Motif analysis to support DigDeAPr mechanism. (a) Distribution of quantified HEK peptide ratios using label-free peak area measurements from Fonslow et al. Tryptic site motif analysis using IceLogo6 and peptide ratios from analysis of HEK cells categorized by peak area ratios: (b) depleted (log2 ratio ≤ 1) cleaved sites (n = 5,834) versus unchanged (−1 < log2 ratio < 1) cleaved sites (n = 11,885), (c) depleted missed cleavage sites (n = 2,846) versus unchanged missed cleavage sites (n = 5,438), and (d) enriched (log2 ≥ 1) cleaved sites (n = 22,239) versus unchanged cleaved sites (n = 11,885).