Adsorption of wild-type and double-mutant cathepsin G to aprotinin-agarose in the presence of brefeldin A. (A) RBL/CatG and (B) RBL/CatG/Gly₂₀₁/▵Gly₁₉Glu₂₀ cells were preincubated with brefeldin A (5 μg/mL) for 60 minutes, whereupon pulse-labeling and chase of the label were performed in the continued presence of brefeldin A. Lysis and adsorption to aprotinin was performed as described in the legend to Fig 4. The fluorograms were exposed for 7 days.