Glycans from Streptococcal Cell Walls

The cell wall of Streptococcus faecalis, strain N, has been found to contain two antigenic glycans, a diheteroglycan of glucose and galactose and a tetraheteroglycan of rhamnose, glucose, galactose, and N-acetylgalactosamine. The present report describes the isolation, purification, and structural and immunochemical characterization of the hitherto unknown diheteroglycan. A tentative structure has been proposed for the new glycan on the basis of structural information on oligosaccharides isolated from acid hydrolysates of the polymer and on the basis of immunological inhibition studies. Of considerable interest is the finding that, of the two major disaccharide moieties (lactosyl and gentiobiosyl) in the glycan, the lactosyl moiety is the immunodominant group.