Structural study of phosphomannan of yeast-form cells of Candida albicans J-1012 strain with special reference to application of mild acetolysis.
Structural analysis of the phosphomannan isolated from yeast-form cells of a pathogenic yeast, Candida albicans J-1012 strain, was conducted. Treatment of this phosphomannan (Fr. J) with 10 mM HCl at 100 degrees C for 60 min gave a mixture of beta-1,2-linked manno-oligosaccharides, from tetraose to biose plus mannose, and an acid-stable mannan moiety (Fr. J-a), which was then acetolyzed by means of an acetolysis medium, 100:100:1 (v/v) mixture of (CH3CO)2O, CH3COOH, and H2SO4, at 40 degrees C for 36 h in order to avoid cleavage of the beta-1,2 linkage. The resultant manno-oligosaccharide mixture was fractionated on a column of Bio-Gel P-2 to yield insufficiently resolved manno-oligosaccharide fractions higher than pentaose and lower manno-oligosaccharides ranging from tetraose to biose plus mannose. The higher manno-oligosaccharide fraction was then digested with the Arthrobacter GJM-1 alpha-mannosidase in order to cleave the enzyme-susceptible alpha-1,2 and alpha-1,3 linkages, leaving manno-oligosaccharides containing the beta-1,2 linkage at their nonreducing terminal sites, Manp beta 1----2Manp alpha 1----2Manp alpha 1----2Manp alpha 1----2Man, Manp beta 1----2Manp beta 1----2Manp alpha 1----2Manp alpha 1---- 2Manp alpha 1----2Man, and Manp beta 1----2Manp beta 1----2Manp beta 1----2Manp alpha 1---- 2Manp alpha 1----2Manp alpha 1----2Man. However, the result of acetolysis of Fr. J-a by means of a 10:10:1 (v/v) mixture of (CH3CO)2O, CH3COOH, and H2SO4 at 40 degrees C for 13 h was significantly different from that obtained by the mild acetolysis method; i.e., the amount of mannose was apparently larger than that formed by the mild acetolysis method. In summary, a chemical structure for Fr. J as a highly branched mannan containing 14 different branching moieties was proposed.
Kobayashi
H
H
Second Department of Hygienic Chemistry, Tohoku College of Pharmacy, Miyagi, Japan.
Shibata
N
N
Mitobe
H
H
Ohkubo
Y
Y
Suzuki
S
S
D000089:Acetic Anhydrides; D002176:Candida albicans / Q000032:analysis*; D002240:Carbohydrate Sequence; D006851:Hydrochloric Acid; D009682:Magnetic Resonance Spectroscopy; D008351:Mannans / Q000032:analysis*; D008361:Mannosidases / Q000378:metabolism; D008745:Methylation; D008969:Molecular Sequence Data; D015394:Molecular Structure; D009844:Oligosaccharides / Q000032:analysis
D000089:Acetic Anhydrides; D008351:Mannans; D009844:Oligosaccharides; C031800:acetic anhydride; C005437:phosphomannan; D008361:Mannosidases; D006851:Hydrochloric Acid