Studies on the chemical structure of the core-lipid A region of the lipopolysaccharide of Acinetobacter calcoaceticus NCTC 10305. Detection of a new 2-octulosonic acid interlinking the core oligosaccharide and lipid A component.
Lipopolysaccharide of Acinetobacter calcoaceticus NCTC 10305 was treated with acid (0.1 M HCl, 100 degrees C, 1 h). The product obtained (LPSdegr) was subjected to various modification and degradation procedures including reduction, hydrazinolysis and strong acid hydrolysis. Methylation analysis of purified part structures revealed the presence of a 4'-phosphorylated (beta 1'-6)-linked D-glucosamine disaccharide (lipid A backbone), which carried in position 6' a hitherto unknown 2-octulosonic acid (OclA) in highly acid-stable linkage. It was further shown that OclA is substituted in position 5 by a glucose tetramer, the reducing residue of which is phosphorylated. The hydrophilic region of the LPSdegr could thus be characterized as a phosphorylated heptasaccharide of the following structure: (Formula: see text).
D000150:Acinetobacter / Q000032:analysis*; D002240:Carbohydrate Sequence; D055598:Chemical Phenomena; D002627:Chemistry, Physical; D008050:Lipid A / Q000032:analysis*; D008070:Lipopolysaccharides / Q000032:analysis*; D013058:Mass Spectrometry; D013400:Sugar Acids / Q000032:analysis*
D008050:Lipid A; D008070:Lipopolysaccharides; D013400:Sugar Acids; C051933:2-octulosonic acid