LIPOPOLYSACCHARIDE OF THE HELICOBACTER-PYLORI TYPE STRAIN NCTC-11637 (ATCC-43504) - STRUCTURE OF THE O-ANTIGEN CHAIN AND CORE OLIGOSACCHARIDE REGIONS

Smooth- and rough-form lipopolysaccharides from phenol-water extractio n of cells from Helicobacter pylori type strain NCTC 11637 were isolat ed as the water-soluble component of high-M(r) and water-insoluble low -Mr gel. Structural investigations were performed on the intact water- soluble smooth-form lipopolysaccharide, various oligosaccharides forme d as chemical and enzymic degradation products, and three oligosacchar ide fractions liberated by acetic acid hydrolysis from the water-insol uble rough-form lipopolysaccharide. A structure is proposed for the co mplete polysaccharide component of the smooth-form lipopolysaccharide comprising the O antigen chain, an intervening region, and the inner c ore oligosaccharide on the basis of H-1 and C-13 NMR experiments, fast atom bombardment/mass spectrometry, and methylation linkage analysis of permethylated oligo- and polysaccharide derivatives. The most strik ing feature of the O antigen region in the lipopolysaccharide is the p resence of extended chains with fucosylated and nonfucosylated N-acety llactosamine (LacNAc) units that mimic human cell surface glycoconjuga tes in normal human granulocytes. The chains are terminated by di- or trimeric Lewis(x) (Le(x)) determinants, which are also found in tumor- associated carbohydrate antigens in many adenocarcinomas.