STRUCTURAL ELUCIDATION OF THE LIPOPOLYSACCHARIDE CORE REGION OF THE O-CHAIN-DEFICIENT MUTANT STRAIN A28 FROM PSEUDOMONAS-AERUGINOSA SEROTYPE O6 (INTERNATIONAL ANTIGENIC TYPING SCHEME)
H. Masoud et al., STRUCTURAL ELUCIDATION OF THE LIPOPOLYSACCHARIDE CORE REGION OF THE O-CHAIN-DEFICIENT MUTANT STRAIN A28 FROM PSEUDOMONAS-AERUGINOSA SEROTYPE O6 (INTERNATIONAL ANTIGENIC TYPING SCHEME), Journal of bacteriology, 177(23), 1995, pp. 6718-6726
The lipopolysaccharide (LPS) of the Pseudomonas aeruginosa serotype 06
rough-type mutant A28 was isolated by a modified phenol-chloroform-pe
troleum ether extraction method, Deoxycholate-polyacrylamide gel elect
rophoresis indicated a single band with mobility similar to that of th
e complete core region of the wild-type parent serotype 06 (Internatio
nal Antigenic Typing Scheme) strain. Compositional analysis of the LPS
indicated that the core oligosaccharide was composed of D-glucose (th
ree units), L-rhamnose (one unit), 2-amino-2-deoxy-D-galactose (one un
it), L-glycero-D-manno-heptose (two units), 3-deoxy-D-manno-octulosoni
c acid (two units), L-alanine (one unit), and phosphate (two units). U
nder the mild conditions of hydrolysis with methanolic hydrogen chlori
de, a 7-O-carbamoyl substituent was observed on the second heptose res
idue, The glycan structure of the LPS was determined by employing one-
and two-dimensional nuclear magnetic resonance spectroscopy and mass
spectrometry-based methods with a backbone oligosaccharide that was ob
tained from the LPS by deacylation, dephosphorylation, and reduction o
f the terminal glucosamine. On the basis of the results of the present
study and our earlier work with the P. aeruginosa 06-derived core-def
ective mutant R5 (H. Masoud, E. Altman, J. C. Richards, and J. S. Lam,
Biochemistry, 33:10568-10578, 1994), a structural model for the compl
ete core oligosaccharide is proposed.