FIG. 1.

Structures of C. albicans mannan (M, d-mannopyranose units; GlcNAc, N-acetylglucosamine units; Asn, asparagine residue). (A) Representative structure of serotype A strain mannan. Side chains shown by the outlined letter M indicate putative serotype A-specific structures containing β-1,2-linked mannopyranosyl residues at the nonreducing terminal (i.e., antigenic factor 6); other side chains depicted are common in mannans from both serotypes. Reprinted from reference 267 with permission of the publisher. (B) Representative structure of serotype B strain mannan. Single mannose units linked by α-1,6 bonds to the oligosaccharide branches containing α-1,2- and α-1,3-linked mannopyranosyl residues make a serotype B-specific epitope (i.e., antigenic factor 4); α-1,6-linked mannose residues in brackets indicate the partial absence of these units in mannan from C. albicans B cells. Reprinted from reference 271 with permission. Structures corresponding to other antigenic factors present in mannans from both C. albicans serotypes are described in the text.