Structural studies of Escherichia coli O127 O-antigen polysaccharide

The O-specific side-chain of the lipopolysaccharide from Escherichia coli O127a;4932-53) has been investigated using 2D NMR spectroscopy, methylation analysis, and partial solvolysis with anhydrous hydrogen flouride as the principal methods. It is concluded that the polysaccharide is composed of tetrasaccharide repeating-unites having the following structure. →)-α- l-Fuc p-(1 → 2)-β- d-Gal p-(1 → 3)-α- d-gal pNAc-(1 → 3)-α- d-Gal pNAc-(1 → The polysaccharide contains approximately one mole of O-acetyl groups per repeating unit distributed over several positons.