title: Chemical structure of lipid A isolated from Comamonas testosteroni lipopolysaccharide.
abstract: The chemical structure of lipid A of lipopolysaccharide isolated from Comamonas testosteroni was determined by quantitative analysis, methylation analysis, mass spectrometry and NMR spectroscopy. The lipid A backbone was found to consist of 6-O-(2-deoxy-2-amino-beta-D-glucopyranosyl)-2-deoxy-2-amino-alpha-D-g luc ose which was phosphorylated in positions 1 and 4'. Hydroxyl groups at positions 4 and 6' were unsubstituted, and position 6' of the non-reducing terminal residue was identified as the attachment site of the polysaccharide part. Liquid secondary-ion/mass spectrometry revealed a pseudomolecular ion at m/z 1572 [M-H]- as a major diphosphoryl lipid component carrying six acyl groups. Fatty acid distribution analysis and electrospray ionization/mass spectrometry of the lipid A showed that positions 2,2',3, and 3' of the sugar backbone were N-acylated or O-acylated by (R)-3-hydroxydecanoic acid, and that the hydroxyl groups of the amide-linked residues attached to positions 2 and 2' were further O-acylated by tetradecanoic and dodecanoic acids, respectively.
authors.affiliation: Division of Microbiology, National Institute of Health Sciences, Tokyo, Japan.
authors.forename: T
authors.initials: T
authors.lastname: Iida
authors.forename: Y
authors.initials: Y
authors.lastname: Haishima
authors.forename: A
authors.initials: A
authors.lastname: Tanaka
authors.forename: K
authors.initials: K
authors.lastname: Nishiyama
authors.forename: S
authors.initials: S
authors.lastname: Saito
authors.forename: K
authors.initials: K
authors.lastname: Tanamoto
mesh_terms: D002240:Carbohydrate Sequence; D005227:Fatty Acids / Q000737:chemistry; D006088:Gram-Negative Aerobic Bacteria / Q000737:chemistry*; D006900:Hydroxylation; D008050:Lipid A / Q000737:chemistry* / Q000302:isolation & purification; D008070:Lipopolysaccharides / Q000737:chemistry*; D009682:Magnetic Resonance Spectroscopy; D013058:Mass Spectrometry; D008745:Methylation; D008969:Molecular Sequence Data; D015394:Molecular Structure; D010710:Phosphates / Q000737:chemistry
chemical_list: D005227:Fatty Acids; D008050:Lipid A; D008070:Lipopolysaccharides; D010710:Phosphates