Fig. 5From: Directed evolution and secretory expression of a pyrethroid-hydrolyzing esterase with enhanced catalytic activity and thermostabilityEffect of pH on the activity of the wild-type enzyme (filled square), M1 (filled circle), M2 (filled triangle), and M3 (open square). The optimum pH was measured using ρ-nitrophenyl acetate as a substrate at 55 °C. pH stability was tested after incubation of the purified enzyme for 24 h at 30 °C in the above different buffers. Data points are the average of triplicate measurements, and error bars represent the standard deviationBack to article page