Structure and cross-reactivity of the O-antigen of Proteus vulgaris O8

A high-molecular-mass O-specific polysaccharide was obtained by mild acid d egradation of Proteus vulgaris O8 lipopolysaccharide followed by gel permea tion chromatography. Studies of the polysaccharide by sugar and methylation analyses and H-1 and C-13 NMR spectroscopy, including 2D COSY, TOCSY, NOES Y, and PI-detected H-1, C-13 heteronuclear multiple-quantum coherence (HMQC ) experiments, demonstrated the presence of a tetrasaccharide repeating uni t having the following structure: alpha-D-Galp 1 down arrow 3 --> 3)-beta-D-GlcpA-(1 --> 4)-alpha-L-FucpNAc-( 1 --> 3)-alpha-D-GlcpNAc-(1 --> The role of an epitope associated with the alpha-L-FucpNAc-(1 --> 3)-D-Glcp NAc disaccharide in serological cross-reactivity of P. vulgaris O8 is discu ssed. (C) 1999 Elsevier Science Ltd. All rights reserved.