Field
Asymmetric Ion Mobility Spectrometry (FAIMS), when used in proteomics studies,
provides superior selectivity, and enables more proteins to be identified by
providing additional gas phase separation.
Here, we tested the performance of cylindrical FAIMS for the
identification and characterization of proteoforms by top-down mass
spectrometry of heterogeneous protein mixtures.
Combining FAIMS with chromatographic separation resulted in a 62%
increase in protein identifications and an 8% increase in proteoform
identifications as compared to samples analyzed without FAIMS. This increase
was attributable, in part, to improved signal-to-noise for proteoforms with
similar retention times. Additionally,
our results show that the optimal compensation voltage of any given proteoform
was correlated with the molecular weight of the analyte. Collectively these results suggest that the
addition of FAIMS can enhance top-down proteomics in both discovery and
targeted applications.
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