Fatty Acid Analysis Tool (FAAT): An FT-ICR MS Lipid Analysis Algorithm

Electrospray ionization mass spectrometry is becoming an established tool for the investigation of lipids. As the methods for lipid analysis become more mature and their throughput increases, computer algorithms for the interpretation of such data will become a necessity. Toward this end, an algorithm dedicated to the analysis of Fourier transform mass spectral data from lipid extracts has been developed. The algorithm, Fatty Acid Analysis Tool, termed FAAT, has been successfully used to investigate complex lipid extracts containing thousands of components, from various species of mycobacteria including M. tuberculosis and M. abscessus. FAAT is rapid, generally taking tens of seconds to interpret multiple spectra, and accessible to most users as it is implemented in Microsoft Excel Visual Basic Software. In the reduction of data, FAAT begins by scaling spectra (i.e., to account for dilution factors), identifying monoisotopic ions, and assigning isotope packets. Unique features of FAAT include the following: (1) overlapping saturated and unsaturated lipid species can be distinguished, (2) known ions are assigned from a user-defined library including species that possess methylene heterogeneity, (3) and isotopic shifts from stable isotope labeling experiments are identified and assigned (up to a user-defined maximum). In addition, abundance differences between samples grown under normal and stressed conditions can be determined. In the analysis of mycobacterial lipid extracts, FAAT has successfully identified isotopic shifts from incorporation of ¹⁵N in M. abscessus. Additionally, FAAT has been used to successfully determine differences in lipid abundances between M. tuberculosis wild-type and mutant strains.

• ac0604179si20060307_013523.zip (559 KB)

Electronic Supporting Information files are available without a subscription to ACS Web Editions. All files are copyrighted by the American Chemical Society. Files may be downloaded for personal use only. Users are not permitted to reproduce, republish, redistribute, or resell any Supporting Information, either in whole or in part, in either machine-readable form or any other form without permission from the American Chemical Society. For permission to reproduce this material, requesters must process their own requests via the Rightslink permission system. Information about how to use the Rightslink permission system can be found at http://pubs.acs.org/page/copyright/permissions.html. Please read only the part about Rightslink.