FIG. 2.

Effect of pH and temperature on the activity of the Fpp1 protease. (A) The enzyme (0.2 μg) was incubated for 2 h in 600-μl portions of the buffers described in Materials and Methods containing 5 mM CaCl₂ and 1% azocasein. The value obtained at pH 6.5 was defined as 100%. (B) The enzyme (0.2 μg) was incubated in 600-μl portions of 25 mM PIPES buffer (pH 6.5) containing 1% azocasein for 2 h at various temperatures, and caseinolytic activity was measured as described in the text. Symbols: (○), calcium-free enzyme; (●) enzyme in the presence of 5 mM CaCl₂. The relative activities are averages based on two independent experiments.