Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:3.5.1.52 (PNGase F)
 1,527 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Saccharomyces cerevisiae contains an amphiphilic cAMP-binding glycoprotein at the outer face of the plasma membrane (M(r) = 54,000). It is converted to a hydrophilic form by treatment with glycosyl-phosphatidylinositol-specific phospholipases C and D (GPI-PLC/D), suggesting membrane anchorage by a covalently bound glycolipid. Determination of the constituents of the purified anchor by gas-liquid chromatography and amino acid analysis reveals the presence of glycerol, myo-inositol, glucosamine, galactose, mannose, ethanolamine, and asparagine (as the carboxyl-terminal amino acid of the Pronase-digested protein to which the anchor is attached). Complementary results are obtained by metabolic labeling, indicating that fatty acids and phosphorus are additional anchor constituents. The phosphorus is resistant to alkaline phosphatase, whereas approximately half is lost from the protein after treatment with GPI-PLD or nitrous acid, and all is removed by aqueous HF indicating the presence of two phosphodiester bonds. Inhibition of N-glycosylation by tunicamycin or removal of protein-bound glycan chains by N-glycanase or Pronase does not abolish radiolabeling of the anchor structure by any of the above compounds. Analysis of the products obtained after sequential enzymic and chemical degradation of the anchor agrees with the arrangement of constituents in GPIs from higher eucaryotes. Evidence for anchorage of the yeast cAMP-binding protein by a GPI anchor is strengthened additionally by the reactivity of the GPI-PLC-cleaved anchor with antibodies directed against the cross-reacting determinant of trypanosomal variant surface glycoproteins.
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PMID:The cAMP-binding ectoprotein from Saccharomyces cerevisiae is membrane-anchored by glycosyl-phosphatidylinositol. 133 92

Molecular ions and fragment ions of underivatized and permethylated oligosaccharides derived from human urinary kallikrein and some model glycoproteins gave information about the sugar composition and arrangement of sugars. These ions were conveniently created by FAB-MS in a JEOL JMS-HX110 high field high resolution mass spectrometer. Glycoprotein samples were digested with N-glycanase and the asparagine(Asn)-linked oligosaccharides were separated from polypeptides by Sephadex G-50 chromatography. The mixture of oligosaccharides was converted to the reduced p-aminobenzoic ethyl ester (ABEE) derivative and the components separated by HPLC on an ion-exchange (AX-10) column. Individual components were analyzed by negative FAB-MS using glycerol as a matrix. Permethylated oligosaccharides were also analyzed by positive FAB-MS.
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PMID:Fast atom bombardment mass spectrometry (FAB-MS): analysis of complex carbohydrate chains of tissue kallikreins. 260 19

New sialic acid-specific lectin has been isolated from culture supernatant of the protozoan Tritrichomonas mobilensis. It was purified by adsorption by erythrocytes or bovine submaxillary gland mucin (BSM)-Sepharose affinity chromatography. The T. mobilensis lectin (TML) does not require bivalent cations for activity and agglutinates all human erythrocytes. The lectin forms multimeric complexes with molecular mass 556 and 491 kDa as determined by size-exclusion chromatography. SDS/PAGE under reducing conditions disclosed a large band of 343 kDa and three bands of 246, 265 and 286 kDa which, after denaturation with urea, were split into three subunits of 56, 61 and 66 kDa; under non-reducing conditions there were two bands, of 360 and 260 kDa. Western blots performed with anti-TML monoclonal antibodies revealed bands identical with those in the silver-stained gels, suggesting homogeneity of the BSM -Sepharose-purified lectin. TML is a highly glycosylated protein with approx. 8% of N-linked glycosides found by protein-N-glycanase F treatment; the total amount of saccharides revealed by chemical deglycosylation was 20%. Haemagglutination-inhibition studies documented exclusive specificity for sialic acid (NeuAc). Both (alpha 2-->6)- and (alpha 2-->3)-linked and free NeuAc were eight times more potent inhibitors than N-glycolylneuraminic acid. The lectin does not require O-acetyl groups on NeuAc for recognition. A spectrum of mono- and oligo-saccharides other than sialic acid had no inhibitory effect at 200 mM. Anti-TML monoclonal antibodies strongly inhibited the lectin activity. TML was stable at temperatures below 4 degrees C and lyophilized with 3% (w/w) glycerol.
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PMID:Purification and characterization of a sialic acid-specific lectin from Tritrichomonas mobilensis. 817 92