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)

Over 24-h culture with hydrocortisone (400 nM), activity of brush-border alkaline phosphatase, alpha-glucosidase, and leucyl-2-naphthylamidase and cytoplasmic-mitochondrial malate dehydrogenase increased (P less than 0.05) by 80-133% compared with controls. Uptake of 3-O-methyl-D-[14C]glucose after 24-h culture was increased (P less than 0.05) by 30% compared with cultures without hydrocortisone. Labeling of protein with L-[14C]tyrosine and glycoprotein with D-[3H]glucosamine increased (P less than 0.05) by 40 and 88%, respectively, with hydrocortisone. The effects of hydrocortisone were dose dependent at normal serum concentrations (100-600 nM) and not further stimulated by larger concentrations. Cytoplasmic lactate dehydrogenase and lysosomal hexosaminidase activity, specific radioactivity of soluble precursor pools for protein and glycoprotein labeling, incorporation of [3H]thymidine into DNA, and morphology were unaffected by hydrocortisone. Inhibitors of glucocorticoid receptor binding (progesterone), mRNA transcription (alpha-amanitin), and protein synthesis (cycloheximide) prevented the effects of hydrocortisone. We suggest that hydrocortisone maintains the digestive, absorptive, and cellular function of cultured human jejunum. These protective effects were associated with increased protein synthesis and glycosylation and dependent on a classical steroid-hormone mechanism.
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PMID:Protection of epithelial function in human jejunum cultured with hydrocortisone. 634 19

Placental alkaline phosphatase activity was induced in choriocarcinoma cells by sodium butyrate. Butyrate stimulated de novo synthesis of the enzyme and the increase in phosphatase activity could be completely accounted for by the increase in phosphatase protein: the increases in placental alkaline phosphatase immunoactivity and placental alkaline phosphatase biosynthesis as measured by incorporation of the radioactive precursors, L-[35S]methionine, [3H]mannose, and [3H] glucosamine were similar to the increase in phosphatase activity. Sodium butyrate increased the rates of placental alkaline phosphatase biosynthesis but had no effect on the rate of placental alkaline phosphatase degradation or processing. Both control and butyrate-induced cells contained polypeptides of 61,500 and 64,500 apparent molecular weights that were identified as the precursor and fully processed forms of the placental alkaline phosphatase monomer, respectively. Further, processing of the 61,500-dalton polypeptide to the 64,500-dalton polypeptide involved the incorporation of additional glucosamine and N-acetylneuraminic acid moieties. Gel electrophoresis of anti-placental alkaline phosphatase-precipitable polypeptides from an in vitro protein-synthesizing system directed by RNA isolated from control or butyrate-induced cells demonstrated that sodium butyrate induced the synthesis of placental alkaline phosphatase mRNA. Our data indicate that sodium butyrate induces the specific transcription of the placental alkaline phosphatase gene.
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PMID:Induction of placental alkaline phosphatase biosynthesis by sodium butyrate. 669 79

Polypeptides of 61,500 and 64,500 apparent molecular weights were the precursor and fully processed forms of placental alkaline phosphatase monomer synthesized by choriocarcinoma cells in vivo. [3H] Mannose was incorporated into both polypeptides whereas [3H] glucosamine was incorporated mainly into the 64,500-dalton polypeptide, suggesting processing by the addition of glucosamine moieties. In the absence of microsomal membranes, choriocarcinoma mRNA directed the cell-free synthesis of the preprotein form of alkaline phosphatase monomer of apparent Mr = 60,000. The unglycosylated monomer had an apparent Mr = 58,000. In the presence of microsomal membranes, the 60,000-dalton polypeptide was processed to a polypeptide of apparent Mr = 61,500, comigrating with the precursor form of alkaline phosphatase monomer.
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PMID:Biosynthesis and processing of placental alkaline phosphatase. 683 75

We have isolated from monkey (Macaca radiata) brain lysosomal fraction by phosphomannan-Sepharose chromatography a protein that binds four different lysosomal enzymes, beta-hexosaminidase, beta-glucuronidase, alpha-L-fucosidase and arylsulfatase. The isolated protein which appeared in an aggregated homogeneous form on gel electrophoresis under non-denaturing conditions at both pH 8.3 and pH 5.0 was found to be heterogeneous on SDS-gel electrophoresis with molecular weights less than 67,000. Binding was partly abolished by periodate treatment or by alkaline phosphatase treatment of the lysosomal enzymes. Binding was completely abolished by pronase digestion of the binding protein. Of the different sugars tested for inhibition of binding, mannose-6-phosphate was most effective followed by mannose and N-acetyl glucosamine while glucose and fucose were ineffective.
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PMID:A binding protein for lysosomal enzymes isolated from brain by phosphomannan-sepharose chromatography. 684 56

The effect of thyroxine on biosynthesis of microvillus membrane glycoproteins has been investigated in organ culture of 18-day-old chick embryonic duodenum. Explants incorporate [3H]leucine and [3H]glucosamine continuously, and overall incorporation is enhanced by 10 nM thyroxine during 48 h of labeling; this increase in radioactivity is associated with vesicles released from the microvilli. Light microscope autoradiography, pulse labeling of brush border fragments, and pulse chase experiments reveal that [3H]glucosamine is incorporated into brush border at an increasing rate during culture, and that newly synthesized glycoproteins are discharged into the medium along with brush border enzymes (alkaline phosphatase and maltase). These results suggest that thyroxine stimulates biosynthesis of microvillus membrane glycoproteins, in addition to stimulating vesiculation of the membrane. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis of 3H-labeled vesicles and brush border fragments show that [3H]leucine and [3H]glucosamine are incorporated into proteins of high molecular weight. Two protein bands are identified as alkaline phosphatase and maltase. Thyroxine stimulates glycosylation of these enzymes, but does not change protein patterns. Radioactivity assay of alkaline phosphatase- and maltase-active gel slices suggests that thyroxine stimulation of these enzyme activities during culture is not correlated with de novo synthesis of these proteins.
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PMID:Thyroxine-stimulated synthesis of microvillus membrane glycoproteins during culture of chick embryonic duodenum. 708 68

1. Acid phosphatase (AcPase) from potato tubers was purified by tannic acid fractionation, DEAE-cellulose chromatography, filtration on Bio-Gel P-150 and affinity chromatography on Con A-Sepharose. The enzyme was purified 260-fold and was electrophoretically homogeneous; its mol. mass is about 69 000. 2. The carbohydrate component accounts for 16.6% of the total enzyme weight and includes mannose (5.6%), rhamnose (3.4%), glucose (2.5%), galactose (1.5%) and glucosamine (3.6%). In the amino acid composition aspartic acid, glutamic acid, serine and glycine account for 37.7% of total amino acid residues. 3. Optimum pH is at 5.0-5.3. The enzyme activity was reduced by half after 30 min incubation at 60 degrees C, and was fully abolished after 2 h incubation at 70 degrees C. The enzyme is a nonspecific phosphomonoesterase; aromatic phosphomonoesters and inorganic pyrophosphate can serve as substrates. Apparent Km values were 1.25 mM and 40 mM for p-nitrophenylphosphate and inorganic pyrophosphate, respectively. The enzyme is inhibited by MoO42-, Zn2+, Hg2+ and urea. Inhibition caused by urea was reversible at urea concentration below 9 M.
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PMID:Acid phosphatase of potato tubers (Solanum tuberosum L). Purification, properties, sugar and amino acid composition. 715 77

Ligatin, a receptor that recognizes phosphorylated sugars, was isolated from plasma membranes of mouse macrophages, rat ileum, and rat brain. Several acidic hydrolases including N-acetyl beta-D-glucosaminidase (beta-NAG) were solubilized with this receptor. The solubilized beta-NAG bound to ligatin in vitro as demonstrated by affinity chromatography using the immobilized receptor. beta-N-Acetyl D-glucosaminidase-ligatin complexes were dissociated by low concentrations of mannose 6-phosphate (Man6P) and/or glucose 1-phosphate (Glc 1P). The effectiveness of these two phosphomonosaccharides varied depending on the source of the enzyme: ileal beta-NAG-ligatin complexes showed a four-fold preferential dissociation with Man6P; macrophage complexes showed a 160-fold preferential dissociation with Glc 1P. Brain complexes dissociated with nearly equal preference for Man6P and Glc 1P. Heterologous complexes displayed the specificity characteristic of the source of the enzyme regardless of the source of the ligatin. Treatment of the solubilized hydrolases with endoglucosaminidase H released phosphorous-32 label from these enzymes and prevented binding of beta-NAG to ligatin. However, treatment of the solubilized hydrolases with alkaline phosphatase reduced the binding of beta-NAG to ligatin by no more than 30%. This apparent resistance of beta-NAG to dephosphorylation was consistent with the chromatographic behavior of QAE of 3H-labeled acidic oligosaccharides isolated from the solubilized hydrolases. The oligosaccharides that contain phosphorylated hexose were less acidic than phosphomonoesters and were insensitive to alkaline phosphatase until subjected to acid hydrolysis. These results suggested the presence of a phosphodiester on beta-NAG analogous to the NAC glucosamine 1 P6 mannose present on beta-glucuronidase isolated from mouse lymphoma cells (Tabas I, Kornfield, S: J Biol Chem 255: 6633, 1980).
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PMID:Ligatin binds phosphohexose residues on acidic hydrolases. 729 41

Plasma membranes have been isolated from chicken liver and from Mc-29 virus induced transplantable hepatoma. The purity of membrane preparations has been checked by electron microscopy and by determination of the activity of some enzymes: 5'-nucleotidase, Na+, K+-ATP-ase, Mg2+-ATP-ase, alkaline beta-glycerophosphatase and glucose-6-phosphatase. In hepatoma membranes the activity of 5'-nucleotidase, Na+, K+-ATP-ase and Mg2+-ATP-ase was lower, that of alkaline phosphatase higher, than in liver membrane preparation. The incorporation rate of glucosamine-14C into UDP-N-acetylglucosamine and into plasma membrane glucosamine have been studied as well. The rate of synthesis of UDP-N-acetylglucosamine was faster in liver than in tumor cells. The labeling of hepatoma plasma membranes with glucosamine-14C occurred more slowly than that of liver ones. The rate of transfer of N-acetylglucosamine from UDP-N-acetylglucosamine to membrane-bound glucosamine is lower in hepatoma, than in liver cells.
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PMID:Isolation and partial characterization of plasma membranes from chicken liver and from Mc-29 virus induced transplantable hepatoma. 745 56

Labelling with [3H]glucosamine was used to prepare a transforming growth factor-beta 1 (TGF-beta 1)-sensitive glycosylphosphatidylinositol (GPI) from monolayer cultures of rabbit articular chondrocytes (RAC), which may be involved in control of the cell cycle. The polar headgroup of this glycosylphosphatidylinositol was generated by both phosphatidylinositol-specific phospholipase C (PI-PLC) and pronase E digestion. The molecule emerged in only one peak on a Dowex AG1-X8 chromatogram, eluted at 0.1 N ammonium formate. In contrast, similar experiments performed on cellular extract from cultures previously labelled with [3H]glucosamine displayed four radioactive peaks eluting at 0.1, 0.2, 0.5 and 1 N ammonium formate, respectively. Evidence that the eluting position of these peaks was dependent on the number of phosphate residues present in each fraction was demonstrated by both [32P]phosphorus labelling and change in the position of alkaline phosphatase-induced shift in elution volume. We also demonstrated that the GPI-derived inositolphosphate glycan (IPG) could be hyperphosphorylated into the cell under the action of a kinase whose activity was enhanced by TGF-beta 1 itself. We have also shown that all of these IPG forms could mimic the TGF-beta-induced increase of DNA replication rate of RAC, with a higher activity for peaks III and IV than peaks I and II.
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PMID:Different phosphorylated forms of inositolphosphate glycan could be involved in the transforming growth factor-beta 1 (TGF-beta 1) signalling pathway. 808 80

We describe a quantitative histochemical method for demonstration of five N-acetyl-glucosamine binding lectins in the syncytiotrophoblast of human term placenta. The method employs biotinylated lectins and alkaline phosphatase-conjugated avidin. The alkaline phosphatase activity is detected by using 5-bromo-4-chloro-indoxyl phosphate as the substrate and nitroblue tetrazolium as the capture agent. The effect of 13 fixative solutions on specific lectin binding and nonspecific background staining was quantified by microspectrophotometry. Acid fixatives or fixatives containing mercuric chloride, e.g., Carnoy's and Zenker's fixatives, gave intense specific lectin binding and low background staining. Glutaraldehyde, carbodiimide, and ethanol resulted in low specific lectin binding and a very high background staining that was mainly due to endogenous placental alkaline phosphatase. Lectin binding to N-acetyl-galactosamine, mannose, galactose, and fucose was also significantly higher in sections from tissues fixed in an acid fixative compared with a neutral buffered fixative. Unfixed cryosections revealed a considerably lower degree of specific lectin binding compared with sections from fixed tissues. The activity of endogenous placental alkaline phosphatase was inhibited dose-dependently by mercuric chloride and decreased with L-phenylalanine concentration over the range of 7.8 x 10(-4) M to 5 x 10(-2) M, after which there was no further inhibition. Calf intestinal-type alkaline phosphatase conjugated to avidin was not inhibited by 5 x 10(-2) M L-phenylalanine. Endogenous placental biotin did not contribute significantly to background staining. Despite the high level of placental alkaline phsophatase, the intestinal-type alkaline phosphatase can be used as a marker enzyme in the sensitive ABC technique, provided that the nonspecific background is measured and substracted. Moreover, it is advisable to use an acid- and/or mercuric chloride-containing fixative and to add L-phenylalanine during incubation steps.
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PMID:The impact of fixatives on the binding of lectins to N-acetyl-glucosamine residues of human syncytiotrophoblast: a quantitative histochemical study. 875 58


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