Differences in the acid-labile component of Candida albicans mannan from hydrophobic and hydrophilic yeast cells

Cell surface hydrophobicity of the opportunistic fungal pathogen Candida albicans has been linked to the level of cell wall protein glycosylation, Previous work demonstrated that outer chain mannosylation, rather than overall glycosylation, correlated with cell surface hydrophobicity. These studies further suggested that the phosphodiester-linked, acid-labile beta-1,2-mannan was the correlating element. The present work tests this hypothesis and extends the previous results. The composition of bulk mannan from hydrophobic and hydrophilic yeast cells, and the acid-labile mannan from both cell types are compared. Compositional analysis shows that the protein, hexose, and phosphorus content of bulk mannan is similar between the two phenotypes. Electrophoretic separation of acid-released and fluorophore-labeled mannan shows that the acid-labile oligomannosides from hydrophobic cells are longer and potentially in greater abundance than those from hydrophilic cells. These results suggest that regulation of a single step in cell wall protein outer chain mannosylation affects the cell surface ultrastructure and phenotype of C. albicans.