Structural studies on the D-arabinose-containing lipid A from Rhodospirillum tenue 2761.
Structural studies carried out on the isolated free lipid A of Rhodospirillum tenue 2761 revealed a new type of structure for this lipid. The lipid A backbone of 1',6-linked glucosamine disaccharide (central disaccharide) is substituted by three different sugar residues: the non-reducing end of the disaccharide by 4-amino-4-deoxy-L-arabinose 1-phosphate and its reducing end glycosidically by D-arabinofuranose 1-phosphate; further, the reducing glucosamine of the disaccharide is branched to a third glucosamine residue by a 1'',4-glycosidic linkage. The amino and the hydroxyl groups of the central disaccharide are acylated by 3-hydroxydecanoic acid (amide-linked) and palmitic and myristic acids (ester-linked). Neither amino nor hydroxyl groups of the three external sugar residues are acylated. The results suggest the following chemical structure for the lipid A of R. tenue 2761: (formula: see text).
D001089:Arabinose; D055598:Chemical Phenomena; D002621:Chemistry; D005227:Fatty Acids / Q000032:analysis; D006595:Hexosamines / Q000032:analysis; D008050:Lipid A / Q000032:analysis*; D008070:Lipopolysaccharides / Q000032:analysis*; D012246:Rhodospirillum
D005227:Fatty Acids; D006595:Hexosamines; D008050:Lipid A; D008070:Lipopolysaccharides; D001089:Arabinose