title: Characterization of the O-4 phosphorylated and O-5 substituted Kdo reducing end group and sequencing of the core oligosaccharide of Aeromonas salmonicida ssp salmonicida lipopolysaccharide using tandem mass spectrometry.
abstract: The molecular structure of the wild strain of the lipopolysaccharide core of Aeromonas salmonicida, ssp salmonicida has been sequenced using tandem mass spectrometry. The core oligosaccharide was determined to contain an O-4 phosphorylated and O-5 substituted Kdo reducing group, and its structure is proposed as the follows: [structure: see text] After the core oligosaccharide of LPS was released from the lipid A portion by conventional treatment with 1% acetic acid, we demonstrated the existence of a homogeneous mixture composed mainly of the native core oligosaccharide containing the Kdo with its O-4 phosphate group intact, and a degraded core oligosaccharide mixture, which eliminated the O-4 phosphate group with extreme facility. The precise molecular structure and glycone sequence of the homogeneous mixture of phosphorylated and dephosphorylated core oligosaccharides was determined by electrospray ionization (ESI) mass spectrometry and tandem mass spectrometric analysis. CID-MS/MS of the homogeneous mixture of permethylated core oligosaccharides afforded a series of diagnostic product ions which confirmed the established sequence of the glycones to be determined. Matrix-assisted laser desorption/ionization (MALDI) tandem mass spectrometry reconfirmed the molecular structure of the dephosphorylated homogeneous permethylated mixture of the core oligosaccharides containing the diastereomeric 4,8- and 4,7-anhydro-alpha-keto acids.
authors.affiliation: Department of Fisheries and Oceans, Science Branch, Special Projects, PO Box 5667, St. John's, NL A1C 5X1, Canada and Memorial University of Newfoundland, Biochemistry Department, St. John's, NL A1C 5S7, Canada. banoubjo@dfo- mpo.gc.ca
authors.forename: Joseph
authors.initials: J
authors.lastname: Banoub
authors.forename: Anas
authors.initials: A
authors.lastname: El Aneed
authors.forename: Alejandro
authors.initials: A
authors.lastname: Cohen
authors.forename: Patrick
authors.initials: P
authors.lastname: Martin
mesh_terms: D048409:Aeromonas salmonicida / Q000378:metabolism*; D008070:Lipopolysaccharides / Q000737:chemistry*; D015394:Molecular Structure; D019081:O Antigens / Q000737:chemistry*; D010084:Oxidation-Reduction; D010766:Phosphorylation; D011135:Polysaccharides, Bacterial / Q000737:chemistry*; D021241:Spectrometry, Mass, Electrospray Ionization / Q000379:methods*; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization / Q000379:methods*
chemical_list: D008070:Lipopolysaccharides; D019081:O Antigens; D011135:Polysaccharides, Bacterial