FIG 2.

Biochemical characterization. (A) Spectroscopic characteristics of _wtUPO1 (dashed line) and the PaDa-I mutant (solid line). AU, arbitrary units. (B) Thermostability (T₅₀) of PaDa-I and different parental types. Each point represents the mean and standard deviation of 3 independent experiments. 1G to 5G, 1st generation to 5th generation. (C and D) pH activity profiles for _wtUPO1 (triangles) and PaDa-I (squares). Activities were measured in 100 mM citrate/phosphate/borate buffer at different pH values with 2 mM H₂O₂ and 0.3 mM ABTS (C) or with 1 mM H₂O₂ and 1 mM NBD (D). UPO1 activity was normalized to the optimum activity value, and each point represents the mean and standard deviation of 3 independent experiments.