An indinavir resistant precursor is not resistant to darunavir inhibition. An indinavir resistant mutation (V77I/V82D) was introduced to the GST-M1-PRNL-HA backbone. Autoprocessing of the resulting construct with increasing concentrations of indinavir (A) or Darunavir (C) was compared to that of the parental precursor in the presence of indinavir (B) and darunavir (Figure 2D). Each blot was simultaneous probed and visualized through two infrared channels. The asterisks denote the self degradation IC50 of the released PR-HA; the open triangles denote the apparent IC50 of the cleavage reaction. The amounts of the released PR-HA from the parental (open circle) and mutant (solid square) precursor were quantified, normalized, and plotted against indinavir (D) or darunavir (D, inset) concentrations.