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:3.5.1.52 (PNGase F)
1,527 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Asparagine-linked oligosaccharides of stem bromelain glycopeptides were quantitatively released by digestion with the almond glycopeptidase which cleaves beta-aspartylglycosylamine linkage in glycopeptides with oligopeptide moieties. The primary structures of the two oligosaccharide components, (Man)3(Xyl)1(Fuc)1(GlcNAc)2 and (Man)2-(Xyl)1(Fuc)1(GlcNAc)2 were elucidated as Man alpha 1 leads to 6Man alpha 1 leads to 6[Xyl beta 1 leads to 2]Man beta 1 leads to 4GlcNAc beta 1 leads 4[Fuc alpha 1 leads to 3]GlcNAc and Man alpha 1 leads to 6[Xyl beta 1 leads to 2]Man beta 1 leads to 4 GlcNAc beta 1 leads to 4[Fuc alpha 1 leads to 3] GlcNAc, respectively.
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PMID:Complete structure of the carbohydrate moiety of stem bromelain. An application of the almond glycopeptidase for structural studies of glycopeptides. 50 Jun 6

The amino acid sequences of the kainate binding proteins (KBPs) from frog and chicken brain are homologous with the carboxy terminal half of the rat brain AMPA receptors. In this study, we have characterized the oligosaccharide side chains present on the KBPs from chicken and frog brain, and the AMPA receptors (GluR1, GluR2, and GluR3) from rat brain. Deglycosylation of the asparagine-linked carbohydrates present on the chicken, frog, and rat receptor subunits with N-glycanase, resulted in decreases in the relative molecular weights (M(r)) of 3.4, 3.4, and 5.1 kDa respectively. Thus the percent of asparagine linked carbohydrate (based on M(r) values derived from SDS polyacrylamide gels) of the 49 kDa chicken, the 48 kDa frog, and the 107 kDa receptor rat subunits is 6.9, 7.1, and 4.8 percent respectively. No shifts in the M(r) were detected after treatment with neuraminidase indicating that sialic acid does not appear to be a major component of these receptors. Lectin binding studies demonstrated that both asparagine-linked and serine/threonine-linked oligosaccharides were present in the chicken, frog, and rat proteins. The data indicate that at least one of the asparagine linked oligosaccharide side chains appear to be of the complex or non-bisected hybrid type in all three species. The similarities in the glycosyl moieties of the chicken and frog kainate KBPs and the rat brain AMPA receptors suggests that the homology in the amino acid sequences between these proteins may extend to homology in their oligosaccharide sides chains as well.
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PMID:Characterization of the oligosaccharide side chains on kainate binding proteins and AMPA receptors. 133 Feb 12

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

Chymotryptic glycopeptides were prepared from a honeybee (Apis mellifica) venom phospholipase A2 (E.C. 3.1.1.4) fraction, with high affinity towards lentil (Lens culinaris) lectin. Treatment of the glycopeptide mixture with peptide-N4-(N-acetyl-beta-glucosaminyl)asparagine amidase A, followed by HPLC fractionation, yielded two oligosaccharides, which were analysed by 500 MHz 1H-NMR spectroscopy to give the following structures [formula: see text] This is the first report on a naturally occurring glycoprotein N-glycan with two fucose residues linked to the asparagine-bound N-acetylglucosamine.
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PMID:Alpha 1-6(alpha 1-3)-difucosylation of the asparagine-bound N-acetylglucosamine in honeybee venom phospholipase A2. 134 12

The N-linked carbohydrate chains of the beta subunit of human chorionic gonadotropin (hCG-beta) isolated from the culture fluid of the choriocarcinoma cell line BeWo were released enzymatically by peptide-N4-(N-acetyl-beta-glucosaminyl)asparagine amidase F. Subsequently, the O-linked oligosaccharides were split off from the N-deglycosylated protein by mild alkaline borohydride treatment. The carbohydrate chains were purified in their intact sialylated forms by FPLC anion-exchange chromatography on Mono Q, HPLC on Lichrosorb-NH2, and high-pH anion-exchange chromatography on CarboPac PA1. 1H-NMR spectroscopic analysis of the major fractions demonstrates the occurrence of the following sialylated diantennary and triantennary N-linked oligosaccharides. Residues not written in bold letters are variably present. [formula: see text] The incidence of triantennary carbohydrate chains is much higher than in normal urinary hCG-beta (26% vs 2%). The same holds for the alpha 1-6-fucosylation of the asparagine-bound GlcNAc (95% vs 42%). The presence of a bisecting GlcNAc and the occurrence of alpha 2-6-linked Neu5Ac in the most abundant N-glycans, are new features for hCG-beta. The major O-linked carbohydrate chains identified are the tetrasaccharide Neu5Ac alpha 2-3Gal beta 1-3(Neu5Ac alpha 2-6)GalNAc-ol and the hexasaccharide Neu5Ac alpha 2-3Gal beta 1-4GlcNAc beta 1-6(Neu5Ac alpha 2-3Gal beta 1-3)GalNAc-ol, both also found in normal urinary hCG. In addition, two novel O-glycans were characterized: [formula: see text]
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PMID:The carbohydrate chains of the beta subunit of human chorionic gonadotropin produced by the choriocarcinoma cell line BeWo. Novel O-linked and novel bisecting-GlcNAc-containing N-linked carbohydrates. 137 31

A comparative study was undertaken to characterize the linkages of L-fucose in N-glycans of plasma membrane glycoproteins from Morris hepatoma 7777, host liver and kidney cortex, as well as from rat serum. After in-vivo radiolabelling of rats with L-[6-3H]fucose, the asparagine-linked carbohydrate chains were released from delipidated plasma membrane glycoproteins, as well as from serum glycoproteins, by enzymic digestion with peptide-N4-(N-acetyl-beta-glucosaminyl)asparagine amidase from Flavobacterium meningosepticum. They were then converted to their corresponding oligosaccharide alditols by reduction with sodium borohydride. Two specific alpha-L-fucosidases from almond emulsin and from Aspergillus niger, combined with affinity HPLC on immobilized Aleuria aurantia lectin were used to study the linkage of L-fucose in the oligosaccharide chains. Fucose alpha 1-2 linked to galactose, was present only in the plasma membrane of hepatoma 7777 (18% of total L-[3H]fucose in N-glycans), but was not expressed in host liver, kidney cortex and serum. None of the investigated sources contained an appreciable amount of fucose alpha 1-3/4 linked to N-acetyl-D-glucosamine. All the radioactively labelled oligosaccharides from host liver, kidney cortex and serum, but only 82% of these oligosaccharides from hepatoma, contained alpha-fucosyl residues linked at the C6 position of the proximal N-acetyl-D-glucosamine.
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PMID:Occurrence of alpha 1-2-fucosylation in membrane glycoproteins of Morris hepatoma 7777 but not in liver. Aberrant type of fucosylation in a malignant tissue. 139 74

Human skin fibroblast lines of the infantile form of neuronal ceroid lipofuscinosis and control lines were cultured in the presence of [3H]glucosamine plus [3H]mannose and [35S]methionine. The labeled glycoconjugates were compared by quantitative polyacrylamide gel electrophoresis in sodium dodecyl sulfate. The infantile form of the disease showed a 75% decrease of four glycoprotein components of M(r) 120-140 kDa. These components appeared to be N-linked glycoproteins as peptide-N4-(N-acetyl-beta-glucosaminyl) asparagine amidase (PNGase F) released 86-96% of the labeled carbohydrate from the labeled protein. These results suggest that the infantile form of this disease may be characterized by abnormalities in glycoconjugate metabolism leading to reduction of specific glycoproteins.
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PMID:Glycoprotein metabolism in neuronal ceroid lipofuscinosis fibroblasts. 141 45

Peptide-N4-(N-acetyl-beta-glucosaminyl) asparagine amidase F (PNGase F) and endo-beta-N-acetyl glucosaminidase F (Endo F) activities were monitored during cultivation of Flavobacterium meningosepticum using a new fluorescence-HPLC procedure based on a commercially available substrate. The PNGase F activity reached a maximum level at the end of the log phase and remained constant during the stationary phase, while Endo F continuously increased until late stationary phase. PNGase F obtained at the end of the log phase was less contaminated by other proteins compared with late stationary phase.
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PMID:Use of resorufin-labelled N-glycopeptide in a high-performance liquid chromatography assay to monitor endoglycosidase activities during cultivation of Flavobacterium meningosepticum. 142 35

Electrospray and tandem mass spectrometry are used to characterize underivatized oligosaccharides that have been digested from asparagine side chains of glycoproteins. Oligosaccharides that contain sialic acids were detected with the best sensitivity in the negative-ion detection mode whereas those that do not contain sialic acid were detected with the best sensitivity in the positive-ion detection mode. The positive-ion abundances of oligosaccharides were greatly enhanced in electrospray mass spectra by adding 10 mM sodium acetate or ammonium acetate to the sample solvent. Tandem mass spectrometry was used to determine primary structural features of the oligosaccharides. Methodology that has been developed on branched high-mannose, hybrid, and complex carbohydrate standards was applied to a mixture of oligosaccharides that were digested with N-glycanase from the glycoprotein, ovalbumin. The composition and relative abundances of individual oligosaccharides obtained from the electrospray mass spectrum compare favorably to those obtained by anion-exchange chromatography/pulsed amperometric detection and by gel permeation chromatography of the oligosaccharides after radiolabelling the reducing end of the carbohydrates. The oligosaccharide content of ovalbumin was independently determined from the heterogeneity observed in the electrospray mass spectrum of the intact 44-kDa glycoprotein. Comparison of the oligosaccharide compositions determined before and after enzymatic digestion shows a selective digestion of high-mannose and low molecular weight oligosaccharides by N-glycanase.
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PMID:Characterization of N-linked oligosaccharides by electrospray and tandem mass spectrometry. 150 19

Variant surface glycoproteins (VSGs) of Trypanosoma brucei contain two distinct glycosylation sites: (1) N-linked glycans within the protein portion of the molecules, and (2) the glycosyl-phosphatidylinositol (GPI) membrane anchor. Since galactose residues show uncommon alpha-glycosidic linkages in the GPI membrane anchor, we were prompted to investigate galactosylation of the GPI anchor. On comparing a trypanosome clone galactosylated exclusively in N-glycans (clone MITat 1.5) with clones galactosylated predominantly in the glypiated membrane anchor (clones MITat 1.4, MITat 1.6 and AnTat 1.8), clone MITat 1.5 showed a 10-fold increased enzyme activity when using a protocol including Triton X-100 to assay UDPgalactose:N-acetylglucosaminyl glycopeptide beta 1,4-galactosyltransferase (EC 2.4.1.38). Only the VSG of clone MITat 1.5 could be radiochemically labelled with UDP[14C]galactose, and galactosylation of N-glycans was confirmed by digestion with peptide-N4-(N-acetylglucosaminyl)asparagine amidase (PNGase F). However, in a modified enzyme assay without detergent, galactosyltransferase activity was increased considerably (15-fold) in clone MITat 1.4. VSG galactosylation of clones MITat 1.4, MITat 1.6 and AnTat 1.8 was readily detected by fluorography of the respective SDS/polyacrylamide gels, suggesting that galactosyltransferase activity modifies the VSG membrane anchor in these clones. In this case, [14C]galactose labelling of immunoprecipitated VSG (clone MITat 1.4) was resistant to the release of N-glycans by PNGase F treatment, and thus revealed galactosylation in vitro of a VSG membrane anchor. Exoglycosidase digestions of VSG MITat 1.4 confirmed the presence of alpha-linked galactose residues. We suggest that these specific alpha-galactosyltransferases are inhibited by the action of detergent, but can be activated in a detergent-free buffer system.
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PMID:Identification of two distinct galactosyltransferase activities acting on the variant surface glycoprotein of Trypanosoma brucei. 153 12


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