title: Lipopolysaccharide of Rhodospirillum salinarum 40: structural studies on the core and lipid A region.
abstract: The structural elucidation of lipid A of the cell wall lipopolysaccharide (LPS) of Rhodospirillum salinarum 40 by chemical methods and laser desorption mass spectrometry revealed the presence of a mixed lipid A composed of three different 1,4'bisphosphorylated beta (1 --> 6)-linked backbone hexosaminyl-hexosamine disaccharides, i.e. those composed of GlcN --> GlcN, 2,3-diamino-2,3-dideoxy-D-Glc-(DAG --> DAG, and DAG --> GlcN. Lipid A of R. salinarum contained preferentially 3-OH-18:0 and 3-OH-14:0 as amide-linked and cis delta 11-18:1 and c19:0 as ester-linked fatty acids. The mass spectra of the liberated acyl-oxyacyl residues proved the concomitant presence of 3-O-(cis delta 11-18:1)-18:0 and 3-O-(c19:0)-14:0 as the predominating diesters in this mixed lipid A. The glycosidically linked and the ester-linked phosphate groups of the backbone disaccharide were neither substituted by ethanolamine, phosphorylethanolamine, nor by 4-amino-4-deoxy-L-arabinose, in contrast to most of the enterobacterial lipid As. In the core oligosaccharide fraction, a HexA (1 --> 4)HexA(1 --> 5)Kdo-trisaccharide was identified by methylation analysis. The terminal HexA (hexuronic acid) is possibly 4-OMe-GalA, a component described here as an LPS constituent for the first time. LPS of R. salinarum showed a lethality in C57BL/10 ScSN (LPS-responder)-mice) of an order of 10(-1)-10(-2) of that reported for Salmonella abortus equi LPS, and it was also capable of inducing TNF alpha and IL6 in macrophages of C57BL/10ScSN mice.
mesh_terms: D000818:Animals; D002240:Carbohydrate Sequence; D004187:Disaccharides / Q000032:analysis; D005227:Fatty Acids / Q000032:analysis; D015850:Interleukin-6 / Q000096:biosynthesis; D008050:Lipid A / Q000737:chemistry*; D008070:Lipopolysaccharides / Q000737:chemistry* / Q000494:pharmacology / Q000633:toxicity; D008264:Macrophages / Q000187:drug effects / Q000378:metabolism; D051379:Mice; D008810:Mice, Inbred C57BL; D008969:Molecular Sequence Data; D010710:Phosphates / Q000032:analysis; D012246:Rhodospirillum / Q000737:chemistry*; D014312:Trisaccharides / Q000032:analysis; D014409:Tumor Necrosis Factor-alpha / Q000096:biosynthesis
chemical_list: D004187:Disaccharides; D005227:Fatty Acids; D015850:Interleukin-6; D008050:Lipid A; D008070:Lipopolysaccharides; D010710:Phosphates; D014312:Trisaccharides; D014409:Tumor Necrosis Factor-alpha