tailieunhanh - Báo cáo khoa học: Structural analysis of lipopolysaccharides from Haemophilus influenzae serotype f Structural diversity observed in three strains

Structural elucidation of the lipopolysaccharide (LPS) from threeserotypef Haemophilus influenzaeclinical isolates RM6255, RM7290and RM6252 has been achieved using NMR spectroscopy techniques and ESI-MS on O-deacyl-ated LPS and core oligosaccharide material (OS) as well as ESI-MS n on permethylated dephosphorylated OS. This is the first study to report structural details on LPS from sero-type f strains. | Eur. J. Biochem. 270 3153-3167 2003 FEBS 2003 doi Structural analysis of lipopolysaccharides from Haemophilus influenzae serotype f Structural diversity observed in three strains Hakan H. Yildirim1 Derek W. Hood2 E. Richard Moxon2 and Elke K. H. Schweda1 1 Clinical Research Centre Karolinska Institutet and University College of South Stockholm Sweden 2Molecular Infectious Diseases Group University of Oxford Department of Pediatrics Weatherall Institute of Molecular Medicine John Radcliffe Hospital Oxford UK Structural elucidation of the lipopolysaccharide LPS from three serotype f Haemophilus influenzae clinical isolates RM6255 RM7290 and RN62252 has been ahhieved using NMR spectroscopy techniques and ESI-MS on O-deacyl-ated LPS and core oligosaccharide material OS as well as ESI-MSn on permethylated dephosphorylated OS. This is the first study to report structural details on LPS from serotype f strains. We found that the LPSs of all strains were highly heterogeneous mixtures of glycoforms expressing the common H. influenzae structural element L-a-D-Hepp- 1fi2 - PEtnfi6 -L-a-D-Hepp- 1fi3 - p-D-Glcp- 1fi4 -L-a-D-Hepp- 1fi5 - PPEtnfi4 -a-Kdo- 2fi6 -lipid A with eariable length of OS chains linked to each of the heptoses. The terminal heptose HepIII in RM6255 is substituted at the O-3 position by a P-D-Glcp residue whereas HepIII in strains RM7290 and RM6252 is substituted at 0-2 by the globoside unit a-D-Galp- 1fi4 -P-D-Galp- 1fi4 -P-D-Glc or truncated eersions thereof. The central heptose HepII is substituted by an a-D-Galp- 1fi4 -P-D-Galp- 1fi4 -P-D-Glcp- 1fi4 -a-D-Glcp unit in RM7290 ndd Md62 or truncated eersions thereof. Strain RM6255 does not express galactose in its LPS and only shows a cellobiose unit elongating from HepII P-D-Glcp- 1fi4 -a-D-Glcp . ESI-MSn on dephosphorylated and permethylated OS proeided information on the existence of additional minor isomeric glycoforms. Keywords Haemophilus influenzae lipopolysaccharide .