inactivation of the enzymes in the serum and body protein pool. In osteoblastic bone disease the elevated level is due to the rate of release of the enzyme exceeding the rate of inactivation. The raised level does not indicate an inability of the liver to excrete the enzyme via the biliary tract. In liver disease the increase in serum levels is a result of increased liberation of the enzyme from the sinusoidal surface of the liver cell and of regurgitation of the biliary isoenzyme back into the serum.
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PMID:An interpretation of the elevation of serum alkaline phosphatase in disease. 560 83

1. Two alkaline phosphatase fractions from sheep brain obtained by DEAE-cellulose column chromatography were shown to be associated with different concentrations of NANA (N-acetylneuraminic acid). Enzyme II contains nearly three times as much NANA as does enzyme I. 2. Partial removal of NANA by neuraminidase digestion from these alkaline phosphatase fractions has different effects on their chromatographic properties. Though the enzymic release of NANA has no effect on the elution pattern of enzyme I from a DEAE-cellulose column, such a treatment shifts the elution pattern of enzyme II towards that of enzyme I. 3. However, this change in the elution pattern of enzyme II as a result of the removal of NANA does not produce any change in the kinetics of this fraction, and the differences between enzyme I and enzyme II with respect to their substrate affinities and K(i) for phosphate inhibition are maintained even after the removal of NANA. 4. Results indicate that NANA is not the only factor responsible for the heterogeneity of alkaline phosphatase in sheep brain and enzyme I is not the result of the removal of NANA from enzyme II.
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PMID:Role of neuraminic acid in the heterogeneity of alkaline phosphatase in sheep brain. 564 74


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