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)

Alkaline phosphomonoesterase (EC 3.1.3.1) activity from Blastocladiella emersonii, while displaying typically broad substrate specificity for phosphorylated organic compounds, exhibited nearly complete substrate preference for N-acetylglucosamine-6-phosphate over N-acetylglucosamine-1-phosphate. Enzyme in zoospore extracts was purified 43-fold by differential centrifugation followed by gel filtration (Sephadex G-200) and then by ion-exchange chromatography (diethylaminoethyl-cellulose). The partially purified enzyme displayed an apparent molecular weight (Sephadex G-200) of approximately 170,000. The activity of partially purified enzyme exhibited a pH optimum of pH 8.5, did not require a metal divalent cation, but was inhibitable by ethylenediaminetetraacetic acid. During the life cycle of the organism, the specific activity of the phosphatase decreased slightly during germination and early exponential growth but then increased about 4.5-fold during sporulation. B. emersonii alkaline phosphatase does not appear to be a repressible enzyme.
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PMID:Alkaline phosphatase of Blastocladiella emersonii: partial purification and characterization. 1 78

The effects of a highly acidic environment on the cell-associated alkaline phosphatase activities of a smooth and a rough strain of Escherichia coli O8 have been examined. The observation that cell-associated enzyme is denatured to a lesser degree than purified enzyme suggests that the association of the enzyme with the cell envelope affords it some degree of protection from potentially disruptive agents in the environment. The degree of protection afforded the enzyme from pH denaturation appears to be dependent upon the presence of a complete lipopolysaccharide in the outer membrane of these strains. An abbreviation of the chemical structure of this cell envelope component produces a change in the outer membrane, resulting in increased susceptibility of the cells to a battery of antibiotics and to lysozyme and in a small, but significant, change in the sensitivity of the cell envelope-associated alkaline phosphatase to the denaturing effect of an acidic environment.
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PMID:Cell envelope protection of alkaline phosphatase against acid denaturation in Escherichia coli. 1 81

The aims of this study were to determine the effect of levels of various substances and reaction by-products, which are formed during hydrolysis of nucleic acids, on the derivatization and chromatography of nucleosides; and to investigate the silylation of mono- and dinucleotides. The effect of NaCl, KCl, MgCl2, NH4Cl, and (NH4)2SO4 on silylation and chromatography of nucleosides was studies at various molar excesses of salt. The response values for all nucleosides were studied at various molar excesses of salt. The response values for all nucleosides were significantly affected at molar excess salt present values (MSP) between 1 and 10 for KCl, NaCl, NH4Cl, (NH4)2SO4 and between 0.1 and 1 for MgCl2. It was noted that thymidine was more sensitive than other nucleosides if silylated in presence of these salts. Two chromatographic peaks at retention temperatures (RT) 240 and 251 were obtained for cytidine at MSP values of 10(-3) for NaCl, KCl, and MgCl2, and 10(-4) for NH4Cl and (NH4)2SO4. In a mixture of nucleosides the RT = 251 peak was used for quantitative analysis of cytidine as the RT = 240 peak elutes with guanosine. Thus, these salts have a significant effect on the gas-liquid chromatography of trimethylsilyl (TMS) cytidine in a mixture of nucleosides, especially the RT = 241 peak. The effect of salts on derivatization can be explained in part as follows: (a) reduced derivatization of nucleosides due to a decreased solubility in the solvent system; (b) formation of TMS anion derivatives, e.g. TMS-SO4, TMS-PO4, with a reduced molar excess of BSTFA; (c) metal chelation by Mg ions or other divalent cations with nucleosides or BSTFA; and/or (d) an increased breakdown of TMS derivatives in presence of salt in the sample or on the top 3 in. of the column packing. Also, experiments were made on the effect of other substances such as Tris, phosphate, alkaline phosphatase, and KCl on completeness of silylation. The individual impurities showed no significant effect on the relative weight response (RWR) values of nucleosides; however, when a mixture was used, significantly lower RWR values were observed for all nucleosides except thymidine when using 1000 molar excess of BSTFA greater than 1000 should be used for silylation and chromatography of nucleosides in an RNA hydrolysate. As reported earlier the best derivatization of nucleosides was achieved using closed tube silylation at 150 degrees for 15 min with 225 molar excess BSTFA and chromatography on 4% OV-11 on Supelcoport. In general, the presence of salts and other substances can be significant in quantitative work, thus it is suggested that they be removed using chromatographic cleanup methods. The stability of nucleosides as a function of concentration of HCl, at room temperature was studied and very low RWR values for nucleosides were obtained when stored for 48 h in greater than 0.001 N HCl. Trimethylsilylation of various nucleotides and dinucleotides were made at 15 min as a function of temperature, and at 150 degrees at different times...
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PMID:Derivatization and chromatography of nucleosides and nucleotides. 1 23

Ribonuclease activity has been extracted from adult guinea-pig epidermis by sequential homogenization in dilute sodium acetate and sulfuric acid. The extracts were subjected to ammonium sulfate fractionation and to affinity and ion exchange chromatography. Three ribonucleases (I, II, III) were separated from the sodium acetate extract and 6(A, B1, B2, B3, C, D) were isolated from the sulfuric acid extract. The degree of purification varies from 65-fold to 8,700-fold and the apparent molecular weights of the active forms of 8 of the 9 ribonucleases range from 10,000 to 36,500. No phosphodiesterase activity is present in any of the 9 fractions, but there is alkaline phosphatase activity in one (I) and deoxyribonuclease activity in a second (B3). Two of the ribonucleases have acid pH optima (a1, B3), while the others are most active between PHs 6.8 and 7.8. The activity of 4 of the fractions is sensitive to added EDTA (III, A, B2, B3,), but no stimulatory metal ions were found. Low concentrations of the polyamine spermidine enhanced the activity of 3-fractions (III, C, D). Yeast ribonucleic acid is degraded exonucleolytically by 2 fractions (I, A) and endonucleolytically by the remaining 7. In experiments with homopolyribonucleotide substrates, poly U was generally the preferred substrate. Substantial hydrolysis of poly A occurred with 2 fractions (A, B3) and slight hydrolysis of poly G with 2 other fractions (B2, C).
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PMID:Epidermal nucleases. II. The multiplicity of ribonucleases in guinea-pig epidermis. 1 63

The interaction of human organ alkaline phosphatases (orthophosphoric-monoester phosphohydrolases (alkaline optimum), EC 3.1.3.1) with sugars was studied. Hexosamines, N-acetylneuraminic acid (NANA or sialic acid), N-acetylmuramic acid and N-acetylglycolylneuraminic acid inhibited human organ alkaline phosphatase activities. Of these, sialic acid was the most effective inhibitor. The pH profiles for the enzymes in the absence and presence of sialic acid were similar. The sialic acid - enzyme complex was more heat stable than the free enzyme between 20 and 45 degrees C. Lineweaver-Burk plots of 1/v versus 1/S at various concentrations of sialic acid showed intersecting straight lines indicating that the mechanism of inhibition was a mixed type. The Ki value obtained from the plots of 1/v versus the square of sialic acid concentration was 0.07 mM for the hepatic, sialidase-treated hepatic, and intestinal alkaline phosphatases. The respective Hill coefficients varied somewhat with the alkaline phosphatase isoenzyme. Hyperbolic curves were obtained when the percentage of remaining activity was plotted against the substrate concentration at different concentrations of sialic acid. The Hill coefficient was lowered in the presence of sialic acid. The sialidase-treated hepatic enzymes used gave the most effective conversion. Partial denaturation of the enzyme with urea, or pronase digestion had a little if any effect on the sialic acid inhibition with constant time.
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PMID:Inhibition of alkaline phosphatase by sialic acid. 1 56

Gamma-Glutamyltransferase (GT) and isoenzymes of alkaline phosphatase (ALP) and lactate dehydrogenase (LDH) have been studied in 282 cases with increased S-ALP and in 18 chronic alcoholics with normal routine liver tests. There was a high degree of correlation between S-GT and the bile (alpha 1) and liver (alpha 2) fractions of S-ALP. Fractionation of alkaline phosphatases sometimes yielded clinical information, which could not be obtained by determinations of S-ALP and S-GT only. The presence of alpha 1-ALP and increased S-GT appeared to be more sensitive indicators of ethanol-induced liver involvement than other liver tests, including LDH-5/LDH-4 ratios.
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PMID:Studies on alkaline phosphatase isoenzymes. Relation to gamma-glutamyltransferase and lactate dehydrogenase isoenzymes. 1 7

Plasma membranes were isolated from the livers of control and Streptococcus pneumoniae-infected rats. This work, therefore, represents the first isolation of plasma membranes from infected actron microscopy and by the use of enzyme markers for microsomes (glucose-6-phosphatase), mitochondria (glutamate and malate dehydrogenases), and lysosomes (acid phosphatase). Plasma membranes from infected cells banded at the same sucrose density as plasma membranes from uninfected cells. Moreover, equivalent amounts of plasma membranes could be isolated from control and infected rat livers. There were, however, significant alterations in the enzyme complement of the plasma membrane after infection. 5'-Nucleotidase activity was significantly decreased, whereas alkaline phosphatase activity was significantly increased. Kinetic analysis demonstrated that only the Vmax and not the Km of these two enzymes was changed, suggesting that the altered affinity of the enzymes for substrate was not the mechanism responsible for the observed alterations. No change in the mitochondrial enzyme markers was observed after infection, but the specific activity of microsomal glucose-6-phosphatase decreased significantly. Possible explanations for the observed alterations are discussed.
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PMID:Isolation and partial characterization of plasma membranes from the livers of control and Streptococcus pneumoniae-infected rats. 1 27

A repressible alkaline phosphatase has been isolated from the extreme bacterial thermophile. Thermus aquaticus, and has been purified to homogeneity as judged by disc acrylamide electrophoresis and sodium dodecyl sulfate electrophoresis. Upon investigation, the purified enzyme was shown to hydrolyze certain phosphodiesters in addition to a wide variety of phosphomonoesters. The diesters included bis-p-nitro-phenyl phosphate and thymidine 3'-monophospho-p-nitro-phenyl ester. The temperature optimum for the diesterase activity was 80--85 degrees at pH 7.2. Orthophosphate competitively inhibited both activities. Nucleotides such as AMP, ADP, and ATP also inhibited both esterase activities as did alpha-D-glucose 1-phosphate and alpha-sodium glycerol phosphate. The isoelectric point of the enzyme was determined to be 8.4.
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PMID:Repressible alkaline phosphatase from Thermus aquaticus: associated phosphodiesterase activity. 1

The binding of Ca2+ to a salivary phosphoprotein, protein C, was studied by equilibrium dialysis. In 5mM-Tris/HCl buffer, pH 7.5, protein C bound 190 nmol of Ca2+/mg of protein. The apparent dissociation constant, K, was determined to be 1.9 x 10(-4)M and the binding of Ca2+ to the protein was non-co-operative. The binding of Ca2+ to protein C apparently depends on groups which ionize above pH 5.0. Ca2+ binding decreased with increased concentration of the dialysis buffer and on addition of SrCL2, MgCl2 and MnCl2 to the dialysis buffer. Digestion of protein C with trypsin or collagenase or heating of the protein to 60 degrees or 100 degrees C had little or no effect on the Ca2+ binding. Digestion of protein C with alkaline phosphatase caused a decrease in the amount of protein-bound Ca2+. This was also found for another salivary phosphoprotein, protein A. In the absence of Ca2+ the S020,w for protein C was 1.29 S and in the presence of Ca2+ it was 1.46S. Ca2+ may cause a conformational change in the protein or an aggregation of the protein molecules. No conformational changes of protein C in the presence of Ca2+ could be detected by circular dichroism or nuclear magnetic resonance.
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PMID:The binding of calcium to a salivary phosphoprotein, protein C, and comparison with calcium binding to protein A, a related salivary phosphoprotein. 1 96

Two patients with liver disease due to polyarteritis nodosa are described. They presented in a similar manner, with a swinging fever, a polymorphonuclear leucocytosis and high alkaline phosphatase levels, but the natural history of the illness was different, with revocery in one and death in the other.
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PMID:Polyarteritis nodosa of the liver: a report of two cases. 1 54


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