Structural studies of the O-specific chain of Hafnia alvei strain 32 lipopolysaccharide

The structure of the O-specific side-chain of the Hafnia alvei strain 32 lipopolysaccharide has been investigated. Methylation analysis, partial acid hydrolysis, Smith degradations, NMR spectroscopy, MALDI-TOF and FAB mass spectrometry in combination with collision-induced decomposition MS/MS were the principal methods used. It is concluded that the polysaccharide is composed of pentasaccharide repeating units having the following structure which is partially O-acetylated in the 2- (20%) and 3- (50%) position of the → 4)-α-d-Gal pA-(1 → residue. A MALDI-TOF mass spectrum of the O-specific chains indicated that they consisted of up to 16 repeating units.