Fig. 5.

Completeness of proteolytic digestion. The trypsin digestion protocol was scaled up such that 750 μg of yeast cell lysate protein was digested with trypsin (at a substrate:proteinase ratio = 50:1) together with isotopically labeled QconCAT (81 μg), and at different times as indicated, the samples were removed for analysis. The extent of digestion of the analyte was assessed (a) as the proportion of unlabeled peptide (light) relative to the total pool (light + heavy). During the digestion, the samples were removed and analyzed by SDS-PAGE (b).