Characterization of a novel lipid A structure isolated from Azospirillum lipoferum lipopolysaccharide.
The structure of lipid A from Azospirillum lipoferum, a plant-growth-promoting rhizobacterium, was investigated. It was determined by chemical analysis, mass spectrometric methods, as well as 1D and 2D NMR spectroscopy. Because of the presence of substituents, the investigated lipid A differs from typical enterobacterial lipid A molecules. Its backbone is composed of a beta-(1,6)-linked D-glucosamine disaccharide but lacks phosphate residues. Moreover, the reducing end of the backbone (position C-1) is substituted with alpha-linked d-galacturonic acid. 3-hydroxypalmitoyl residues are exclusively connected to amino groups of the glucosamine disaccharide. Hydroxyls at positions C-3 and C-3' are esterified with 3-hydroxymyristic acids. Primary polar fatty acids are partially substituted by nonpolar fatty acids (namely, 18:0, 18:1 or 16:0), forming acyloxyacyl moieties.
Choma
Adam
A
Department of General Microbiology, Maria Curie-Sklodowska University, 19, Akademicka St., 20-033 Lublin, Poland. achoma@hektor.umcs.lublin.pl
Komaniecka
Iwona
I
D042081:Azospirillum lipoferum / Q000737:chemistry*; D008050:Lipid A / Q000737:chemistry* / Q000302:isolation & purification*; D009682:Magnetic Resonance Spectroscopy; D013058:Mass Spectrometry; D015394:Molecular Structure
D008050:Lipid A