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Erika Aberg - One of the best experts on this subject based on the ideXlab platform.
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structure of the n linked glycan present on multiple glycoproteins in the gram negative bacterium campylobacter jejuni
Journal of Biological Chemistry, 2002Co-Authors: Martin N Young, Jeanrobert Brisson, John Kelly, David C Watson, Luc Tessier, Patricia Lanthier, Harold C Jarrell, Nicolas Cadotte, Frank St Michael, Erika AbergAbstract:Mass spectrometry investigations of partially purified Campylobacter jejuni protein PEB3 showed it to be partially modified with an Asn-linked glycan with a mass of 1406 Da and composed of one hexose, five N-acetylhexosamines and a species of mass 228 Da, consistent with a trideoxydiacetamidohexose. By means of soybean lectin affinity chromatography, a mixture of glycoproteins was obtained from a Glycine extract, and two-dimensional gel proteomics analysis led to the identification of at least 22 glycoproteins, predominantly annotated as periplasmic proteins. Glycopeptides were prepared from the glycoprotein mixture by Pronase digestion and gel filtration. The structure of the glycan was determined by using nano-NMR techniques to be GalNAc-alpha1,4-GalNAc-alpha1,4-[Glcbeta1,3-]GalNAc-alpha1,4-GalNAc-alpha1,4-GalNAc-alpha1,3-Bac-beta1,N-Asn-Xaa, where Bac is bacillosamine, 2,4-diacetamido-2,4,6-trideoxyglucopyranose. Protein glycosylation was abolished when the pglB gene was mutated, providing further evidence that the enzyme encoded by this gene is responsible for formation of the glycopeptide N-linkage. Comparison of the pgl locus with that of Neisseria meningitidis suggested that most of the homologous genes are probably involved in the biosynthesis of bacillosamine.
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structure of the n linked glycan present on multiple glycoproteins in the gram negative bacterium campylobacter jejuni
Journal of Biological Chemistry, 2002Co-Authors: Martin N Young, Jeanrobert Brisson, David C Watson, Luc Tessier, Patricia Lanthier, Harold C Jarrell, Nicolas Cadotte, Frank St Michael, John F Kelly, Erika AbergAbstract:Abstract Mass spectrometry investigations of partially purified Campylobacter jejuni protein PEB3 showed it to be partially modified with an Asn-linked glycan with a mass of 1406 Da and composed of one hexose, five N-acetylhexosamines and a species of mass 228 Da, consistent with a trideoxydiacetamidohexose. By means of soybean lectin affinity chromatography, a mixture of glycoproteins was obtained from a Glycine extract, and two-dimensional gel proteomics analysis led to the identification of at least 22 glycoproteins, predominantly annotated as periplasmic proteins. Glycopeptides were prepared from the glycoprotein mixture by Pronase digestion and gel filtration. The structure of the glycan was determined by using nano-NMR techniques to be GalNAc-α1,4-GalNAc-α1,4-[Glcβ1,3-]GalNAc-α1,4-GalNAc-α1,4-GalNAc-α1,3-Bac-β1,N-Asn-Xaa, where Bac is bacillosamine, 2,4-diacetamido-2,4,6-trideoxyglucopyranose. Protein glycosylation was abolished when the pglB gene was mutated, providing further evidence that the enzyme encoded by this gene is responsible for formation of the glycopeptide N-linkage. Comparison of thepgl locus with that of Neisseria meningitidissuggested that most of the homologous genes are probably involved in the biosynthesis of bacillosamine.
Martin N Young - One of the best experts on this subject based on the ideXlab platform.
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structure of the n linked glycan present on multiple glycoproteins in the gram negative bacterium campylobacter jejuni
Journal of Biological Chemistry, 2002Co-Authors: Martin N Young, Jeanrobert Brisson, John Kelly, David C Watson, Luc Tessier, Patricia Lanthier, Harold C Jarrell, Nicolas Cadotte, Frank St Michael, Erika AbergAbstract:Mass spectrometry investigations of partially purified Campylobacter jejuni protein PEB3 showed it to be partially modified with an Asn-linked glycan with a mass of 1406 Da and composed of one hexose, five N-acetylhexosamines and a species of mass 228 Da, consistent with a trideoxydiacetamidohexose. By means of soybean lectin affinity chromatography, a mixture of glycoproteins was obtained from a Glycine extract, and two-dimensional gel proteomics analysis led to the identification of at least 22 glycoproteins, predominantly annotated as periplasmic proteins. Glycopeptides were prepared from the glycoprotein mixture by Pronase digestion and gel filtration. The structure of the glycan was determined by using nano-NMR techniques to be GalNAc-alpha1,4-GalNAc-alpha1,4-[Glcbeta1,3-]GalNAc-alpha1,4-GalNAc-alpha1,4-GalNAc-alpha1,3-Bac-beta1,N-Asn-Xaa, where Bac is bacillosamine, 2,4-diacetamido-2,4,6-trideoxyglucopyranose. Protein glycosylation was abolished when the pglB gene was mutated, providing further evidence that the enzyme encoded by this gene is responsible for formation of the glycopeptide N-linkage. Comparison of the pgl locus with that of Neisseria meningitidis suggested that most of the homologous genes are probably involved in the biosynthesis of bacillosamine.
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structure of the n linked glycan present on multiple glycoproteins in the gram negative bacterium campylobacter jejuni
Journal of Biological Chemistry, 2002Co-Authors: Martin N Young, Jeanrobert Brisson, David C Watson, Luc Tessier, Patricia Lanthier, Harold C Jarrell, Nicolas Cadotte, Frank St Michael, John F Kelly, Erika AbergAbstract:Abstract Mass spectrometry investigations of partially purified Campylobacter jejuni protein PEB3 showed it to be partially modified with an Asn-linked glycan with a mass of 1406 Da and composed of one hexose, five N-acetylhexosamines and a species of mass 228 Da, consistent with a trideoxydiacetamidohexose. By means of soybean lectin affinity chromatography, a mixture of glycoproteins was obtained from a Glycine extract, and two-dimensional gel proteomics analysis led to the identification of at least 22 glycoproteins, predominantly annotated as periplasmic proteins. Glycopeptides were prepared from the glycoprotein mixture by Pronase digestion and gel filtration. The structure of the glycan was determined by using nano-NMR techniques to be GalNAc-α1,4-GalNAc-α1,4-[Glcβ1,3-]GalNAc-α1,4-GalNAc-α1,4-GalNAc-α1,3-Bac-β1,N-Asn-Xaa, where Bac is bacillosamine, 2,4-diacetamido-2,4,6-trideoxyglucopyranose. Protein glycosylation was abolished when the pglB gene was mutated, providing further evidence that the enzyme encoded by this gene is responsible for formation of the glycopeptide N-linkage. Comparison of thepgl locus with that of Neisseria meningitidissuggested that most of the homologous genes are probably involved in the biosynthesis of bacillosamine.
Beatriz Lopezcorcuera - One of the best experts on this subject based on the ideXlab platform.
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calnexin assisted biogenesis of the neuronal Glycine transporter 2 glyt2
PLOS ONE, 2013Co-Authors: Beatriz Lopezcorcuera, Esther Arribasgonzalez, Pablo AlonsotorresAbstract:The neuronal transporter GlyT2 is a polytopic, 12-transmembrane domain, plasma membrane glycoprotein involved in the removal and recycling of synaptic Glycine from inhibitory synapses. Mutations in the human GlyT2 gene (SLC6A5) that cause deficient Glycine transport or defective GlyT2 trafficking are the second most common cause of hyperekplexia or startle disease. In this study we examined several aspects of GlyT2 biogenesis that involve the endoplasmic reticulum chaperone calnexin (CNX). CNX binds transiently to an intermediate under-glycosylated transporter precursor and facilitates GlyT2 processing. In cells expressing GlyT2, transporter accumulation and transport activity were attenuated by siRNA-mediated CNX knockdown and enhanced by CNX overexpression. GlyT2 binding to CNX was mediated by glycan and polypeptide-based interactions as revealed by pharmacological approaches and the behavior of GlyT2 N-glycan-deficient mutants. Moreover, transporter folding appeared to be stabilized by N-glycans. Co-expression of CNX and a fully non-glycosylated mutant rescues Glycine transport but not mutant surface expression. Hence, CNX discriminates between different conformational states of GlyT2 displaying a lectin-independent chaperone activity. GlyT2 wild-type and mutant transporters were finally degraded in the lysosome. Our findings provide further insight into GlyT2 biogenesis, and a useful framework for the study of newly synthesized GlyT2 transporters bearing hyperekplexia mutations.
Suzanne Walker - One of the best experts on this subject based on the ideXlab platform.
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peptidoglycan cross linking preferences of staphylococcus aureus penicillin binding proteins have implications for treating mrsa infections
Journal of the American Chemical Society, 2017Co-Authors: Veerasak Srisuknimit, Yuan Qiao, Kaitlin Schaefer, Daniel Kahne, Suzanne WalkerAbstract:Methicillin-resistant Staphylococcus aureus (MRSA) infections are a global public health problem. MRSA strains have acquired a non-native penicillin-binding protein called PBP2a that cross-links peptidoglycan when the native S. aureus PBPs are inhibited by β-lactams. It has been proposed that the native S. aureus PBPs can use cell wall precursors having different Glycine branch lengths (penta-, tri-, or monoGlycine), while PBP2a can only cross-link peptidoglycan strands bearing a complete pentaGlycine branch. This hypothesis has never been tested because the necessary substrates have not been available. Here, we compared the ability of PBP2a and two native S. aureus transpeptidases to cross-link peptidoglycan strands bearing different Glycine branches. We show that purified PBP2a can cross-link glycan strands bearing penta- and triGlycine, but not monoGlycine, and experiments in cells provide support for these findings. Because PBP2a cannot cross-link peptidoglycan containing monoGlycine, this study impli...
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Peptidoglycan Cross-Linking Preferences of Staphylococcus aureus Penicillin-Binding Proteins Have Implications for Treating MRSA Infections
2017Co-Authors: Veerasak Srisuknimit, Yuan Qiao, Kaitlin Schaefer, Daniel Kahne, Suzanne WalkerAbstract:Methicillin-resistant Staphylococcus aureus (MRSA) infections are a global public health problem. MRSA strains have acquired a non-native penicillin-binding protein called PBP2a that cross-links peptidoglycan when the native S. aureus PBPs are inhibited by β-lactams. It has been proposed that the native S. aureus PBPs can use cell wall precursors having different Glycine branch lengths (penta-, tri-, or monoGlycine), while PBP2a can only cross-link peptidoglycan strands bearing a complete pentaGlycine branch. This hypothesis has never been tested because the necessary substrates have not been available. Here, we compared the ability of PBP2a and two native S. aureus transpeptidases to cross-link peptidoglycan strands bearing different Glycine branches. We show that purified PBP2a can cross-link glycan strands bearing penta- and triGlycine, but not monoGlycine, and experiments in cells provide support for these findings. Because PBP2a cannot cross-link peptidoglycan containing monoGlycine, this study implicates the enzyme (FemA) that extends the monoGlycine branch to triGlycine on Lipid II as an ideal target for small molecules that restore sensitivity of MRSA to β-lactams
Shuh-chyung Song - One of the best experts on this subject based on the ideXlab platform.
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interaction of a human blood group sd a tamm horsfall glycoprotein with applied lectins
FEBS Letters, 1996Co-Authors: Winifred M. Watkins, Chie-pein Chen, Shuh-chyung SongAbstract:Abstract Unlike the human blood group Sd(a+) Tamm-Horsfall glycoprotein (THGP), the Sd(a−) one lacks terminal GalNAcβ1 → residues at the nonreducing ends. The binding properties of this glycoprotein and its asialo product with lectins were characterized by quantitative precipitin (QPA) and precipitin inhibition assays. Among 20 lectins tested by QPA, both native and asialo Sd(a−) THGP reacted best with Abrus precatorius and Ricinus communis and completely precipitated the lectin added. They also precipitated well Wistaria floribunda (WFA), Glycine max (SBA), Bauhinia purpurea alba , abrin-a and ricin, all of which recognize the Galβ1 → 4GlcNacβ1 → sequence, although at different strength. The lectin-glycan interactions were inhibited by Galβ1 → 4GlcNAc and Galβ1 → 4Glc. When the precipitability of Sd(a−) THGP was compared with that of the Sd(a+) phenotype, the native Sd(a−) THGP exhibited a 40% lesser affinity for WFA, SBA, WGA and mistletoe lectin-I (ML-I). Mapping the precipitation and inhibition profiles of the present study and the results of THGP Sd(a+), it is concluded that Sd(a−) THGP showed a strongly diminished affinity for GalNAcβ1 → active lectins (SBA and WFA) than the Sd(a+) phenotype.