Elucidation of the structure of the core region and the complete structure of the R-type lipopolysaccharide of Erwinia caratovora FERM P-7576

An R-type lipopolysaccharide (LPS) from Erwinia carotovora strain FERM P-7576 was studied after strong alkaline degradation and mild acid hydrolysis. The resulting products were analysed by fast-atom bombardment mass spectrometry, one-and two-dimensional H-1 and C-13 NMR spectroscopy, dephosphorylation and methylation analysis. The following structure was proposed for the core region of the LPS: [GRAPHICS] where Hep is L-glycero-D-manno-heptose and Kdo is 3-deoxy-D-manno-octulosonic acid. Some LPS species lack the beta-D-Galp residue or the beta-D-Galp-(1-7)-alpha-Hepp disaccharide. With the known structures of lipid A [Fukuoka, S., Kamishima, H., Nagawa, Y., Nakanishi, H., Ishikawa, K., Niwa, Y., Tamiya, E. & Karube, I. (1992) Arch. Microbiol. 157, 311-318] and the core moiety, the complete LPS structure was established and confirmed by matrix-assisted laser desorption/ionisation time-of-flight mass spectrometry of the native and O-dcacylated LPS.