Open AccessStructure determination of the O‐antigenic polysaccharide from the enteroinvasive Escherichia coli O136
Author(s) -
Staaf Mikael,
Weintraub Andrej,
Widmalm Göran
Publication year - 1999
Publication title -
european journal of biochemistry
Language(s) - English
Resource type - Journals
eISSN - 1432-1033
pISSN - 0014-2956
DOI - 10.1046/j.1432-1327.1999.00531.x
Subject(s) - heteronuclear molecule , anomer , two dimensional nuclear magnetic resonance spectroscopy , chemistry , polysaccharide , nuclear magnetic resonance spectroscopy , stereochemistry , vicinal , nuclear overhauser effect , escherichia coli , crystallography , biochemistry , organic chemistry , gene
The structure of the O‐antigen polysaccharide of the lipopolysaccharide from the enteroinvasive Escherichia coli O136 has been elucidated. The composition of the repeating unit was established by sugar and methylation analysis together with 1 H and 13 C NMR spectroscopy. Two‐dimensional nuclear Overhauser effect spectroscopy (NOESY) and heteronuclear multiple‐bond correlation experiments were used to deduce the sequence. The absolute configuration for the nonulosonic acid (NonA) could be determined using spin‐spin coupling constants, 13 C chemical shifts and NOESY. The anomeric configuration of the NonA was determined via vicinal and geminal 13 C, 1 H coupling constants. The structure of the repeating unit of the polysaccharide from E. coli O136 is as follows, in which β‐Non p A is 5,7‐diacetamido‐3,5,7,9‐tetradeoxy‐ l glycero ‐β‐ l manno ‐nonulosonic acid: →4)‐β‐Non p A‐(2→4)‐β‐ d ‐Gal p ‐(1→4)‐β‐ d ‐Glc p NAc‐(1→