Lipopolysaccharide structures of Helicobacter pylori wild-type strain 26695 and 26695 HP0826::Kan mutant devoid of the O-chain polysaccharide component.

We describe a re-investigation of the structure of the lipopolysaccharide (LPS) from Helicobacter pylori genomic strain 26695 and its corresponding HP0826::Kan mutant lacking the O-chain component based on the in-depth NMR analysis of the oligosaccharide products obtained through the use of various degradation procedures performed on the purified LPS from both strains, as well as CE-MS data. New structural evidence indicates the presence of the linear arrangement of glucan and heptan portions of the LPS attached through -6-α-DDHep-3-α-L-Fuc-3-β-GlcNAc- fragment to the inner core DD-heptose residue. This structure differs from previously reported structures of the H. pylori 26695 LPS in several aspects. Crown