tailieunhanh - Báo cáo Y học: Structural analysis of the lipopolysaccharide from nontypeable Haemophilus influenzae strain 1003

Structural analysis of the lipopolysaccharide (LPS) of nontypeableHaemophilus in¯uenzaestrain 1003 has been achieved by the application of high-®eld NMR techniques, ESI-MS, capillary electrophoresis coupled to ESI-MS, composition and linkage analyses on O-deacylated LPS and core oligosaccharide material. It was found that the LPS contains the common structural element of H. | Eur. J. Biochem. 269 808-818 2002 FEBS 2002 Structural analysis of the lipopolysaccharide from nontypeable Haemophilusinfluenzae strain 1003 Martin Mansson1 Derek W. Hood2 Jianjun Li3 James C. Richards3 E. Richard Moxon2 and Elke K. H. Schweda1 1 Clinical Research Centre Karolinska Institutet and University College of South Stockholm Huddinge Sweden 2Molecular Infectious Diseases Group and Department of Paediatrics Weatherall Institute of Molecular Medicine John Radcliffe Hospital Oxford UK 3Institute for Biological Sciences National Research Council of Canada Ottawa Ontario Canada Structural analysis of the lipopolysaccharide LPS of nontypeable Haemophilus influenzae strain 1003 has been achieved by the application of high-held NMR techniques ESI-MS capillary electrophoresis coupled to ESI-MS composition and linkage analyses on O-deacylated LPS and core oligosaccharide material. It was found that the LPS contains the common structural element of H. influenzae L-a-D-Hepp- 1 2 - PEtn 6 -L-a-D-Hepp- 1 3 - b-D-Glcp- 1 4 -L-a-D-Hepp- 1 5 - PP Etn 4 -a-Kdop- 2 6 -Lipid A in which the b-D-Glcp residue is substituted by phosphocholine at O-6 and an acetyl group at O-4. A second acetyl group is located at O-3 of the distal heptose residue HepIII . HepIII is chain elongated at O-2 by either a b-D-Glcp residue major lactose or sialyllactose minor . a-Neu5Ac- 2 3 -b-D-Galp- 1 4 -b-D-Glcp where a third minor acetylation site was identihed at the glucose residue. Disialylated species were also detected. In addition a minor substitution of ester-linked glycine at HepIII and Kdo was observed. Keywords Haemophilus lipopolysaccharide sialic acid phosphocholine CE-ESI-MS MS. Haemophilus influenzae is an important cause of human disease worldwide and is found in both encapsulated types a-f and unencapsulated nontypeable forms. Nontypeable H. influenzae NTHi strains commonly colonize the nasopharynx of healthy carriers and are important causes of upper and lower respiratory tract .