Analysis of metabolic profiles (intra- or extra-cellular) by mass spectrometry

Mutants in a given metabolic context may also be classified based on their metabolic profile (1). Within the framework of this study, we do not try to identify the metabolites, but to produce profiles characteristic of mutants in LC/MS (2).
These data should permit classification of mutants which share similar profiles with each other but are different from wild type (i.e. metabolic pathways).
In some cases, this first analysis will be followed by a more detailed characterization of the metabolites which discriminate wild type from mutant. Information about the exact mass of these small metabolites should provide access to a reduced number of possible formulas.
The use of mass spectrometry in tandem (LC/MS/MS (3)) should give us access to structural information on the compound of interest.

Profiles (LC/MS) of the metabolites secreted by A. baylyi, in the wild type (WT) and mutant (KO). In ordinates : intensity of the signal detected by mass spectrometry. In abcisses : hydrophobicity of the metabolites separated in HPLC in opposite phase.

Glossary :
(1) Metabolic profile: ensemble of molecules metabolized by a living organism under certain environmental and/or genetic conditions.
(2) LC/MS: liquid phase chromatography and mass spectrometry.
(3) LC/MS/MS: liquid phase chromatography coupled with mass spectrometry in tandem mode.

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