Structural studies of mannans from Candida albicans (serotypes A and B), Candida parapsilosis, Candida stellatoidea, and Candida tropicalis

Abstract

Mannans have been isolated from cells of the following Candida species: C. albicans (serotype A), C. albicans (serotype B), C. parapsilosis, C. stellatoidea, and C. tropicalis. Methylation and hydrolysis of each mannan yielded the following methyl ethers of d-mannose (with only small variations in the relative amounts): 2,3,4,6-tetra-O-methyl-d-mannose, 3,4,6-tri-O-methyl-d-mannose (major), 2,3,4-tri-O-methyl-d-mannose (minor), 2,4,6-tri-O-methyl-d-mannose (minor), 3,4-di-O-methyl-d-mannose, and 3,5-di-O-methyl-d-mannose. The mannans therefore contained a predominance of 1 → 2 linkages in the linear portions, with smaller amounts of 1 → 6 and 1 → 3 linkages. Branching occurred through C-2 and C-6 of d-mannopyranose and d-mannofuranose units, and branches were terminated by d-mannopyranose units. The specific rotations of the mannans indicated that most of the glycosidic linkages were in the α configuration. The structural studies support the observation that the mannans are very similar serologically and show cross-reactivity in antisera to any of the parent organisms.