Chemical structure of lipid A isolated from Flavobacterium meningosepticum lipopolysaccharide.
The chemical structure of the lipid A of the lipopolysaccharide component isolated from Flavobacterium meningosepticum IFO 12535 was elucidated. Methylation and nuclear magnetic resonance analyses showed that two kinds of hydrophilic backbone exist in the free lipid A: a beta (1-->6)-linked 2-amino-2-deoxy-D-glucose, which is usually present in enterobacterial lipid A's, and a 2-amino-6-O-(2, 3-diamino-2,3-dideoxy-beta-D-glucopyranosyl)-2-deoxy-D-glucose, in a molar ratio of 1.00:0.35. Both backbones were alpha-glycosidically phosphorylated in position 1, and the hydroxyl groups at positions 4, 4', and 6' were unsubstituted. Liquid secondary ion-mass spectrometry revealed a pseudomolecular ion at m/z 1673 [M-H]- as a major monophosphoryl lipid A component carrying five acyl groups. Fatty acid analysis showed that the lipid A contained 1 mol each of amide-linked (R)-3-OH iC17:0, ester-linked (R)-3-OH iC15:0, amide-linked (R)-3-O-(iC15:0)-iC17:0, and both amide- and ester-linked (R)-3-OH C16:0. Fatty acid distribution analyses using several mass spectrometry determinations demonstrated that the former two constituents were distributed on positions 2 and 3 of the reducing terminal unit of the backbones and that the latter two were attached to the 2' and 3' positions in the nonreducing terminal residue.
Division of Microbiology, National Institute of Health Sciences, Setagayaku, Tokyo 158, Japan.
H
H
Kato
Y
Y
Haishima
T
T
Iida
A
A
Tanaka
K
K
Tanamoto
D000577:Amides; D002849:Chromatography, Gas; D004187:Disaccharides / Q000737:chemistry; D004952:Esters; D005417:Flavobacterium / Q000737:chemistry* / Q000276:immunology; D008401:Gas Chromatography-Mass Spectrometry; D008050:Lipid A / Q000737:chemistry* / Q000302:isolation & purification; D008070:Lipopolysaccharides / Q000737:chemistry; D008745:Methylation; D008958:Models, Molecular; D019906:Nuclear Magnetic Resonance, Biomolecular
D000577:Amides; D004187:Disaccharides; D004952:Esters; D008050:Lipid A; D008070:Lipopolysaccharides