Maximizing glycoproteomics results through an integrated PASEF workflow

Glycoproteins play important roles in numerous physiological processes and are often implicated in disease. Analysis of site-specific protein glycobiology through glycoproteomics is evolving rapidly in recent years thanks to hardware and software innovations. Particularly, the introduction of Parallel Accumulation Serial Fragmentation (PASEF) on hybrid trapped ion mobility time-of-flight mass spectrometry instruments combined deep proteome sequencing with separation of (near-)isobaric precursor ions or converging isotope envelopes through ion mobility separation. However, reported use of PASEF in integrated glycoproteomics workflows to comprehensively capture the glycoproteome is still limited. To this end, we developed an integrated methodology using the timsTOF Pro 2 to enhance N-glycopeptide identifications in complex mixtures. We systematically optimized the ion optics tuning, collision energies, mobility isolation width and the use of do-pant-enriched nitrogen gas (DEN). Thus, we obtained a marked increase in unique glycopeptide identification rates compared to standard proteomics settings showcasing our results on a large set of glycopeptides. With short liquid chromatography gradients of 30 minutes, we increased the number of unique N-glycopeptide identifications in human plasma samples from around 100 identifications under standard proteomics condition to up to 1500 with our optimized glycoproteomics approach, highlighting the need for tailored optimizations to obtain comprehensive data. O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=128 SRC="FIGDIR/small/570555v2_ufig1.gif" ALT="Figure 1"> View larger version (28K): org.highwire.dtl.DTLVardef@1c89a72org.highwire.dtl.DTLVardef@113dc50org.highwire.dtl.DTLVardef@e52daborg.highwire.dtl.DTLVardef@1951b5_HPS_FORMAT_FIGEXP M_FIG C_FIG