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)

1. Seven subfractions of histone H1 have been isolated and purified from larvae of Chironomus thummi (Diptera). They have been denominated I-1, II-1, II-2, II-3, III-1, III-2, and III-3, according to the order of migration in two steps of preparative electrophoresis. 2. The amino acid compositions are similar to those of other H1 histones. Subfractions I-1 and II-1 were found to contain one methionine and two tyrosine residues, II-2 contained two methionine and three tyrosine residues, and III-1 one methionine and three tyrosine residues. The other subfractions contained one or two methionine and two or three tyrosine residues. For subfractions I-1 and II-1 a chain length of about 252 amino acids was estimated. 3. Peptide pattern analyses after chemical cleavage at the methionine and tyrosine residues, and enzymatic cleavage with thrombin and chymotrypsin, respectively, showed that all subfractions have different individual primary structures. A comparison of peptide sizes and of the positions in the peptide patterns of epitopes recognized by monoclonal antibodies was made to check whether some of the subfractions could arise by proteolytic degradation of others. This possibility can be excluded for five of the subfractions and is very improbable for the two others. Treatment of C. thummi H1 with alkaline phosphatase did not change the pattern of subfractions, while the phosphorylated subfraction of histone H2A disappeared after this treatment. Most and very probably all subfractions are thus H1 sequence variants. 4. Inbred strains and individual larvae of C. thummi were found to comprise all seven variants. The H1 heterogeneity can therefore not be due to allelic polymorphism. Salivary gland nuclei were found to contain variant I-1 and at least some of the other variants. 5. H1 from Drosophila melanogaster and from calf thymus were used as reference molecules in all cleavage experiments and yielded the peptide patterns expected from the sequence. The comparison discriminates the group of C. thummi H1 histones clearly from Drosophila and calf thymus H1. Limited trypsin digestion yielded a protected peptide of uniform size in six of the seven variants which was considerably smaller than the protected central domain of calf thymus H1. 6. Two other species of Chironomidae, C. pallidivittatus and Glyptotendipes barbipes were found to contain five and three H1 subfractions, respectively.(ABSTRACT TRUNCATED AT 400 WORDS)
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PMID:Histone H1 heterogeneity in the midge, Chironomus thummi. Structural comparison of the H1 variants in an organism where their intrachromosomal localization is possible. 341 67

Bovine kidney alkaline phosphatase (ALPase) was purified by the sequential application of monoclonal anti-bovine cartilage ALPase affinity, DEAE-cellulose, and Sepharose CL-6B chromatography. Sodium dodecyl sulfate-polyacrylamide-gel electrophoresis showed the presence of a single band corresponding to a molecular weight of 80,000. The N-terminal amino acid sequence of bovine kidney alkaline phosphatase was determined as follows: Leu-Val-Pro-Glu-Lys-Asp-Pro-?-Tyr-Trp-Arg-Asp-Gln-Ala-Gln.
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PMID:Purification and partial amino acid sequencing of bovine kidney alkaline phosphatase. 359 90

Sixty-one patients with liver disorders receiving total parenteral nutrition (TPN) for about 14 postoperative days were divided into three groups based on the parenteral nutritional regimen. The influence of these TPN solutions on the liver function tests and the nutritional assessments, and the availability of the specially formulated amino acid solution were studied. Glucose alone as energy source was infused in Group Ia. The mixture of glucose and fructose was infused in Group Ib. In these patients (Group I), a commercially available amino acid solution was administered simultaneously. A specially formulated amino acid, rich in branched-chain amino acids but poor in aromatic amino acids was infused with the mixture of glucose and fructose in Group II. There was no remarkable elevation of blood glucose and lactate levels in all patients. Blood glucose levels in Group Ib were maintained lower than that in Group Ia. Except for serum alkaline phosphatase, no remarkable abnormality was observed in liver function tests. Body weight changes were less than 5% in each group. Average nitrogen balances were -44.5 mg/kg/day in Group Ia, -5.5 mg/kg/day in Group Ib, -51.5 mg/kg/day in Group II. While the abnormalities in serum amino acid pattern and molar ratio of leucine, isoleucine, and valine to phenylalanine and tyrosine tend to be more enhanced in Group I, these abnormalities returned to near normal in Group II during TPN. By multiple linear regression analyses, 45 kcal/kg/day of energy intake would be required to maintain nitrogen equilibrium and zero body weight change. And when nitrogen intakes were 159 mg/kg/day in Group Ia, 114 mg/kg/day in Group Ib, and 189 mg/kg/day in Group II at 45 kcal/kg/day in energy intake, nitrogen balances were expected to be equivalent. These results suggest that postoperative TPN is good for nutritional support in patients with liver disorders. And also, the combination of glucose and fructose has better effect on nitrogen balance. The postoperative TPN with a specially formulated amino acid solution may be a valuable way of maintaining the nutritional status as well as normal serum amino acid pattern in patients with liver disorders.
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PMID:Postoperative total parenteral nutrition in patients with liver disorders. 392 62

Binding of fibronectins to gangliosides was tested directly using several different in vitro models. Using an enzyme-linked immunoabsorbent assay (ELISA), gangliosides were immobilized on polystyrene tubes and relative binding of fibronectin was estimated by alkaline phosphatase activity of conjugated second antibody. Above a critical ganglioside concentration, the gangliosides bound the fibronectin (GT1b congruent to GD1b congruent to GD1a greater than GM1 much greater than GM2 congruent to GD3 congruent to GM3) in approximately the same order of efficiency as they competed for the cellular sites of fibronectin binding in cell attachment assays (Kleinman et al., Proc natl acad sci US 76 (1979) 3367). Alternatively, these same gangliosides bound to immobilized fibronectin. Rat erythrocytes coated with gangliosides GM1, GD1a or GT1b bound more fibronectin than erythrocytes not supplemented with gangliosides. Using fibronectin in which lysine residues were radioiodinated, an apparent Kd for binding to mixed rat liver gangliosides of 7.8 X 10(-9) M was determined. This value compared favorably with the apparent Kd for attachment of fibronectin to isolated plasma membranes from rat liver of 3.7 X 10(-9) M for fibronectin modified on the tyrosine residue, or 6.4 X 10(-9) M for fibronectin modified on lysine residues. As shown previously by Grinnell & Minter (Biochem biophys acta 550 (1979) 92), fibronectin modified on tyrosine residues did not promote spreading and attachment of CHO cells. It did, however, bind to cells. In contrast, lysine-modified fibronectin both bound to cells and promoted cell attachment. Plasma membranes isolated from hepatic tumors in which the higher gangliosides that bind fibronectin were depleted bound 43-75% less [125I]fibronectin than did plasma membranes from control livers. The findings were consistent with binding of fibronectins to gangliosides, including the same gangliosides depleted from cell surfaces during tumorigenesis in the rat.
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PMID:Fibronectin binding to gangliosides and rat liver plasma membranes. 394 47

Free mRNPs isolated from human term placental tissue were examined for protein kinase and phosphoprotein-phosphatase activities. Free mRNPs incubated with [gamma-32P]ATP in a protein kinase standard buffer show self-phosphorylation in the absence of exogenous substrates. Treatment of phosphorylated products with alkali showed a significant phosphorylation of tyrosine residues within the mRNP-proteins. An alkaline-phosphatase activity was found to be tightly associated with the mRNPs. Both heat stable and heat labile alkaline phosphatase activities were found in the mRNPs. Heat labile alkaline phosphatase is the major isoenzyme form of the mRNPs. The existence of both protein kinase(s) and alkaline phosphatase activities in placental free cytoplasmic mRNPs might suggest that a balance between phosphorylation, specifically on tyrosine residues, and dephosphorylation states of some of the mRNP-proteins is relevant for their physiological functions, and may therefore play a role in the regulation of mRNPs' metabolism and, consequently, in mRNA translation.
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PMID:Alkaline phosphatase and protein kinase(s) activities in free cytoplasmic mRNPs from human term placenta. 394 33

After surgical placement of end-to-side portacaval shunts (PCS), 4 adult mongrel dogs (11.8 to 18.2 kg) were fed purified diets and monitored for approximately 50 weeks for changes in body weight, neurologic status, and an array of clinically important biochemical variables. Two healthy dogs, fed the same diets and maintained in the same environment, were also observed (controls). Body weights were relatively stable over the period of observation. The branched-chain ratio ([valine] + [leucine] + [isoleucine]/[phenylalanine] + [tyrosine]), an index of the degree of change in plasma amino acid concentrations, was significantly lower in dogs with PCS than in controls. Despite this depression in branched-chain ratio, the principals (dogs with PCS) were essentially free of neurologic symptoms. Statistically significant decreases due to portacaval shunting were seen in the serum concentrations of glucose, calcium, urea nitrogen, creatinine, cholesterol, and albumin. Total protein, globulin, and triglyceride concentrations tended to be lower in the serum of principals than in serum of controls, but the differences were not statistically significant. Statistically significant increases due to portacaval shunting were seen in plasma concentrations of total conjugated bile acids and sulfobromophthalein retention. Concentrations of the following compounds tended to be higher in serum of principals than in serum of controls: phosphorus, chloride, uric acid, total bilirubin, lactate dehydrogenase, aspartate transaminase, alanine transaminase, and alkaline phosphatase. Liver biopsy at 7 months after operation showed mild-to-extensive atrophy of hepatocytes, mild-to-extensive fibrosis, and collapsed portal veins in all principals examined.
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PMID:Long-term biochemical and physiologic effects of surgically placed portacaval shunts in dogs. 395 18

Human liver alkaline phosphatase (AP) has been purified to homogeneity. The enzyme has a molecular weight of 150,000 in its native state and consists of two identical subunits of Mr 75,000. After treatment with endoglycosidase F the molecular weight is reduced to 50,000 indicating a high degree of glycosylation. The amino-terminal sequence up to 22 residues was found to be Leu-Val-Pro-Glu-Lys-Glu-Lys-Asp-Pro-Lys-Tyr-(Ala)-Arg-Asp-Gln-Ala-Gln-?- Thr-Leu-Lys-Tyr. The amino-terminal portions of human and bovine liver AP are identical. The amino termini of the human liver and human placental AP isozymes have appreciable homology. Conformationally the amino termini are very similar.
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PMID:Human liver alkaline phosphatase, purification and partial sequencing: homology with the placental isozyme. 395 57

The phosphorylation characteristics of insulin receptor from control and insulin-treated rat H-35 hepatoma cells 32P-labeled to equilibrium have been documented. The 32P-labeled insulin receptor is isolated by immunoprecipitation with patient-derived insulin receptor antibodies in the presence of phosphatase and protease inhibitors to preserve the native phosphorylation and structural characteristics of the receptor. The unstimulated insulin receptor contains predominantly [32P] phosphoserine and trace amounts of [32P]phosphothreonine in its beta subunit. In response to insulin, the insulin receptor beta subunit exhibits marked tyrosine phosphorylation and a 2-fold increase in total [32P]phosphoserine contents. High pressure liquid chromatography of the tryptic hydrolysates of the 32P-labeled receptor beta subunit from quiescent cells results in the resolution of up to 9 fractions containing [32P]phosphoserine. The insulin-stimulated tyrosine phosphorylation is concentrated in two of these receptor phosphopeptide fractions, whereas the increase in [32P]phosphoserine content is scattered in low abundance over all receptor tryptic fractions. Insulin receptors affinity-purified by lectin- and insulin-agarose chromatographies from insulin-treated, 32P-labeled cells exhibit a 22-fold increase in the Vmax of receptor tyrosine kinase activity toward histone when compared to controls. The elevated kinase activity of the insulin receptor derived from insulin-treated cells is not due to the presence of hormone bound to the receptor because the receptor kinase activity is assayed while immobilized on insulin-agarose. Furthermore, the insulin-activated receptor kinase activity is reversed following dephosphorylation of the receptor beta subunit with alkaline phosphatase in vitro. The correlation between the insulin-stimulated site specific tyrosine phosphorylation on receptor beta subunit and the elevation of receptor tyrosine kinase activity strongly suggests that the insulin receptor kinase is activated by hormone-stimulated autophosphorylation on tyrosine residues in intact cells, as previously demonstrated for the purified receptor.
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PMID:Tyrosine phosphorylation of insulin receptor beta subunit activates the receptor tyrosine kinase in intact H-35 hepatoma cells. 395 14

Bovine liver alkaline phosphatase has been purified to homogeneity by procedures that include reverse-phase HPLC. The pure enzyme has an apparent Mr of 160,000 and is composed of what appears to be two identical monomers of Mr 82,000. About 80% of the material yielded the amino-terminal sequence Leu-Val-Pro-Glu-Lys-Glu-Lys-Asp-Pro-?-Tyr-?-Arg-Asp-Gln-Ala-Gln. The minor component was extended at the amino terminus by two residues that have not yet been identified, i.e., ?-?-Leu-Val-Pro-Glu-Lys-Glu-Lys-Asp-Pro-?-Tyr-?-Arg-Asp-Gln-Ala-Gln.
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PMID:Purification and partial sequencing of bovine liver alkaline phosphatase. 403 95

The enzymic properties of alkaline phosphatase (EC 3.1.3.1) from pig kidney brush-border membranes were studied. 1. It hydrolyses ortho- and pyro-phosphate esters, the rate limiting step (V(max.)) being independent of the substrate. It transphosphorylates to Tris at concentrations above 0.1m-Tris. 2. The pH optimum for hydrolysis was between 9.8 and 10. The pK of the enzyme-substrate complex is 8.7 for p-nitrophenyl phosphate and beta-glycerophosphate. Excess of substrate inhibits the enzymic activity with decreasing pH. The pK of the substrate-inhibited enzyme-substrate complex, 8.7, is very similar to that for the enzyme-substrate complex. The pK values of the free enzyme appear to be 8.7 and 7.9. 3. Inactivation studies suggest that there is an essential tyrosine residue at the active centre of the enzyme. 4. The energy of activation (E) and the heat of activation (DeltaH) at pH9.5 showed a transition at 24.8 degrees C that was unaffected by Mg(2+). 5. Kinetic and atomic-absorption analysis indicated the essential role of two Zn(2+) ions/tetrameric enzyme for an ordered association of the monomers. Zn(2+) in excess and other bivalent ions compete for a second site with Mg(2+). Mg(2+) enhances only the rate-limiting step of substrate hydrolysis. 6. Amino acid inhibition studies classified the pig kidney enzyme as an intermediate type of previously described alkaline phosphatases. It has more similarity with the enzyme from liver and bone than with that from placenta.
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PMID:Catalytic properties of alkaline phosphatase from pig kidney. 437 71


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