GLUCOSYLATED N-ACETYLLACTOSAMINE O-ANTIGEN CHAIN IN THE LIPOPOLYSACCHARIDE FROM HELICOBACTER-PYLORI STRAIN UA861

The O-antigen chain from the lipopolysaccharide of Helicobacter pylori strain UA861 was determined to be composed of an elongated type 2 N-a cetyllactosamine backbone, -->3)-beta-D-Gal-(1-->4)-beta-D-GlcNAc-(1-] (n)-->, with approximately half of the GlcNAc units carrying a termina l alpha-d-Glc residue at the O-6 position. The O-chain of H.pylori UA8 61 was terminated by a N-acetyllactosamine [beta-D-Gal-(1-->4)-beta-D- GlcNAc] (LacNAc) epitope and did not express terminal Lewis X or Lewis Y blood-group determinants as previously found in other H.pylori stra ins, The absence of terminal Lewis X and Lewis Y blood-group epitopes and the replacement of Fuc by Glc as a side chain in the O-chain of H. pylori UA861 represents yet another type of lipopolysaccharide structu re from H.pylori species, These structural differences in H.pylori lip opolysaccharide molecules carry implications with regard to possible d ifferent pathogenic events between strains and respective hosts.