FIGURE 7. Peptidase and general proteinase activity.

Panel a contains HPLC chromatograms of angiotensin (Ang) I after incubation with human chymase, human cathepsin G, and wild type mouse cathepsin G. Peaks (as detected by monitoring absorbance at 210 nm) correspond to dipeptide HL and active octapeptide product Ang II (both resulting from hydrolysis at Phe⁸), inactive tetrapeptide DRVY and hexapeptide IHPFHL (resulting from hydrolysis at Tyr⁴), and uncleaved Ang I, as indicated. Panel b shows results of SDS-PAGE of casein after incubation with peptidases mouse cathepsin G (mCG), Ala²²⁶Glu and Ser¹⁸⁹Ala/Ala²²⁶Glu mutants, and human cathepsin G (hCG). Size in kDa and elution positions of marker proteins are indicated.