title: Structural determination of lipid A from gram negative bacteria using laser desorption mass spectrometry.
abstract: Laser desorption mass spectrometry has been employed for the structural determination of lipid A components derived from the lipopolysaccharides (LPS) of gram-negative bacteria. Mass spectra were obtained for methylated monophosphoryl lipid A from Neisseria gonorrhoeae and Rhodopseudomonas sphaeroides, for diphosphoryl lipid A from Escherichia coli and for the intact LPS from the Re Mutant of E. coli consisting of triphosphoryl lipid A and two KDO (2-keto-3-deoxyoctonate) units. Fragmentation of the phosphate (or pyrophosphate) on the reducing glucosamine is followed by fragmentation of acyl-linked fatty acids. Also observed are fragment ions which correspond to the distal portion of the molecule.
mesh_terms: D004926:Escherichia coli / Q000276:immunology; D006090:Gram-Negative Bacteria / Q000276:immunology*; D007834:Lasers; D008050:Lipid A / Q000302:isolation & purification; D008070:Lipopolysaccharides / Q000302:isolation & purification; D013058:Mass Spectrometry / Q000379:methods; D009344:Neisseria gonorrhoeae / Q000276:immunology; D012242:Rhodobacter sphaeroides / Q000276:immunology
chemical_list: D008050:Lipid A; D008070:Lipopolysaccharides