title: Occurrence of an unusual hopanoid-containing lipid A among lipopolysaccharides from Bradyrhizobium species.
abstract: The chemical structures of the unusual hopanoid-containing lipid A samples of the lipopolysaccharides (LPS) from three strains of Bradyrhizobium (slow-growing rhizobia) have been established. They differed considerably from other Gram-negative bacteria in regards to the backbone structure, the number of ester-linked long chain hydroxylated fatty acids, as well as the presence of a tertiary residue that consisted of at least one molecule of carboxyl-bacteriohopanediol or its 2-methyl derivative. The structural details of this type of lipid A were established using one- and two-dimensional NMR spectroscopy, chemical composition analyses, and mass spectrometry techniques (electrospray ionization Fourier-transform ion cyclotron resonance mass spectrometry and MALDI-TOF-MS). In these lipid A samples the glucosamine disaccharide characteristic for enterobacterial lipid A was replaced by a 2,3-diamino-2,3-dideoxy-d-glucopyranosyl-(GlcpN3N) disaccharide, deprived of phosphate residues, and substituted by an α-d-Manp-(1→6)-α-d-Manp disaccharide substituting C-4' of the non-reducing (distal) GlcpN3N, and one residue of galacturonic acid (d-GalpA) α-(1→1)-linked to the reducing (proximal) amino sugar residue. Amide-linked 12:0(3-OH) and 14:0(3-OH) were identified. Some hydroxy groups of these fatty acids were further esterified by long (ω-1)-hydroxylated fatty acids comprising 26-34 carbon atoms. As confirmed by mass spectrometry techniques, these long chain fatty acids could form two or three acyloxyacyl residues. The triterpenoid derivatives were identified as 34-carboxyl-bacteriohopane-32,33-diol and 34-carboxyl-2β-methyl-bacteriohopane-32,33-diol and were covalently linked to the (ω-1)-hydroxy group of very long chain fatty acid in bradyrhizobial lipid A. Bradyrhizobium japonicum possessed lipid A species with two hopanoid residues.
authors.affiliation: From the Department of Genetics and Microbiology, Maria Curie-Sklodowska University, 20-033 Lublin and ikoma@hektor.umcs.lublin.pl.
authors.forename: Iwona
authors.initials: I
authors.lastname: Komaniecka
authors.affiliation: From the Department of Genetics and Microbiology, Maria Curie-Sklodowska University, 20-033 Lublin and.
authors.forename: Adam
authors.initials: A
authors.lastname: Choma
authors.affiliation: From the Department of Genetics and Microbiology, Maria Curie-Sklodowska University, 20-033 Lublin and.
authors.forename: Andrzej
authors.initials: A
authors.lastname: Mazur
authors.affiliation: the Divisions of Structural Biochemistry and.
authors.forename: Katarzyna A
authors.initials: KA
authors.lastname: Duda
authors.affiliation: Bioanalytical Chemistry, Research Center Borstel, Leibniz-Center for Medicine and Biosciences, 23845 Borstel, Poland.
authors.forename: Buko
authors.initials: B
authors.lastname: Lindner
authors.affiliation: Bioanalytical Chemistry, Research Center Borstel, Leibniz-Center for Medicine and Biosciences, 23845 Borstel, Poland.
authors.forename: Dominik
authors.initials: D
authors.lastname: Schwudke
authors.affiliation: the Divisions of Structural Biochemistry and.
authors.forename: Otto
authors.initials: O
authors.lastname: Holst
mesh_terms: D020369:Bradyrhizobium / Q000737:chemistry* / Q000145:classification; D002240:Carbohydrate Sequence; D005227:Fatty Acids / Q000737:chemistry*; D008050:Lipid A / Q000737:chemistry*; D008070:Lipopolysaccharides / Q000737:chemistry*; D009682:Magnetic Resonance Spectroscopy; D008969:Molecular Sequence Data; D015394:Molecular Structure; D013045:Species Specificity; D021241:Spectrometry, Mass, Electrospray Ionization; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization; D014315:Triterpenes / Q000737:chemistry
chemical_list: D005227:Fatty Acids; D008050:Lipid A; D008070:Lipopolysaccharides; D014315:Triterpenes; C071732:bacteriohopane-32-ol
keywords: Bradyrhizobium; Glycoconjugate; Hopanoid; Lipid A; Lipopolysaccharide (LPS); Long Chain Fatty Acids; Mass Spectrometry (MS); Nuclear Magnetic Resonance (NMR)