FIGURE 4.

Effect of CTRC on the autoactivation of human anionic trypsinogen (PRSS2). Wild-type (A), L81A (B), and R122A (C) mutant anionic trypsinogen (1 μm) was incubated at 37 °C with 0–100 nm CTRC in 0.1 m Tris-HCl (pH 8.0), 1 mm CaCl₂, 25 mm NaCl, and 0.05% Tween 20 (final concentrations). At the indicated times, aliquots (10 μl) were removed, and trypsin activity was determined and expressed as described under “Experimental Procedures.” Experimental uncertainty and reproducibility are discussed under “Experimental Procedures.”