Show legend Show as text

Structure type: polymer chemical repeating unit
Compound class: O-polysaccharide
Contained glycoepitopes: IEDB_133754,IEDB_136105,IEDB_142488,IEDB_144998,IEDB_146664,IEDB_158539,IEDB_225177,IEDB_885823,IEDB_983931,SB_192

• Article ID: 4329
  Knirel YA "Structure of O-antigens" - Book: Bacterial lipopolysaccharides: Structure, chemical synthesis, biogenesis and interaction with host cells (2011) Chapter 3, 41-115
  

  The lipopolysaccharide (LPS) is the major constituent of the outer leaflet of the outer membrane of Gram-negative bacteria. Its lipid A moiety is embedded in the membrane and serves as an anchor for the rest of the LPS molecule. The outermost repetitive glycan region of the LPS is linked to the lipid A through a core oligosaccharide (OS), and is designated as the O-specific polysaccharide (O-polysaccharide, OPS) or O-antigen. The O-antigen is the most variable portion of the LPS and provides serological specificity, which is used for bacterial serotyping. The OPS also provides protection to the microorganisms from host defenses such as complement mediated killing and phagocytosis, and is involved in interactions of bacteria with plants and bacteriophages. Studies of the OPSs ranging from the elucidation of their chemical structures and conformations to their biological and physico-chemical properties help improving classification schemes of Gram-negative bacteria. Furthermore, these studies contributed to a better understanding of the mechanisms of pathogenesis of infectious diseases, as well as provided information to develop novel vaccines and diagnostic reagents.

  Lipopolysaccharide, synthesis, lipopolysaccharides, structure, Bacterial, host, O-antigen, O antigen, cell, O antigens, O-antigens, chemical, interaction, cells, PDF, chemical synthesis, biogenesis

  Publication DOI: 10.1007/978-3-7091-0733-1_3
  Publisher: Springer
  Correspondence: knirel@ioc.ac.ru
  Editors: Knirel YA, Valvano MA
  Institutions: Zelinsky Institute of Organic Chemistry, Russian Academy of Sciences, Moscow, Russia
  
   
  
  Xanthomonas campestris pv. pruni
  CSDB ID 27805 (all data & tools)

Show legend Show as text

Structure type: oligomer
Contained glycoepitopes: IEDB_114701,IEDB_115136,IEDB_136044,IEDB_136095,IEDB_136906,IEDB_137472,IEDB_140630,IEDB_141794,IEDB_142487,IEDB_142488,IEDB_144998,IEDB_146664,IEDB_151528,IEDB_167188,IEDB_174332,IEDB_190606,IEDB_423153,IEDB_983931,SB_165,SB_166,SB_187,SB_192,SB_195,SB_6,SB_7,SB_88

• Article ID: 5627
  Dembitsky VM, Rezanka T "Metabolites produced by nitrogen-fixing Nostoc species" - Folia Microbiologica 50(5) (2005) 363-391
  

  This paper provides a comprehensive overview of metabolites, including lipids and lipid-like compounds, boron-containing macrocycles, arsenolipids, oligopeptides and amino acid derivatives, produced by cyanobacteria of the genus Nostoc

  cyanobacteria, lipids, metabolites, Nostoc

  NCBI PubMed ID: 16475497
  Publication DOI: 10.1007/bf02931419
  Journal NLM ID: 0376757
  Publisher: New York: Springer
  Correspondence: rezanka@biomed.cas.cz
  Institutions: Institute of Microbiology, Academy of Sciences of the Czech Republic, Prague, Czech, Department of Organic Chemistry, The Hebrew University of Jerusalem, Jerusalem, Israel
  
   
  
  Nostoc commune HB 261
  CSDB ID 47820 (all data & tools)

Show legend Show as text

Structure type: oligomer
Contained glycoepitopes: IEDB_114701,IEDB_115136,IEDB_136044,IEDB_136095,IEDB_136906,IEDB_137472,IEDB_140630,IEDB_141794,IEDB_142487,IEDB_142488,IEDB_144998,IEDB_146664,IEDB_151528,IEDB_167188,IEDB_174332,IEDB_190606,IEDB_423153,IEDB_983931,SB_165,SB_166,SB_187,SB_192,SB_195,SB_6,SB_7,SB_88

• Article ID: 5627
  Dembitsky VM, Rezanka T "Metabolites produced by nitrogen-fixing Nostoc species" - Folia Microbiologica 50(5) (2005) 363-391
  

  This paper provides a comprehensive overview of metabolites, including lipids and lipid-like compounds, boron-containing macrocycles, arsenolipids, oligopeptides and amino acid derivatives, produced by cyanobacteria of the genus Nostoc

  cyanobacteria, lipids, metabolites, Nostoc

  NCBI PubMed ID: 16475497
  Publication DOI: 10.1007/bf02931419
  Journal NLM ID: 0376757
  Publisher: New York: Springer
  Correspondence: rezanka@biomed.cas.cz
  Institutions: Institute of Microbiology, Academy of Sciences of the Czech Republic, Prague, Czech, Department of Organic Chemistry, The Hebrew University of Jerusalem, Jerusalem, Israel
  
   
  
  Nostoc commune HB 261
  CSDB ID 47821 (all data & tools)

Show legend Show as text

Structure type: polymer chemical repeating unit
Contained glycoepitopes: IEDB_114701,IEDB_115136,IEDB_115576,IEDB_130701,IEDB_1394182,IEDB_140116,IEDB_140630,IEDB_144983,IEDB_145668,IEDB_152206,IEDB_164174,IEDB_167188,IEDB_174332,IEDB_423153,IEDB_76933,IEDB_983930,SB_197,SB_44,SB_67,SB_72

• Article ID: 6882
  De Baets S, Vandamme EJ "Extracellular Tremella polysaccharides: structure, properties and applications" - Biotechnology Letters 23 (2001) 1361-1366
  

  Tremella sp. is a yeast-like fungus from which polysaccharides can be isolated from either the yeast or the fungus phase, depending on the species. All of the polymers synthesized by these organisms consist of a mannan backbone to which small xylose side chains and glucuronic acid are attached. The main interest in these glucuronoxylomannans is their application in medicine to enhance the immune system.

  Tremella mesenterica, Glucuronoxylomannan, hypoglycemic, immuno-modulatory, Tremella aurantia, Tremella fuciformis, yeast polysaccharides

  Publication DOI: 10.1023/A:1011645724220
  Journal NLM ID: 8008051
  Publisher: Kluwer Academic Publishers
  Correspondence: Sophie.DeBaets@rug.ac.be
  Institutions: Laboratory of Industrial Microbiology and Biocatalysis, Department of Biochemical and Microbial Technology, Ghent University, Coupure links 653, B-9000 Gent, Belgium
  
   
  
  Tremella aurantia Schw. ex Fr.
  CSDB ID 40858 (all data & tools)

Show legend Show as text

Structure type: oligomer
Contained glycoepitopes: IEDB_114701,IEDB_130701,IEDB_136044,IEDB_137472,IEDB_1394182,IEDB_141794,IEDB_144983,IEDB_145668,IEDB_152206,IEDB_164174,IEDB_167188,IEDB_174332,IEDB_190606,IEDB_983930,SB_165,SB_166,SB_187,SB_195,SB_197,SB_44,SB_67,SB_7,SB_72,SB_88

• Article ID: 6912
  Penha CV, Todeschini AR, Lopes-Bezerra LM, Wait R, Jones C, Mattos KA, Heise N, Mendonça-Previato L, Previato JO "Characterization of novel structures of mannosylinositolphosphorylceramides from the yeast forms of Sporothrix schenckii" - European Journal of Biochemistry 268 (2001) 4243-4250
  

  Novel structures of glycoinositolphosphorylceramide (GIPC) from the infective yeast form of Sporothrix schenckii were determined by methylation analysis, mass spectrometry and NMR spectroscopy. The lipid portion was characterized as a ceramide composed of C-18 phytosphingosine N-acylated by either 2-hydroxylignoceric acid (80%), lignoceric (15%) or 2,3-dihydroxylignoceric acids (5%). The ceramide was linked through a phosphodiester to myo-inositol (Ins) which is substituted on position O-6 by an oligomannose chain. GIPC-derived Ins oligomannosides were liberated by ammonolysis and characterized as: Manp-α1→6Ins; Manp-α1→3Manp-α1→6Ins; Manp-α1→6Manp-α1→3Manp-α1→3Manp-α1→6Ins; Manp-α1→2Manp-α1→6Manp-α1→3Manp-α1→3Manp-α1→6Ins. These structures comprise a novel family of fungal GIPC, as they contain the Manp-α1→6Ins substructure, which has not previously been characterized unambigously, and may be acylated with a 2,3-dihydroxylignoceric fatty acid, a feature hitherto undescribed in fungal lipids.

  NMR, mass spectrometry, Sporothrix schenckii, glycoinositolphosphorylceramide

  Publication DOI: 10.1046/j.1432-1327.2001.02339.x
  Journal NLM ID: 0107600
  Publisher: Oxford, UK: Blackwell Science Ltd. on behalf of the Federation of European Biochemical Societies
  Correspondence: immglup@microbio.ufrj.br
  Institutions: Departamento de Biologia Celular e Genética and Departamento de Bioquímica, UERJ, Rio de Janeiro, Brasil, Kennedy Institute for Rheumatology, Imperial College, London, UK, Laboratory for Molecular Structure, NIBSC, Herts, UK, Instituto de Microbiologia, CCS-Bloco I, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brasil
  Methods: 13C NMR, 1H NMR, gel filtration, GC-MS, GLC, MALDI-MS, HPLC, TOCSY, methylation analysis, HMBC, HMQC, NOESY, ammonolysis
  
   
  
  Cryptococcus neoformans
  CSDB ID 40671 (all data & tools)

Show legend Show as text

Structure type: oligomer
Contained glycoepitopes: IEDB_114701,IEDB_130701,IEDB_136044,IEDB_137472,IEDB_1394182,IEDB_140116,IEDB_141793,IEDB_141794,IEDB_144983,IEDB_145668,IEDB_152206,IEDB_153220,IEDB_164174,IEDB_167188,IEDB_174332,IEDB_190606,IEDB_983930,SB_165,SB_166,SB_187,SB_195,SB_197,SB_198,SB_44,SB_67,SB_7,SB_72,SB_88

• Article ID: 6912
  Penha CV, Todeschini AR, Lopes-Bezerra LM, Wait R, Jones C, Mattos KA, Heise N, Mendonça-Previato L, Previato JO "Characterization of novel structures of mannosylinositolphosphorylceramides from the yeast forms of Sporothrix schenckii" - European Journal of Biochemistry 268 (2001) 4243-4250
  

  Novel structures of glycoinositolphosphorylceramide (GIPC) from the infective yeast form of Sporothrix schenckii were determined by methylation analysis, mass spectrometry and NMR spectroscopy. The lipid portion was characterized as a ceramide composed of C-18 phytosphingosine N-acylated by either 2-hydroxylignoceric acid (80%), lignoceric (15%) or 2,3-dihydroxylignoceric acids (5%). The ceramide was linked through a phosphodiester to myo-inositol (Ins) which is substituted on position O-6 by an oligomannose chain. GIPC-derived Ins oligomannosides were liberated by ammonolysis and characterized as: Manp-α1→6Ins; Manp-α1→3Manp-α1→6Ins; Manp-α1→6Manp-α1→3Manp-α1→3Manp-α1→6Ins; Manp-α1→2Manp-α1→6Manp-α1→3Manp-α1→3Manp-α1→6Ins. These structures comprise a novel family of fungal GIPC, as they contain the Manp-α1→6Ins substructure, which has not previously been characterized unambigously, and may be acylated with a 2,3-dihydroxylignoceric fatty acid, a feature hitherto undescribed in fungal lipids.

  NMR, mass spectrometry, Sporothrix schenckii, glycoinositolphosphorylceramide

  Publication DOI: 10.1046/j.1432-1327.2001.02339.x
  Journal NLM ID: 0107600
  Publisher: Oxford, UK: Blackwell Science Ltd. on behalf of the Federation of European Biochemical Societies
  Correspondence: immglup@microbio.ufrj.br
  Institutions: Departamento de Biologia Celular e Genética and Departamento de Bioquímica, UERJ, Rio de Janeiro, Brasil, Kennedy Institute for Rheumatology, Imperial College, London, UK, Laboratory for Molecular Structure, NIBSC, Herts, UK, Instituto de Microbiologia, CCS-Bloco I, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brasil
  Methods: 13C NMR, 1H NMR, gel filtration, GC-MS, GLC, MALDI-MS, HPLC, TOCSY, methylation analysis, HMBC, HMQC, NOESY, ammonolysis
  
   
  
  Cryptococcus neoformans
  CSDB ID 40672 (all data & tools)

Show legend Show as text

Structure type: oligomer
Contained glycoepitopes: IEDB_114701,IEDB_130701,IEDB_136044,IEDB_137472,IEDB_1394182,IEDB_140116,IEDB_141793,IEDB_141794,IEDB_141828,IEDB_144983,IEDB_145668,IEDB_152206,IEDB_153220,IEDB_164174,IEDB_167188,IEDB_174332,IEDB_190606,IEDB_76933,IEDB_983930,SB_165,SB_166,SB_187,SB_195,SB_197,SB_198,SB_44,SB_67,SB_7,SB_72,SB_88

• Article ID: 6912
  Penha CV, Todeschini AR, Lopes-Bezerra LM, Wait R, Jones C, Mattos KA, Heise N, Mendonça-Previato L, Previato JO "Characterization of novel structures of mannosylinositolphosphorylceramides from the yeast forms of Sporothrix schenckii" - European Journal of Biochemistry 268 (2001) 4243-4250
  

  Novel structures of glycoinositolphosphorylceramide (GIPC) from the infective yeast form of Sporothrix schenckii were determined by methylation analysis, mass spectrometry and NMR spectroscopy. The lipid portion was characterized as a ceramide composed of C-18 phytosphingosine N-acylated by either 2-hydroxylignoceric acid (80%), lignoceric (15%) or 2,3-dihydroxylignoceric acids (5%). The ceramide was linked through a phosphodiester to myo-inositol (Ins) which is substituted on position O-6 by an oligomannose chain. GIPC-derived Ins oligomannosides were liberated by ammonolysis and characterized as: Manp-α1→6Ins; Manp-α1→3Manp-α1→6Ins; Manp-α1→6Manp-α1→3Manp-α1→3Manp-α1→6Ins; Manp-α1→2Manp-α1→6Manp-α1→3Manp-α1→3Manp-α1→6Ins. These structures comprise a novel family of fungal GIPC, as they contain the Manp-α1→6Ins substructure, which has not previously been characterized unambigously, and may be acylated with a 2,3-dihydroxylignoceric fatty acid, a feature hitherto undescribed in fungal lipids.

  NMR, mass spectrometry, Sporothrix schenckii, glycoinositolphosphorylceramide

  Publication DOI: 10.1046/j.1432-1327.2001.02339.x
  Journal NLM ID: 0107600
  Publisher: Oxford, UK: Blackwell Science Ltd. on behalf of the Federation of European Biochemical Societies
  Correspondence: immglup@microbio.ufrj.br
  Institutions: Departamento de Biologia Celular e Genética and Departamento de Bioquímica, UERJ, Rio de Janeiro, Brasil, Kennedy Institute for Rheumatology, Imperial College, London, UK, Laboratory for Molecular Structure, NIBSC, Herts, UK, Instituto de Microbiologia, CCS-Bloco I, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brasil
  Methods: 13C NMR, 1H NMR, gel filtration, GC-MS, GLC, MALDI-MS, HPLC, TOCSY, methylation analysis, HMBC, HMQC, NOESY, ammonolysis
  
   
  
  Cryptococcus neoformans
  CSDB ID 40673 (all data & tools)

Show legend Show as text

Structure type: oligomer
Contained glycoepitopes: IEDB_114701,IEDB_130701,IEDB_136044,IEDB_136104,IEDB_137472,IEDB_1394182,IEDB_140116,IEDB_141793,IEDB_141794,IEDB_141828,IEDB_141829,IEDB_141831,IEDB_143632,IEDB_144983,IEDB_145668,IEDB_152206,IEDB_153220,IEDB_164174,IEDB_167188,IEDB_174332,IEDB_190606,IEDB_76933,IEDB_983930,SB_136,SB_165,SB_166,SB_187,SB_191,SB_195,SB_196,SB_197,SB_198,SB_44,SB_67,SB_7,SB_72,SB_88

• Article ID: 6912
  Penha CV, Todeschini AR, Lopes-Bezerra LM, Wait R, Jones C, Mattos KA, Heise N, Mendonça-Previato L, Previato JO "Characterization of novel structures of mannosylinositolphosphorylceramides from the yeast forms of Sporothrix schenckii" - European Journal of Biochemistry 268 (2001) 4243-4250
  

  Novel structures of glycoinositolphosphorylceramide (GIPC) from the infective yeast form of Sporothrix schenckii were determined by methylation analysis, mass spectrometry and NMR spectroscopy. The lipid portion was characterized as a ceramide composed of C-18 phytosphingosine N-acylated by either 2-hydroxylignoceric acid (80%), lignoceric (15%) or 2,3-dihydroxylignoceric acids (5%). The ceramide was linked through a phosphodiester to myo-inositol (Ins) which is substituted on position O-6 by an oligomannose chain. GIPC-derived Ins oligomannosides were liberated by ammonolysis and characterized as: Manp-α1→6Ins; Manp-α1→3Manp-α1→6Ins; Manp-α1→6Manp-α1→3Manp-α1→3Manp-α1→6Ins; Manp-α1→2Manp-α1→6Manp-α1→3Manp-α1→3Manp-α1→6Ins. These structures comprise a novel family of fungal GIPC, as they contain the Manp-α1→6Ins substructure, which has not previously been characterized unambigously, and may be acylated with a 2,3-dihydroxylignoceric fatty acid, a feature hitherto undescribed in fungal lipids.

  NMR, mass spectrometry, Sporothrix schenckii, glycoinositolphosphorylceramide

  Publication DOI: 10.1046/j.1432-1327.2001.02339.x
  Journal NLM ID: 0107600
  Publisher: Oxford, UK: Blackwell Science Ltd. on behalf of the Federation of European Biochemical Societies
  Correspondence: immglup@microbio.ufrj.br
  Institutions: Departamento de Biologia Celular e Genética and Departamento de Bioquímica, UERJ, Rio de Janeiro, Brasil, Kennedy Institute for Rheumatology, Imperial College, London, UK, Laboratory for Molecular Structure, NIBSC, Herts, UK, Instituto de Microbiologia, CCS-Bloco I, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brasil
  Methods: 13C NMR, 1H NMR, gel filtration, GC-MS, GLC, MALDI-MS, HPLC, TOCSY, methylation analysis, HMBC, HMQC, NOESY, ammonolysis
  
   
  
  Cryptococcus neoformans
  CSDB ID 40674 (all data & tools)

Show legend Show as text

Structure type: structural motif or average structure
Compound class: glucuronoxylomannan
Contained glycoepitopes: IEDB_114701,IEDB_115136,IEDB_115576,IEDB_130701,IEDB_1394182,IEDB_140116,IEDB_140630,IEDB_144983,IEDB_145668,IEDB_152206,IEDB_164174,IEDB_167188,IEDB_174332,IEDB_2270799,IEDB_423153,IEDB_76933,IEDB_983930,SB_197,SB_44,SB_67,SB_72

• Article ID: 6926
  Doering TL "A unique alpha-1,3 mannosyltransferase of the pathogenic fungus Cryptococcus neoformans" - Journal of Bacteriology 181 (1999) 5482-5488
  

  The major virulence factor of the pathogenic fungusCryptococcus neoformans is an extensive polysaccharide capsule which surrounds the cell. Almost 90% of the capsule is composed of a partially acetylated linear α-1,3-linked mannan substituted with D-xylose and D-glucuronic acid. A novel mannosyltransferase with specificity appropriate for a role in the synthesis of this glucuronoxylomannan is active in cryptococcal membranes. This membrane-associated activity transfers mannose in vitro from GDP-mannose to an α-1,3-dimannoside acceptor, forming a second α-1,3 linkage. Product formation by the transferase is dependent on protein, time, temperature, divalent cations, and each substrate. It is not affected by amphomycin or tunicamycin but is inhibited by GDP and mannose-1-phosphate. The described activity is not detectable in the model yeast Saccharomyces cerevisiae, consistent with the absence of a similar polysaccharide structure in that organism. A second mannosyltransferase from C. neoformans membranes adds mannose in α-1,2 linkage to the same dimannoside acceptor. The two activities differ in pH optimum and cation preference. While the α-1,2 transferase does not have specificity appropriate for a role in glucuronoxylomannan synthesis, it may participate in production of mannoprotein components of the capsule. This study suggests two new targets for antifungal drug discovery.

  Journal NLM ID: 2985120R
  WWW link: http://jb.asm.org/content/181/17/5482.long
  Publisher: American Society for Microbiology
  Correspondence: doering@borcim.wustl.edu
  Institutions: Department of Pharmacology, Cornell University Medical College, New York, New York
  Methods: enzymatic digestion, enzymatic assay, radiolabelling
  
   
  
  Cryptococcus neoformans B
  CSDB ID 40487 (all data & tools)

Show legend Show as text

Structure type: suggested polymer biological repeating unit
Contained glycoepitopes: IEDB_114701,IEDB_115136,IEDB_115576,IEDB_130701,IEDB_1394182,IEDB_140116,IEDB_140630,IEDB_144983,IEDB_145668,IEDB_152206,IEDB_164174,IEDB_167188,IEDB_174332,IEDB_2270799,IEDB_423153,IEDB_76933,IEDB_983930,SB_197,SB_44,SB_67,SB_72

• Article ID: 6961
  Bar-Peled M, Griffith CL, Doering TL "Functional cloning and characterization of a UDP-glucuronic acid decarboxylase: the pathogenic fungus Cryptococcus neoformans elucidates UDP-xylose synthesis" - Proceedings of the National Academy of Sciences of the USA 21 (2001) 12003-12008
  

  UDP-xylose is a sugar donor required for the synthesis of diverse and important glycan structures in animals, plants, fungi, and bacteria. Xylose-containing glycans are particularly abundant in plants and in the polysaccharide capsule that is the major virulence factor of the pathogenic fungus Cryptococcus neoformans. Biosynthesis of UDP-xylose is mediated by UDP-glucuronic acid decarboxylase, which converts UDP-glucuronic acid to UDP-xylose. Although this enzymatic activity was described over 40 years ago it has never been fully purified, and the gene encoding it has not been identified. We used homology to a bacterial gene, hypothesized to encode a related function, to identify a cryptococcal sequence as putatively encoding a UDP-glucuronic acid decarboxylase. A soluble 47-kDa protein derived from bacteria expressing the C. neoformans gene catalyzed conversion of UDP-glucuronic acid to UDP-xylose, as confirmed by NMR analysis. NADH, UDP, and UDP-xylose inhibit the activity. Close homologs of the cryptococcal gene, which we termed UXS1, appear in genome sequence data from organisms ranging from bacteria to humans.

  Publication DOI: 10.1073/pnas.211229198
  Journal NLM ID: 7505876
  Publisher: National Academy of Sciences
  Correspondence: peled@ccrc.uga.edu
  Institutions: Complex Carbohydrate Research Center and Department of Botany, University of Georgia, Athens, GA 30602, USA, Department of Molecular Microbiology, Washington University School of Medicine, St. Louis, MO 63110, USA
  Methods: 1H NMR, SDS-PAGE, HPLC, cloning, protein expression, UDP-GlcA decarboxylase assay
  
   
  
  Cryptococcus neoformans B
  CSDB ID 40538 (all data & tools)

Show legend Show as text

Structure type: polymer chemical repeating unit
Contained glycoepitopes: IEDB_114701,IEDB_130701,IEDB_134624,IEDB_136044,IEDB_136095,IEDB_136906,IEDB_137472,IEDB_1394182,IEDB_141794,IEDB_144983,IEDB_145668,IEDB_151528,IEDB_152206,IEDB_164174,IEDB_167188,IEDB_174332,IEDB_190606,IEDB_983930,SB_163,SB_165,SB_166,SB_187,SB_195,SB_197,SB_44,SB_67,SB_7,SB_72,SB_88

• Article ID: 6961
  Bar-Peled M, Griffith CL, Doering TL "Functional cloning and characterization of a UDP-glucuronic acid decarboxylase: the pathogenic fungus Cryptococcus neoformans elucidates UDP-xylose synthesis" - Proceedings of the National Academy of Sciences of the USA 21 (2001) 12003-12008
  

  UDP-xylose is a sugar donor required for the synthesis of diverse and important glycan structures in animals, plants, fungi, and bacteria. Xylose-containing glycans are particularly abundant in plants and in the polysaccharide capsule that is the major virulence factor of the pathogenic fungus Cryptococcus neoformans. Biosynthesis of UDP-xylose is mediated by UDP-glucuronic acid decarboxylase, which converts UDP-glucuronic acid to UDP-xylose. Although this enzymatic activity was described over 40 years ago it has never been fully purified, and the gene encoding it has not been identified. We used homology to a bacterial gene, hypothesized to encode a related function, to identify a cryptococcal sequence as putatively encoding a UDP-glucuronic acid decarboxylase. A soluble 47-kDa protein derived from bacteria expressing the C. neoformans gene catalyzed conversion of UDP-glucuronic acid to UDP-xylose, as confirmed by NMR analysis. NADH, UDP, and UDP-xylose inhibit the activity. Close homologs of the cryptococcal gene, which we termed UXS1, appear in genome sequence data from organisms ranging from bacteria to humans.

  Publication DOI: 10.1073/pnas.211229198
  Journal NLM ID: 7505876
  Publisher: National Academy of Sciences
  Correspondence: peled@ccrc.uga.edu
  Institutions: Complex Carbohydrate Research Center and Department of Botany, University of Georgia, Athens, GA 30602, USA, Department of Molecular Microbiology, Washington University School of Medicine, St. Louis, MO 63110, USA
  Methods: 1H NMR, SDS-PAGE, HPLC, cloning, protein expression, UDP-GlcA decarboxylase assay
  
   
  
  Cryptococcus neoformans
  CSDB ID 40794 (all data & tools)

Show legend Show as text

Structure type: structural motif or average structure ; 308000
Trivial name: xylomannan
Contained glycoepitopes: IEDB_114701,IEDB_115576,IEDB_130701,IEDB_1394182,IEDB_140116,IEDB_144983,IEDB_152206,IEDB_164174,IEDB_167188,IEDB_174332,IEDB_76933,IEDB_983930,SB_197,SB_44,SB_67,SB_72

• Article ID: 7112
  Smiderle FR, Carbonero ER, Mellinger CG, Sassaki GL, Gorin PA, Iacomini M. "Structural characterization of a polysaccharide and a β-glucan isolated from the edible mushroom Flammulina velutipes" - Phytochemistry 67(19) (2006) 2189-2196
  

  Two polysaccharides were isolated from the basidiomycete Flammulina velutipes, via successive hot extraction with water, 2% and 25% aq. KOH, and then submitted to freeze-drying. The precipitate formed by repeated freeze-thawing from the 2% aq. KOH extraction PK2 was analyzed by determination of its monosaccharide composition, as well as by methylation analyses using GC-MS, mono- ((13)C, (1)H NMR) and bidimensional ((1)H (obs.), (13)C HMQC) spectroscopy, and controlled Smith degradations. It was established to be a branched β-glucan, with a main chain of (1→3)-linked-Glcp residues, substituted at O-6 by single-unit β-Glcp side chains. The precipitate formed by repeated freeze-thawing from the 25% KOH extraction PK25 contained Xyl, Man, and Glc and was heterogeneous by HSPEC and extraction with DMSO gave a soluble xylomannan (XM). It was homogeneous with a molar mass 308000 g/mol (dn/dc=0.186). Using the above chemical analyses, it was a xylomannan with Man and Xyl in a 3:2 molar ratio. Its main chain consisted of (1→3)-linked α-Manp units, mainly substituted at O-4 by β-Xylp units or with some β-Xylp-(1→3)-β-Xylp groups.

  Flammulina velutipes, Basidiomycete, Branched β-glucan, Xylomannan

  NCBI PubMed ID: 16884744
  Publication DOI: 10.1016/j.phytochem.2006.06.022
  Journal NLM ID: 0151434
  Publisher: Elsevier
  Correspondence: Iacomini Marcello
  Institutions: Departamento de Bioquímica e Biologia Molecular, Universidade Federal do Paraná, Curitiba, PR, Brazil
  Methods: 13C NMR, 1H NMR, methylation, NMR-2D, GC-MS, acid hydrolysis, Smith degradation, composition analysis, HPLC, HPSEC-MALLS, extraction, reduction
  
   
  
  Flammulina velutipes
  CSDB ID 41990 (all data & tools)

Show legend Show as text

Structure type: polymer chemical repeating unit
Compound class: CPS, glucuronoxylomannan (GXM)
Contained glycoepitopes: IEDB_114701,IEDB_115136,IEDB_115576,IEDB_130701,IEDB_1394182,IEDB_140116,IEDB_140630,IEDB_144983,IEDB_145668,IEDB_152206,IEDB_164174,IEDB_167188,IEDB_174332,IEDB_423153,IEDB_76933,IEDB_983930,SB_197,SB_44,SB_67,SB_72

• Article ID: 7125
  McFadden DC, Fries BC, Wang F, Casadevall A "Capsule structural heterogeneity and antigenic variation in Cryptococcus neoformans" - Eukaryotic Cell 6(8) (2007) 1464-1473
  

  Cryptococcus neoformans is a human pathogenic fungus with a capsule composed primarily of glucuronoxylomannan (GXM) that is important for virulence. Current views of GXM structure postulate a polymer composed of repeating mannose trisaccharide motifs bearing a single β(1,2) glucuronic acid with variable xylose and O-acetyl substitutions to form six triads. GXM from different strains is notoriously variable in triad composition, but it is not known if the polymer consists of one or more motif-repeating units. We investigated the polymeric organization of GXM by using mass spectrometry to determine if its compositional motif arrangement was similar to that of bacterial capsular polysaccharides, namely, a polymer of a single repeating unit. The results were consistent with, and confirmatory for, the current view that the basic unit of GXM is a repeating mannose trisaccharide motif, but we also found evidence for the copolymerization of different GXM repeating units in one polysaccharide molecule. Analysis of GXM from isogenic phenotypic switch variants suggested structural differences caused by glucuronic acid positional effects, which implied flexibility in the synthetic pathway. Our results suggest that cryptococcal capsule synthesis is fundamentally different from that observed in prokaryotes and employs a unique eukaryotic approach, which theoretically could synthesize an infinite number of structural combinations. The biological significance of this capsule construction scheme is that it is likely to confer a powerful avoidance strategy for interactions with the immune system and phagocytic environmental predators. Consistent with this premise, the antigenic variation of a capsular epitope recognized by a nonprotective antibody was observed under different growth conditions.

  biosynthesis, antibodies, infection, polysaccharide capsule, Glucuronoxylomannan

  Publication DOI: 10.1128/EC.00162-07
  Journal NLM ID: 101130731
  Publisher: American Society for Microbiology
  Correspondence: Arturo Casadevall
  Institutions: Department of Medicine, Division of Infectious Disease, Department of Microbiology and Immunology, Laboratory for Macromolecular Analysis and Proteomics, Albert Einstein College of Medicine, Bronx, New York 10461
  Methods: 1H NMR, partial acid hydrolysis, TLC, ESI-MS, acid hydrolysis, MS/MS, electrophoresis, HPLC, light scattering, viscosity measurement
  
   
  
  Cryptococcus neoformans D
  CSDB ID 41797 (all data & tools)

Show legend Show as text

Structure type: polymer chemical repeating unit
Compound class: CPS, EPS, glucuronoxylomannan (GXM)
Contained glycoepitopes: IEDB_114701,IEDB_115136,IEDB_115576,IEDB_130701,IEDB_1394182,IEDB_140116,IEDB_140630,IEDB_144983,IEDB_145668,IEDB_152206,IEDB_164174,IEDB_167188,IEDB_174332,IEDB_2270799,IEDB_423153,IEDB_76933,IEDB_983930,SB_197,SB_44,SB_67,SB_72

• Article ID: 7125
  McFadden DC, Fries BC, Wang F, Casadevall A "Capsule structural heterogeneity and antigenic variation in Cryptococcus neoformans" - Eukaryotic Cell 6(8) (2007) 1464-1473
  

  Cryptococcus neoformans is a human pathogenic fungus with a capsule composed primarily of glucuronoxylomannan (GXM) that is important for virulence. Current views of GXM structure postulate a polymer composed of repeating mannose trisaccharide motifs bearing a single β(1,2) glucuronic acid with variable xylose and O-acetyl substitutions to form six triads. GXM from different strains is notoriously variable in triad composition, but it is not known if the polymer consists of one or more motif-repeating units. We investigated the polymeric organization of GXM by using mass spectrometry to determine if its compositional motif arrangement was similar to that of bacterial capsular polysaccharides, namely, a polymer of a single repeating unit. The results were consistent with, and confirmatory for, the current view that the basic unit of GXM is a repeating mannose trisaccharide motif, but we also found evidence for the copolymerization of different GXM repeating units in one polysaccharide molecule. Analysis of GXM from isogenic phenotypic switch variants suggested structural differences caused by glucuronic acid positional effects, which implied flexibility in the synthetic pathway. Our results suggest that cryptococcal capsule synthesis is fundamentally different from that observed in prokaryotes and employs a unique eukaryotic approach, which theoretically could synthesize an infinite number of structural combinations. The biological significance of this capsule construction scheme is that it is likely to confer a powerful avoidance strategy for interactions with the immune system and phagocytic environmental predators. Consistent with this premise, the antigenic variation of a capsular epitope recognized by a nonprotective antibody was observed under different growth conditions.

  biosynthesis, antibodies, infection, polysaccharide capsule, Glucuronoxylomannan

  Publication DOI: 10.1128/EC.00162-07
  Journal NLM ID: 101130731
  Publisher: American Society for Microbiology
  Correspondence: Arturo Casadevall
  Institutions: Department of Medicine, Division of Infectious Disease, Department of Microbiology and Immunology, Laboratory for Macromolecular Analysis and Proteomics, Albert Einstein College of Medicine, Bronx, New York 10461
  Methods: 1H NMR, partial acid hydrolysis, TLC, ESI-MS, acid hydrolysis, MS/MS, electrophoresis, HPLC, light scattering, viscosity measurement
  
   
  
  Cryptococcus neoformans A
  CSDB ID 42199 (all data & tools)
• Article ID: 7136
  Liu OW, Kelly MJ, Chow ED, Madhani HD "Parallel beta-helix proteins required for accurate capsule polysaccharide synthesis and virulence in the yeast Cryptococcus neoformans" - Eukaryotic Cell 6(4) (2007) 630-640
  

  The principal capsular polysaccharide of the opportunistic fungal pathogen Cryptococcus neoformans consists of an α-1,3-linked mannose backbone decorated with a repeating pattern of glucuronyl and xylosyl side groups. This structure is critical for virulence, yet little is known about how the polymer, called glucuronoxylomannan (GXM), is faithfully synthesized and assembled. We have generated deletions in two genes encoding predicted parallel β-helix repeat proteins, which we have designated PBX1 and PBX2. Deletion of either gene results in a dry-colony morphology, clumpy cells, and decreased capsule integrity. Two-dimensional nuclear magnetic resonance spectroscopy of purified GXM from the mutants indicated that both the wild-type GXM structure and novel, aberrant linkages were present. Carbohydrate composition and linkage analysis determined that these aberrant structures are correlated with the incorporation of terminal glucose residues that are not found in wild-type capsule polysaccharide. We conclude that Pbx1 and Pbx2 are required for the fidelity of GXM synthesis and may be involved in editing incorrectly added glucose residues. PBX1 and PBX2 knockout mutants showed severely attenuated virulence in a murine inhalation model of cryptococcosis. Unlike acapsular strains, these mutant strains induced delayed symptoms of cryptococcosis, though the infected animals eventually contained the infection and recovered.

  gene, UDP-Glucose dehydrogenase, Cryptococcus neoformans, glucuronoxylomannan (GXM)

  NCBI PubMed ID: 17337638
  Publication DOI: 10.1128/EC.00398-06
  Journal NLM ID: 101130731
  Publisher: American Society for Microbiology
  Correspondence: Madhani HD
  Institutions: Department of Biochemistry and Biophysics and Department of Pharmaceutical Chemistry, University of California, San Francisco, California, USA
  Methods: 13C NMR, 1H NMR, NMR-2D, virulence assays, PCR, GLC-EI-MS, acid hydrolysis, composition analysis, genetic methods, HPAEC-PAD, microscopy
  
   
  
  Cryptococcus neoformans A H99
  CSDB ID 41809 (all data & tools)

Show legend Show as text

Structure type: suggested polymer biological repeating unit
Compound class: CPS, glucuronoxylomannan (GXM)
Contained glycoepitopes: IEDB_114701,IEDB_115136,IEDB_115576,IEDB_130701,IEDB_1394182,IEDB_140116,IEDB_140630,IEDB_144983,IEDB_145668,IEDB_152206,IEDB_164174,IEDB_167188,IEDB_174332,IEDB_2270799,IEDB_423153,IEDB_76933,IEDB_983930,SB_197,SB_44,SB_67,SB_72

• Article ID: 7125
  McFadden DC, Fries BC, Wang F, Casadevall A "Capsule structural heterogeneity and antigenic variation in Cryptococcus neoformans" - Eukaryotic Cell 6(8) (2007) 1464-1473
  

  Cryptococcus neoformans is a human pathogenic fungus with a capsule composed primarily of glucuronoxylomannan (GXM) that is important for virulence. Current views of GXM structure postulate a polymer composed of repeating mannose trisaccharide motifs bearing a single β(1,2) glucuronic acid with variable xylose and O-acetyl substitutions to form six triads. GXM from different strains is notoriously variable in triad composition, but it is not known if the polymer consists of one or more motif-repeating units. We investigated the polymeric organization of GXM by using mass spectrometry to determine if its compositional motif arrangement was similar to that of bacterial capsular polysaccharides, namely, a polymer of a single repeating unit. The results were consistent with, and confirmatory for, the current view that the basic unit of GXM is a repeating mannose trisaccharide motif, but we also found evidence for the copolymerization of different GXM repeating units in one polysaccharide molecule. Analysis of GXM from isogenic phenotypic switch variants suggested structural differences caused by glucuronic acid positional effects, which implied flexibility in the synthetic pathway. Our results suggest that cryptococcal capsule synthesis is fundamentally different from that observed in prokaryotes and employs a unique eukaryotic approach, which theoretically could synthesize an infinite number of structural combinations. The biological significance of this capsule construction scheme is that it is likely to confer a powerful avoidance strategy for interactions with the immune system and phagocytic environmental predators. Consistent with this premise, the antigenic variation of a capsular epitope recognized by a nonprotective antibody was observed under different growth conditions.

  biosynthesis, antibodies, infection, polysaccharide capsule, Glucuronoxylomannan

  Publication DOI: 10.1128/EC.00162-07
  Journal NLM ID: 101130731
  Publisher: American Society for Microbiology
  Correspondence: Arturo Casadevall
  Institutions: Department of Medicine, Division of Infectious Disease, Department of Microbiology and Immunology, Laboratory for Macromolecular Analysis and Proteomics, Albert Einstein College of Medicine, Bronx, New York 10461
  Methods: 1H NMR, partial acid hydrolysis, TLC, ESI-MS, acid hydrolysis, MS/MS, electrophoresis, HPLC, light scattering, viscosity measurement
  
   
  
  Cryptococcus neoformans B
  CSDB ID 42200 (all data & tools)