GLYCANS FROM STREPTOCOCCAL CELL-WALLS - MOLECULAR-STRUCTURE AND IMMUNOLOGICAL PROPERTIES OF AN ANTIGENIC GLYCAN FROM STREPTOCOCCUS-BOVIS

The molecular structure and immunological properties of an antigenic glycan from the cell wall of S. bovis, strain C3, a member of the Group D streptococci, were determined by methylation analysis, periodate oxidation and hapten inhibition. The glycan is a tetraheteroglycan composed of 6-deoxy-L-talose, L-rhamnose, D-galactose and D-glucuronic acid. The sugar sequence and the types of glycosidic linkages of the glycan are a main chain of L-rhamnosyl-(1,3)-D-galactosyl-(1,2)-L-rhamnosyl-(1,3)-6-deoxy-L-talosyl(1,3)- units with D-glucuronosyl residues attached to position 4 of the 1st rhamnose of each repeating unit of the main chain. The D-glucuronic acid moiety is the primary immunodeterminant group of the glycan. On the basis of hapten inhibition data, it was concluded that the binding of the antigen to the antibody occurs at the hydroxyl groups at positions 2 and 3 and the carboxyl group at position 6 of the D-glucuronic acid moieties. The antigen was used to prepare [rabbit] antiserum with anti-glucuronic acid antibodies [for vaccines].