The drug treatment group with Azeliragon and the untreated control group were both subjected to limited proteolysis using proteinase K. Because Azeliragon binds to the target protein, certain regions of the protein in the drug group are "protected" from being cut by the enzyme, unlike in the control group. High-resolution mass spectrometry was then used to detect and quantify peptides in both groups. By comparing peptide levels, we can pinpoint where Azeliragon binds, identifying potential antibacterial targets.