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Structure type: oligomer
Compound class: mannan, disaccharide
Contained glycoepitopes: IEDB_130701,IEDB_137485,IEDB_144983,IEDB_144995,IEDB_152206,IEDB_164479,IEDB_983930,SB_44,SB_67,SB_72

• Article ID: 7323
  Shibata N, Okawa Y "Conformational analysis of β-1,2-linked mannobiose to mannoheptaose, specific antigen of pathogenic yeast Candida albicans" - Chemical and Pharmaceutical Bulletin 58(10) (2010) 1386-1390
  

  Candida albicans contains characteristic β-1,2-linked oligomannosyl moieties in the cell wall mannan. Reduction of the reducing termini of these oligosaccharides by NaBH 4 causes a significant downfield shift in the NMR signals for the second and third mannose units and upfield shift of the fourth mannose unit. To show the correlation between the shift in the NMR signals and the conformations of the β-1,2-linked mannooligosaccharides, we performed molecular mechanics calculations. Six energy minima of the β-1,2-linked mannobiose were found in the relaxed map computed using the AMBER force field. Five of the six energy minima could also be generated by a simulated annealing from a 900 K molecular dynamics. Similarly, the solution conformation of the β-1,2-linked mannotriose to mannoheptaose was identified by the high temperature-simulated annealing. In the mannotetraose, the nonreducing terminal mannose unit was located near the reducing terminal one and formed a folded conformation. This result suggests that a mannose unit affects the H-1 chemical shifts of not only the second mannose unit, but also the third and fourth mannose units.

  conformation, oligosaccharide, mannan, Candida albicans, high-temperature molecular dynamics

  NCBI PubMed ID: 20930409
  Publication DOI: 10.1248/cpb.58.1386
  Journal NLM ID: 0377775
  Publisher: Pharmaceutical Society Of Japan
  Correspondence: nshibata@tohoku-pharm.ac.jp
  Institutions: Department of Infection and Host Defense, Tohoku Pharmaceutical University, Sendai, Japan
  Methods: conformation analysis, GPC, hydrolysis
  
   
  
  Candida albicans NIH B-792
  CSDB ID 44093 (all data & tools)
• Article ID: 7666
  Takahashi S, Kudoh A, Okawa Y, Shibata N "Significant differences in the cell-wall mannans from three Candida glabrata strains correlate with antifungal drug sensitivity" - FEBS Journal 279(10) (2012) 1844-1856
  

  Candida glabrata is often the second or third most common cause of candidiasis after Candida albicans. C. glabrata infections are difficult to treat, often resistant to many azole antifungal agents and are associated with a high mortality rate in compromised patients. We determined the antigenic structure of the cell-wall mannoproteins from three C. glabrata strains, NBRC 0005, NBRC 0622 and NBRC 103857. 1H NMR and methylation analyses of the acetolysis products of these mannoproteins showed a significant difference in the amount of the β-1,2-linked mannose residue and side-chain structure. The C. glabrata NBRC 103857 strain contained up to the triose side chains and the nonreducing terminal of the triose was predominantly the β-1,2-linked mannose residue. By contrast, the mannans of the two former strains possessed up to the tetraose side chains and the amount of the β-1,2-linked mannose residue was very low. Larger oligosaccharides than tetraose in the acetolysis products of these mannans were identified as incomplete cleavage fragments by analyzing methylation, 1H NMR spectra and the α1-2,3 mannosidase degradation reaction. Resistance to the antifungal drugs itraconazole and micafungin was significantly different in these strains. Interestingly, the NBRC 103857 strain, which involved a large amount of the β-1,2-linked mannose residues, exhibited significant sensitivity to these antifungal drugs.

  oligosaccharide, polysaccharide, NMR spectroscopy, azole resistance, cell-wall mannan

  NCBI PubMed ID: 22404982
  Publication DOI: 10.1111/j.1742-4658.2012.08564.x
  Journal NLM ID: 101229646
  Publisher: Blackwell Publishing
  Correspondence: nshibata@tohoku-pharm.ac.jp
  Institutions: Department of Infection and Host Defense, Tohoku Pharmaceutical University, Sendai, Japan
  Methods: 1H NMR, methylation, GC-MS, acid hydrolysis, biological assays, enzymatic digestion, extraction, acetylation, acetolysis, reduction, cell growth, DQF-COSY
  
   
  
  Candida glabrata NBRC 0622
  CSDB ID 45855 (all data & tools)