USE OF MASS-SPECTROMETRY TO COMPARE 3 O-CHAIN-LINKED AND FREE LIPOPOLYSACCHARIDE CORES - DIFFERENCES FOUND IN BORDETELLA-PARAPERTUSSIS

Plasma desorption mass spectrometry and matrix-assisted laser desorpti on/ionization mass spectrometry methods were used to investigate the m olecular differences between lipopolysaccharide free core molecules an d core molecules substituted by O-chains in Bordetella parapertussis, Salmonella ohio, and Escherichia coil O119. The B. parapertussis analy sis indicated a difference in mass of 569 amu corresponding to 3 dista l sugars comprising terminal residues of heptose, galactosaminuronic a cid, and, N-acetyl-N-methylfucosamine, a result supported by evidence from NMR and serology. No differences were evident in the analyses of cores in either S. ohio or E. coli O119, although the first O-chain un it carried by S. ohio core lacked a terminal glucose present in the re sidual O-chain repeating units.