The structure of the core part of Proteus vulgaris OX2 lipopolysaccharide.

The identity of a novel structural component, an open-chain acetalic linkage, in the core part of the lipopolysaccharide (LPS) from Proteus vulgaris serotype OX2 has been determined by extensive NMR spectroscopic analysis of fragments isolated after mild acid hydrolysis of the intact LPS. The open-chain N-acetylgalactosamine fragment is substituted in the 4-position by non-stoichiometric amounts of a beta-galactopyranose residue and the overall structure of the core is as follows: [formula: see text] All sugars except the N-acetylgalactosamine are in the pyranose form, alpha-Hep refers to L-glycero-alpha-D-manno-heptopyranose and alpha-DDHep to D-glycero-alpha-D-manno-heptopyranose. Bold italics indicate non-stoichiometric substituents.