Figure 7.

Evaluation of sulfopeptide enrichment and NL triggering data acquisition for sulfopeptide identification. Secretome samples were analyzed using either a DDA strategy (32% NCE HCD) or the 10% NCE HCD NL triggered strategy for HCD acquisition (32% NCE), with or without enrichment using TiO₂/Zr⁴⁺-IMAC enrichment (Figure 6). Listed are the total number of peptides identified, those containing either pSTY or sY before or after the removal of duplicate scan PSMs. Peptide lists were subsequently filtered for those where the site of modifications was in an acidic consensus (with D/E at the +1 or −1 position relative to Y) and then for unique sY sites. Numbers are representative of ≥2 independent experiments.