Effect of upper length limit on predicted proteome coverage. Upper length limit of identifiable peptides effects predicted proteome coverage. Theoretical residue-level proteome coverage keeping peptides with lengths (a) 5–20, (b) 5–30, (c) 5–40, and (d) 5–100. As the maximum length of identifiable peptides increases, the total theoretical proteome coverage increases, but the depletion of K and R remains. As the upper length limit increases, the theoretical coverage maximum increases.