Open AccessStructural elucidation of the lipopolysaccharide core regions of the wild‐type strain PAO1 and O‐chain‐deficient mutant strains AK1401 and AK1012 from Pseudomonas aeruginosa serotype O5
Author(s) -
Sadovskaya Irina,
Brisson JeanRobert,
Lam Joseph S.,
Richards James C.,
Altman Eleonora
Publication year - 1998
Publication title -
european journal of biochemistry
Language(s) - English
Resource type - Journals
eISSN - 1432-1033
pISSN - 0014-2956
DOI - 10.1046/j.1432-1327.1998.2550673.x
Subject(s) - heptose , chemistry , strain (injury) , lipopolysaccharide , lipid a , oligosaccharide , pseudomonas aeruginosa , mutant , stereochemistry , biochemistry , bacteria , biology , gene , genetics , anatomy , endocrinology
Lipopolysaccharide (LPS) of the Pseudomonas aeruginosa serotype O5 wild‐type strain PAO1 and derived rough‐type mutant strains AK1401 and AK1012 was isolated by a modified phenol/chloroform/petroleum‐ether extraction method. Deoxycholate/PAGE of the LPS from the rough mutant AK1401 indicated two bands near the dye front with mobilities similar to those of the parent strain, indicating that both LPS contain a complete core and a species comprising a core and one repeating unit. Composition analysis of the LPS from strains PAO1 and AK1401 indicated that the complete core oligosaccharide was composed of D ‐glucose (four units), L ‐rhamnose (one unit), 2‐amino‐2‐deoxy‐ D ‐galactose (one unit), L glycero ‐ D ‐ manno ‐heptose (Hep; two units), 3‐deoxy‐ D ‐ manno ‐octulosonic acid (Kdo; two units), L alanine (one unit) and phosphate (three units). The glycan structure of the LPS was determined by one‐dimensional and two‐dimensional (2D) NMR techniques in combination with MS‐based methods on oligosaccharide samples obtained from the LPS by delipidation procedures. The locations of three phosphomonoester groups on the first heptose residue were established by a two‐dimensional 31 P (ω 1 )‐half‐filtered COSY experiment on the reduced core oligosaccharide sample of the LPS from the wild‐type strain. The presence of a 7‐ O ‐carbamoyl substituent was observed on the second heptose. The structure of the core region of the O‐chain‐deficient LPS from P . aeruginosa serotype O5 is as follows :R 2 CONH 2 P ↓↓↓376R 1 ←4)‐α‐ D ‐Gal p N‐(1←3)‐ L ‐α‐ D ‐Hep p ‐(1←3)‐ L ‐α‐ D ‐Hep p ‐(1←5)‐α‐ D ‐Kdo p ‐(2←6)‐lipid A2244↑↗↖↑ L ‐Ala P P2α‐ D ‐Kdo p where R 1 is β‐ D ‐Glc p ‐(1←2)‐α‐ L ‐Rha p ‐(1←6)‐α‐ D ‐Glc p‐ (1← and R 2 is α‐ D ‐Glc p‐ (1←6)‐β‐ D ‐Glc p ‐(1←. A structural model is presented that is also representative of that for P. aeruginosa serotype O6 LPS. A revised structure for the serotype O6 mutant strain A28 is presented.