Open AccessStructural analysis of lipopolysaccharides from Haemophilus influenzae serotype f
Author(s) -
Yildirim Håkan H.,
Hood Derek W.,
Moxon E. Richard,
Schweda Elke K. H.
Publication year - 2003
Publication title -
european journal of biochemistry
Language(s) - English
Resource type - Journals
eISSN - 1432-1033
pISSN - 0014-2956
DOI - 10.1046/j.1432-1033.2003.03693.x
Subject(s) - heptose , chemistry , haemophilus influenzae , stereochemistry , nuclear magnetic resonance spectroscopy , strain (injury) , lipopolysaccharide , serotype , residue (chemistry) , lipid a , cellobiose , microbiology and biotechnology , biochemistry , biology , hydrolysis , gene , mutant , anatomy , cellulase , endocrinology , antibiotics
Structural elucidation of the lipopolysaccharide (LPS) from three serotype f Haemophilus influenzae clinical isolates RM6255, RM7290 and RM6252 has been achieved using NMR spectroscopy techniques and ESI‐MS on O‐deacylated 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 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 ‐α‐ d ‐Hep p ‐(1→2)‐[ P Etn→6]‐ l ‐α‐ d ‐Hep p ‐(1→3)‐[β‐ d ‐Glc p ‐(1→4)]‐ l ‐α‐ d ‐Hep p ‐(1→5)‐[ PP Etn→4]‐α‐Kdo‐(2→6)‐lipid A with variable 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 β‐ d ‐Glc p residue whereas HepIII in strains RM7290 and RM6252 is substituted at O‐2 by the globoside unit (α‐ d ‐Gal p ‐(1→4)‐β‐ d ‐Gal p ‐(1→4)‐β‐ d ‐Glc) or truncated versions thereof. The central heptose (HepII) is substituted by an α‐ d ‐Gal p ‐(1→4)‐β‐ d ‐Gal p ‐(1→4)‐β‐ d ‐Glc p ‐(1→4)‐α‐ d ‐Glc p unit in RM7290 and RM6252 or truncated versions thereof. Strain RM6255 does not express galactose in its LPS and only shows a cellobiose unit elongating from HepII (β‐ d ‐Glc p ‐(1→4)‐α‐ d ‐Glc p ). ESI‐MS n on dephosphorylated and permethylated OS provided information on the existence of additional minor isomeric glycoforms.