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)

An acidic glycoconjugate containing mannose, galactose and phosphate in approximately equimolar amounts was extracted from Leishmania donovani promastigotes and partially characterized. The glycoconjugate could be metabolically labeled with either [3H]mannose or [3H]galactose and was extractable from a delipidated residue fraction with water/ethanol/diethyl ether/pyridine/concentrated NH4OH (15:15:5:1:0.017) at 25 degrees C. The radioactively labeled glycoconjugate was found to possess the following characteristics: 1) comprised 45-60% of the total [3H]mannose label incorporated into macromolecules; 2) was soluble in alkaline solvents and 0.5% Triton X-100; 3) migrated as a broad band upon electrophoresis on sodium dodecyl sulfate-polyacrylamide gels with an approximate molecular weight of 15,000-30,000; 4) bound to DE52 cellulose and was eluted with a salt gradient of 0-0.1 M NaCl; 5) was insensitive to Pronase, hyaluronidase, chondroitinase, endo-beta-N-acetylglucosaminidase H, and endo-beta-galactosidase; and 6) possessed hydrophobic properties. An unusual feature of the glycoconjugate was its lability to mild acid hydrolysis (0.02 N HCl, 15 min, 60 degrees C). As determined by alkaline phosphatase and glycosidase digestion and paper chromatographic analysis, the major fragment generated by mild acid hydrolysis was found to be a phosphorylated galactosyl-beta-mannose disaccharide. All of these characteristics suggest that the glycoconjugate may be a polysaccharide and, possibly, may be important in parasite-host cell interactions.
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PMID:Expression of an unusual acidic glycoconjugate in Leishmania donovani. 670 85

When cells of the slime mould Dictyostelium discoideum are allowed to starve in the presence of alpha-chymotrypsin, they are blocked in development at the stage where tight aggregates form tips. Analysis of developmentally regulated enzymes has shown that alpha-mannosidase, beta-N-acetylglucosaminidase, threonine deaminase, tyrosine aminotransferase, beta-glucosidase and the carbohydrate-binding protein discoidin are unaffected, but enzymes that show an increase in specific activity during post-aggregative development, namely glycogen phosphorylase, UDP-glucose pyrophosphorylase, UDP-galactose 4-epimerase, UDP-galactose polysaccharide transferase and alkaline phosphatase, did not show the characteristic increase when development was blocked by alpha-chymotrypsin. Recovery of cells from the effects of alpha-chymotrypsin was accompanied by the formation of fruiting bodies and a concomitant increase in the specific activity of UDP-glucose pyrophosphorylase. Uptake or efflux of 45Ca2+ was not altered in the presence of alpha-chymotrypsin. Cells allowed to develop in alpha-chymotrypsin, or treated with the enzyme for 15 min, had a markedly reduced ability to bind cyclic AMP with low affinity; high-affinity binding was unaffected. Pronase had a similar effect on cyclic AMP binding, but trypsin, which does not alter developmental processes, has no effect on cyclic AMP binding to D. discoideum cells.
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PMID:Developmentally regulated enzymes and cyclic AMP-binding sites in Dictyostelium discoideum cells blocked during development by alpha-chymotrypsin. 715 Feb 39

Improved maintenance in vitro of the hematopoietic tissue of the Dublin Bay prawn Nephrops norvegicus (L.) resulted by using 10% (v/v) 2x Leibovitz's medium prepared in seawater (salinity = 25 per thousand), and supplemented with 10% (v/v) heat inactivated fetal bovine serum plus 5% (v/v) Nephrops serum or 5% (v/v) Nephrops muscle extract, and 0.06 g/l of L-proline and 1 g/l of glucose. Pronase at 100 microg/ml improved tissue dissociation and subsequent spreading of hematopoietic cell cultures. The addition of epithelial growth factor (EGF), based fibroblast growth factor (bFGF) or insulin growth factor 1 (IGF-I) did not enhance cell growth. Cell culture contained several types of maturing hemocytes, in the size range of 6-24 microm diameter. Acid phosphatase, alpha-naphthyl butyrate esterase, alpha-naphthyl acetate esterase, naphthyl AS-D chloroacetate esterase activity and phenoloxidase activity was demonstrated, but not so alkaline phosphatase or peroxidase. Small PAS (= Periodic acid Schiff) positive granules, unsaturated lipids and phospholipids were observed. Cultures remained functional for over two weeks. Mitosis was noticed occasionally; however, cell proliferation was not recorded by use of nuclear proliferation markers.
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PMID:Development and characterization of primary cell cultures from the hematopoietic tissues of the Dublin Bay prawn, Nephrops norvegicus. 1154 39

Phage varphiX174 A(*) protein cleaves single-stranded DNA and then binds to the 5'-phosphorylated terminus of the cleaved DNA fragment, forming a covalent protein-DNA complex. The bound A(*) protein can religate the termini to form covalently closed single-stranded circles. To determine the nature of the covalent linkage and the amino acid involved, we used A(*) protein to cleave DNA synthesized in vivo with [alpha-(32)P]dATP to form the A(*)-single-stranded DNA complex. The complex was then digested with DNase I and the (32)P-labeled A(*) protein was isolated by electrophoresis on polyacrylamide gels. The isolated complex was digested with either trypsin or Pronase. Incubation of the tryptic digest with snake venom phosphodiesterase gave (32)P-labeled products that migrated on electrophoresis on cellulose plates to the cathode, indicating covalent linkage of (32)P-labeled dAMP residues to a tryptic peptide. High concentrations of snake venom phosphodiesterase released all of the (32)P label as free dAMP. Formic acid/diphenylamine depurination (Burton reaction) of the [alpha-(32)P]dATP-labeled peptide-oligonucleotide complexes caused a transfer of the labeled phosphate from dAMP to the peptide. The phosphorylated peptides were isolated on cellulose plates and shown to be sensitive to bacterial alkaline phosphatase, indicating that a phosphodiester bond linked the peptides to the dAMP. The phosphorylated product of the Pronase digest was identified as free phosphotyrosine by its mobility in three different chromatography systems. Likewise, acid hydrolysis (5.6 M HCl, 110 degrees C, 2 hr) of the phosphorylated tryptic peptides revealed linkage of the phosphate to a tyrosine. Thus, A(*) protein cleaves single-stranded DNA and binds covalently to the 5'-phosphorylated terminus via a tyrosyl-dAMP phosphodiester bond.
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PMID:Cleavage of single-stranded DNA by the varphiX174 A protein: The A-single-stranded DNA covalent linkage. 1659 85


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