Chemical structure of the cell-wall mannan of Candida albicans serotype A and its difference in yeast and hyphal forms.
The structure of the cell-wall mannan from the J-1012 (serotype A) strain of the polymorphic yeast Candida albicans was determined by acetolysis under mild conditions followed by HPLC and sequential NMR experiments. The serotype A mannan contained beta-1,2-linked mannose residues attached to alpha-1,3-linked mannose residues and alpha-1,6-linked branching mannose residues. Using a beta-1,2-mannosyltransferase, we synthesized a three-beta-1,2-linkage-containing mannoheptaose and used it as a reference oligosaccharide for 1H-NMR assignment. On the basis of the results obtained, we derived an additivity rule for the 1H-NMR chemical shifts of the beta-1,2-linked mannose residues. The morphological transformation of Candida cells from the yeast form to the hyphal form induced a significant decrease in the phosphodiesterified acid-labile beta-1,2-linked manno-oligosaccharides, whereas the amount of acid-stable beta-1,2 linkage-containing side chains did not change. These results suggest that the Candida mannan in candidiasis patients contains beta-1,2-linked mannose residues and that they behave as a target of the immune system.
Shibata
Nobuyuki
N
Department of Infection and Host Defense, Tohoku Pharmaceutical University, Sendai, Miyagi 981-8558, Japan. nshibata@tohoku-pharm.ac.jp
Suzuki
Akifumi
A
Kobayashi
Hidemitsu
H
Okawa
Yoshio
Y
D002176:Candida albicans / Q000737:chemistry* / Q000166:cytology* / Q000378:metabolism; D002236:Carbohydrate Conformation; D002240:Carbohydrate Sequence; D002473:Cell Wall / Q000737:chemistry*; D025301:Hyphae / Q000737:chemistry* / Q000648:ultrastructure; D008351:Mannans / Q000737:chemistry* / Q000378:metabolism; D008358:Mannose / Q000737:chemistry / Q000378:metabolism; D008364:Mannosyltransferases / Q000378:metabolism; D008969:Molecular Sequence Data; D019906:Nuclear Magnetic Resonance, Biomolecular; D009844:Oligosaccharides / Q000737:chemistry; D012703:Serotyping
D008351:Mannans; D009844:Oligosaccharides; D008364:Mannosyltransferases; D008358:Mannose