Structural characterization of lipid A component of Erwinia carotovora lipopolysaccharide
Fukuoka, S. | Kamishima, H. | Nagawa, Y. | Nakanishi, H. | Ishikawa, K. | Niwa, Y. | Tamiya, E. | Karube, I.
The chemical structure of the lipid A component of lipopolysaccharide excreted into the liquid medium by the plant pathogenic enterobacterium Erwinia carotocora FERM P-7576 was characterized. It consists of a beta-1',6-linked glucosamine disaccharide which carries ester- and amide-bound fatty acids and phosphate similar to the lipid A from other gram-negative bacteria. The lipid A preparation was not uniform in the number and composition of the fatty acids linked to the disaccharide. Four prominent lipids A were involved, they were composed of five to seven residues of fatty acid. Among them the major component was hexa-acyl lipid A, in which the hydroxyl group at position 3' and the amino group of the non-reducing glucosamine unit carry 3-dodecanoyloxytetradecanoyl residues. Positions 2 and 3 of the reducing glucosamine unit were substituted by 3-hydroxy-tetradecanoic acid. In the hepta-acyl lipid A, an additional hexadecanoic acid was linked to the hydroxyl group of the 3-hydroxytetradecanoyl residue at position 2 of the hexa-acyl lipid A. Two penta-acyl lipids A were the homologs of the hexa-acyl lipid A with decreasing acylation. Dodecanoic acid was missing from one, and 3-hydroxytetradecanoic acid from another. 3-Dodecanoyloxytetradecanoyl residue at position 3' differentiates E. carotovora lipid A from that of other gram-negative bacteria.Show more [+] Less [-]