Structural study of cell wall phosphomannan of Candida albicans NIH B-792 (serotype B) strain, with special reference to 1H and 13C NMR analyses of acid-labile oligomannosyl residues.
Chemical structures of manno-oligosaccharides, from biose to heptaose, released from the phosphomannan of Candida albicans NIH B-792 strain (serotype B) by mild acid hydrolysis were investigated. The results of 1H NMR, 13C NMR, and fast atom bombardment mass spectrometry analyses confirmed that these manno-oligosaccharides belong to a homologous beta-1,2-linked series. Although chemical shifts of 1H NMR patterns of these oligosaccharides were considerably too complicated to be assigned, their 13C NMR patterns were sufficiently simple to be interpreted, exhibiting a regular increase of downfield shift of ppm values of the C-1 atom from each mannopyranose residue in proportion to their molecular weights. In order to determine the whole chemical structure of the parent phosphomannan, the acid-stable domain was subjected to acetolysis and then enzymolysis with the Arthrobacter GJM-1 alpha-mannosidase and the resultant manno-oligosaccharides were investigated for their chemical structures by 1H NMR spectroscopy. The results of a precipitin-inhibition test using the beta-1,2-linked manno-oligosaccharides, from biose to hexaose, in comparison with the corresponding isomers containing alpha-1,2 linkage with small amounts of alpha-1,3 linkage, indicated that the haptens possessing the former linkage exhibited much higher inhibitory effects than the corresponding isomers containing the latter linkages did. Based on the present findings, a chemical structure of the phosphomannan of this C. albicans strain was proposed.
Kobayashi
H
H
Second Department of Hygienic Chemistry, Tohoku College of Pharmacy, Miyagi, Japan.
Shibata
N
N
Nakada
M
M
Chaki
S
S
Mizugami
K
K
Ohkubo
Y
Y
Suzuki
S
S
D001173:Arthrobacter / Q000201:enzymology; D002176:Candida albicans / Q000032:analysis*; D002236:Carbohydrate Conformation; D002240:Carbohydrate Sequence; D002247:Carbon Isotopes; D002473:Cell Wall / Q000032:analysis; D006859:Hydrogen; D006868:Hydrolysis; D009682:Magnetic Resonance Spectroscopy / Q000379:methods; D008351:Mannans / Q000302:isolation & purification; D008361:Mannosidases; D013058:Mass Spectrometry; D008745:Methylation; D008969:Molecular Sequence Data; D043323:alpha-Mannosidase
D002247:Carbon Isotopes; D008351:Mannans; D006859:Hydrogen; C005437:phosphomannan; D008361:Mannosidases; D043323:alpha-Mannosidase