Nanospray FAIMS fractionation provides significant increases in proteome coverage of unfractionated complex protein digests

TitleNanospray FAIMS fractionation provides significant increases in proteome coverage of unfractionated complex protein digests
Publication TypeJournal Article
Year of Publication2011
AuthorsSwearingen KE, Hoopmann MR, Johnson RS, Saleem RA, Aitchison JD, Moritz RL
JournalMolecular & cellular proteomics : MCP
Date PublishedDec 20
AbstractHigh-field asymmetric waveform ion mobility spectrometry (FAIMS) is an atmospheric pressure ion mobility technique that can be used to reduce sample complexity and increase dynamic range in tandem mass spectrometry experiments. FAIMS fractionates ions in the gas-phase according to characteristic differences in mobilities in electric fields of different strengths. Undesired ion species such as solvated clusters and singly-charged chemical background ions can be prevented from reaching the mass analyzer, thus decreasing chemical noise. To date, there has been limited success using the commercially available Thermo Fisher FAIMS device with both standard ESI and nanoLC-MS. We have modified a Thermo Fisher electrospray source to accommodate a fused silica pulled tip capillary column for nanospray ionization which will enable standard laboratories access to FAIMS technology. Our modified source allows easily obtainable stable spray at flow rates of 300 nL/min when coupled with FAIMS. The modified electrospray source allows the use of sheath gas, which provides a 5-fold increase in signal obtained when nanoLC is coupled to FAIMS. In this work, nanoLC-FAIMS-MS and nanoLC-MS were compared by analyzing a tryptic digest of a 1:1 mixture of SILAC-labeled haploid and diploid yeast to demonstrate the performance of nanoLC-FAIMS-MS, at different compensation voltages, for post-column fractionation of complex protein digests. The effective dynamic range more than doubled when FAIMS was used. In total, 10,377 unique stripped peptides and 1,649 unique proteins with SILAC ratios were identified from the combined nanoLC-FAIMS-MS experiments, compared to 6,908 unique stripped peptides and 1,003 unique proteins with SILAC ratios identified from the combined nanoLC-MS experiments. This work demonstrates how a commercially-available FAIMS device can be combined with nanoLC to improve proteome coverage in shotgun and targeted type proteomics experiments.
Short TitleMol Cell Proteomics
Alternate JournalMol Cell Proteomics