Figure 1:

Box plot generated from the percent unique peptide sequences for all 6 proteolytic digests (Arg-C, Asp-N, Chym, Glu-C, Lys-C and Tryp) when the human and mouse databases are analyzed either separately (category 1) or together (category 2). The high sequence homology between the human and mouse protease creates a significant decrease in the percent of unique peptides, and a corresponding increase in the percent of shared peptides.