FIG. 2.

Effects of pH and temperature on the activity of the purified S. solfataricus arylesterase. The effects of pH and temperature on the activity of the purified arylesterase were determined spectrophotometrically using PA as a substrate. (A and B) The enzyme activity was examined at 60°C and the indicated pHs (A) or at pH 7.0 and the indicated temperatures (B). The pH was obtained using 100 mM sodium citrate buffer (♦) for the pH range of 5.0 to 6.0 100 mM sodium phosphate buffer (▪) for the pH range of 6.0 to 8.0, 100 mM Tris-HCl buffer (▴) for the pH range of 8.0 to 9.0, and 100 mM sodium bicarbonate buffer (•) for the pH range of 9.0 to 11.0. (C) Arrhenius plot of values from panel B. Error bars indicate standard deviations.