Figure 5.

Biochemical properties of AtPAO3. A, Relative H₂O₂ production (CPM, counts per minute normalized to controls) using Spd and Spm as substrates (10 mm each). B, HPLC analysis of the AtPAO3-dependent Spm conversion to Spd (15 min) and Put (15 and 60 min; AtPAO3+Spm), and Spd conversion to Put (15 and 60 min; AtPAO3+ Spd). A total 1 mm substrate was used and 2 μg of AtPAO3 enzyme. The peaks with retention time varying between approximately 7 to 8 min correspond to traces of benzoyl chloride used as derivatization reagent. C, AtPAO3 dependence from pH and temperature. D, Conversion of Spm to Spd and Put by AtPAO3 as a fraction of time, using 2 μg of AtPAO3 enzyme and Spm as substrate. Data are the means from three independent experiments ± se.