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Lipid A components from Pseudomonas aeruginosa PAO1 (serotype O5) and mutant strains investigated by electrospray ionization ion‐trap mass spectrometry
Author(s) -
Bedoux Gilles,
ValléeRéhel Karine,
Kooistra Oliver,
Zähringer Ulrich,
Haras Dominique
Publication year - 2004
Publication title -
journal of mass spectrometry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.475
H-Index - 121
eISSN - 1096-9888
pISSN - 1076-5174
DOI - 10.1002/jms.611
Subject(s) - chemistry , lipid a , electrospray ionization , chromatography , mass spectrometry , fragmentation (computing) , mutant , disaccharide , biochemistry , lipopolysaccharide , operating system , medicine , computer science , gene , endocrinology
The lipid A components of the Pseudomonas aeruginosa strains PAO1 (wild‐type) and derived mutants PAO1 algC ::tet and PAO1 PDO100 were isolated after mild acetic acid hydrolysis of LPS. Their structural heterogeneities were characterized using electrospray ionization (ESI) ion‐trap mass spectrometry (MS) with direct infusion in the negative ion mode without prior derivatization. The ESI‐mass spectra revealed monophosphorylated molecules corresponding to known tetra‐, penta‐ and hexaacylated structures of P. aeruginosa lipid A. The MS/MS fragmentation patterns allowed the location of fatty acyl chains on the disaccharide backbone of lipid A. In addition, a hexaacylated lipid A containing a hexadecanoyl chain was detected for the first time in strain P. aeruginosa PAO1. With multiple stages of fragmentation (MS n ), the position of this hexadecanoyl chain O ‐linked to the decanoyl chain at the C‐3 ′ position of the glucosamine backbone was determined. This sensitive method is suitable to reveal lipid A heterogeneity, i.e. the nature, number and distribution of acyl chains, without prior lipopolysaccharide purification. The lipid A from mutant strains were also characterized and significant differences were shown in the abundance of monophosphorylated lipid A components between the wild‐type and the mutant strains. Copyright © 2004 John Wiley & Sons, Ltd.