THE BIOSYNTHESIS OF LEWIS-X IN HELICOBACTER-PYLORI

The biosynthesis of the Lewis X determinant (Gal beta 1-4 [Fuc alpha 1 -3]GlcNAc beta-) in three strains of Helicobacter pylori has been inve stigated, Strains UA 861, UA 802 and UA 1182 contain alpha 1,3 fucosyl transferase and beta 1,4 galactosyltransferase activities that synthes ize the Lewis X structure by the transfer of monosaccharides from GDP- fucose and UDP-gaIactose donors, respectively. The enzyme reaction pro ducts that formed were characterized by capillary zone electrophoresis and by H-1-NMR spectroscopy. The biosynthetic pathway is therefore id entical to that found in humans, In the three strains, the fucosyltran sferase and galactosyltransferase activities differed in various cellu lar fractions, K-m values for their donor and acceptor substrates also differed.