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, par tial acid hydrolysis, Smith degradations, NMR spectroscopy, MALDI-TOF and FAB mass spectrometry in combination with collision-induced decomp osition MS/MS were the principal methods used. It is concluded that th e 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)-alpha-D-GalpA-(1--> residue. [GR APHICS] A MALDI-TOF mass spectrum of the O-specific chains indicated t hat they consisted of up to 16 repeating units. (C) 1996 Elsevier Scie nce Ltd.