Metabolite discovery through global annotation of untargeted metabolomics data
Chen, L.; Lu, W.; Wang, L.; Xing, X.; Teng, X.; Zeng, X.; Muscarella, A. D.; Shen, Y.; Cowan, A. J.; McReynolds, M. R.; Kennedy, B.; Lato, A. M.; Campagna, S. R.; Singh, M.; Rabinowitz, J. D.
Show abstract
Liquid chromatography-high resolution mass spectrometry (LC-MS)-based metabolomics aims to identify and quantitate all metabolites, but most LC-MS peaks remain unidentified. Here, we present a global network optimization approach, NetID, to annotate untargeted LC-MS metabolomics data. The approach aims to generate, for all experimentally observed ion peaks, annotations that match the measured masses, retention times, and (when available) MS/MS fragmentation patterns. Peaks are connected based on mass differences reflecting adducting, fragmentation, isotopes, or feasible biochemical transformations. Global optimization generates a single network linking most observed ion peaks, enhances peak assignment accuracy, and produces chemically-informative peak-peak relationships, including for peaks lacking MS/MS spectra. Applying this approach to yeast and mouse data, we identified five novel metabolites (thiamine derivatives and N-glucosyl-taurine). Isotope tracer studies indicate active flux through these metabolites. Thus, NetID applies existing metabolomic knowledge and global optimization to annotate untargeted metabolomics data, revealing novel metabolites.
Matching journals
The top 4 journals account for 50% of the predicted probability mass.