Open AccessStructure of the polysaccharide chain of the lipopolysaccharide from Flexibacter maritimus
Author(s) -
Vinogradov Evgeny,
MacLean Leann L.,
Crump Elizabeth M.,
Perry Malcolm B.,
Kay William W.
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.1432-1033.2003.03543.x
Subject(s) - monosaccharide , disaccharide , lipopolysaccharide , polysaccharide , bacteria , residue (chemistry) , microbiology and biotechnology , biochemistry , chemistry , biology , pathogen , stereochemistry , genetics , endocrinology
Flexibacter maritimus , a Gram‐negative bacterium, is a fish pathogen responsible for disease in finfish species and a cause of cutaneous erosion disease in sea‐caged salmonids. For the development of serology based diagnostics, protective vaccines, and a study of pathogenesis, the structural analysis of the lipopolysaccharide (LPS) produced by the bacterium has been undertaken. We now report that an acidic O‐specific polysaccharide, obtained by mild acid degradation of the F . maritimus LPS was found to be composed of a disaccharide repeating unit built of 2‐acetamido‐3‐ O ‐acetyl‐4‐[(S)‐2‐hydroxyglutar‐5‐ylamido]‐2,4,6‐trideoxy‐β‐glucose and 5‐acetamido‐7‐[(S)‐3‐hydroxybutyramido]‐8‐amino‐3,5,7,8,9‐pentadeoxynonulopyranosonic acid (Sug) having the structure: The configuration of the C‐2–C‐7 fragment of the latter monosaccharide (B) was assigned β‐ manno ; however, the configuration at C‐8 could not be established. NMR data indicate that the two monosaccharides have opposite absolute configurations. The repeating unit includes a linkage via a (S)‐2‐hydroxyglutaric acid residue, reported here for the first time as a component of a bacterial polysaccharide. The LPS was also found to contain a minor amount of a disaccharide β‐Sug‐(2‐3)‐ l ‐Rha, isolated from the products of the acidic methanolysis of the LPS.