tailieunhanh - Báo cáo khoa học: Structural diversity in lipopolysaccharide expression in nontypeable Haemophilus influenzae Identification of L-glycero -D-manno-heptose in the outer-core region in three clinical isolates

Structural elucidation of the lipopolysaccharide (LPS) from three nontypeable Haemophilus influenzaeclinical isolates, 1209, 1207 and 1233 was achieved using NMR spectro-scopy and ESI-MS on O-deacylated LPS and core oligo-saccharide (OS) material as well as ESI-MS n on permethylated dephosphorylated OS. It was found that the organisms expressed a tremendous heterogeneous glyco-form mixture resulting from the variable length of the OS chains attached to the common structural element of H. influenzae, L-a-D–Hepp-(1fi2)-[PEtnfi6]-L-a-D–Hepp-(1fi3)-[b-D-Glcp-(1fi4)]-L-a-D–Hepp-(1fi5)-[PPEtnfi4]-a-Kdop-(2fi6)-Lipid A. . | Eur. J. Biochem. 270 610-624 2003 FEBS 2003 doi Structural diversity in lipopolysaccharide expression in nontypeable Haemophilus influenzae Identification of L-glycero-D-manno-heptose in the outer-core region in three clinical isolates Martin Mansson1 Derek W. Hood2 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 Structural elucidation of the lipopolysaccharide LPS from three nontypeable Haemophilus influenzae clinical isolates 1209 1207 and 1233 was achieved using NMR spectroscopy and ESI-MS on O-deacylated LPS and core oligosaccharide OS material as well as ESI-MSn on permethylated dephosphorylated OS. It was found that the organisms expressed a tremendous heterogeneous glycoform mixture resulting from the variable length of the OS chains attached to the common structural element of H. influenzae L-a-D-Hepp- 1fi2 - PEtnfi6 -L-a-D-Hepp- 1fi3 - b-D-Glcp- 1fi4 -L-a-D-Hepp- 1fi5 - PPEtnfi4 -a-Kdop- 2fi6 -Lipid A. Notably the O-6 position of the b-D-Glcp residue could either be occupied by PCho or L-glycero-D-manno-heptose L D-Hep which is a location for L D-Hep that has not been seen previously in H. influenzae LPS. The outer-core L D-Hep residue was further chain elongated at the O-6 position by the struc tural element b-D-GalpNAc- 1fi3 -a-D-Galp- 1fi4 -b-D-Galp or sequentially truncated versions thereof. The distal heptose residue in the inner-core was found to be chain elongated at O-2 by the globotetraose unit b-D-GalpNAc- 1fi3 -a-D-Galp- 1fi4 -b-D-Galp- 1fi4 -b-D-Glcp or sequentially truncated versions thereof. Investigation of LPS from an lpsA mutant of isolate 1233 and a lic1 mutant of isolate 1209 was also performed which aside from confirming the functions of the gene products .