STRUCTURAL CHARACTERIZATION OF THE LIPID-A OF BORDETELLA-PERTUSSIS 1414-ENDOTOXIN

The structure of Bordetella pertussis 1414 lipid A was investigated by classical methods of chemical analysis as well as plasma desorption m ass spectrometry and fast atom bombardment mass spectrometry. Previous analysis showed that it contained a bisphosphorylated beta-(1-->6)-li nked D-glucosamine disaccharide with hydroxytetradecanoic acid in amid e linkage. The presence of two main molecular species as seen by thin- layer chromatography was confirmed by plasma desorption mass spectrome try, in which the larger signal was attributable to a molecular ion co ntaining two glucosamine, two phosphate, one tetradecanoic acid, one h ydroxydecanoic acid, and three hydroxytetradecanoic acid residues. The ion of the smaller signal was lighter by the mass of one hydroxytetra decanoic acid residue (226 Da). The fatty acids in ester linkage were localized by chemical and fast atom bombardment mass spectrometry anal ysis. C-4 and C-6' hydroxyl groups of the backbone disaccharide were u nsubstituted, the latter being the proposed attachment site for Kdo (3 -deoxy-D-manno-octulosonic acid).