Structural study of a cell wall mannan-protein complex of the pathogenic yeast Candida glabrata IFO 0622 strain.
We conducted a structural analysis of the cell wall mannan-protein complex (mannan) isolated from a pathogenic yeast, Candida glabrata IFO 0622 strain. The chemical structure of mannobiose released from this mannan by treatment with 10 mM HCl at 100 degrees C for 1 h was identified as Manp beta 1-2Man. The treatment of this mannan with 100 mM NaOH at 25 degrees C for 18 h gave a mixture of alpha-1,2- and alpha-1,3-linked oligosaccharides, from tetraose to biose, and mannose. The acid- and alkali-stable mannan moiety was subjected to mild acetolysis with a 100:100:1 (v/v) mixture of (CH3CO)2O, CH3COOH, and H2SO4 at 40 degrees C for 36 h. The resultant three novel oligosaccharides, tetraose, hexaose, and heptaose, were identified as Manp beta 1-2Manp alpha 1-2Manp alpha 1-2Man, Manp alpha 1-2Manp alpha 1-2Manp alpha 1-6Manp alpha 1-2Manp alpha 1-2Man, and Manp alpha 1-3Manp alpha 1-2Manp alpha 1-2Manp alpha 1-6Manp alpha 1- 2Manp alpha 1-2Man, respectively, in addition to the three known oligosaccharides, Manp alpha 1-2Man, Manp alpha 1-2Manp alpha 1-2Man, and Manp alpha 1-3Manp alpha 1-2Manp alpha 1-2Man. A sequential analytical procedure involving partial acid hydrolysis with hot 0.3 M H2SO4, methylation, fast atom bombardment mass, and 1H NMR analyses was quite effective in the structural determination of the novel oligosaccharides. The results indicate that this mannan possesses a structure closely resembling that of Saccharomyces cerevisiae X2180-1A wild type strain, with the presence of small amounts of oligomannosyl residue, Manp beta 1-2Manp alpha 1-X, corresponding to one of the epitopes dominating serotype-A specificity of Candida spp., in addition to branches corresponding to hexaose and heptaose each containing one intermediary alpha-1,6 linkage.
Kobayashi
H
H
Second Department of Hygienic Chemistry, Tohoku College of Pharmacy, Miyagi, Japan.
Mitobe
H
H
Takahashi
K
K
Yamamoto
T
T
Shibata
N
N
Suzuki
S
S
D002175:Candida / Q000737:chemistry*; D002240:Carbohydrate Sequence; D002473:Cell Wall / Q000737:chemistry; D002850:Chromatography, Gel; D005656:Fungal Proteins / Q000737:chemistry* / Q000302:isolation & purification; D007202:Indicators and Reagents; D009682:Magnetic Resonance Spectroscopy; D008351:Mannans / Q000737:chemistry* / Q000302:isolation & purification; D008565:Membrane Proteins / Q000737:chemistry* / Q000302:isolation & purification; D008969:Molecular Sequence Data; D009844:Oligosaccharides / Q000737:chemistry / Q000302:isolation & purification; D012441:Saccharomyces cerevisiae / Q000737:chemistry; D016339:Spectrometry, Mass, Fast Atom Bombardment
D005656:Fungal Proteins; D007202:Indicators and Reagents; D008351:Mannans; D008565:Membrane Proteins; D009844:Oligosaccharides