Figure 3.

The role of hydroxyl radicals in the catalytic activity of PLDz. (A) Comparison of hydroxyl radical generation by treatment with different metal ions in the presence of H₂O₂. (B) Effects of divalent metal ions/H₂O₂ (100 μM) on the cleavage yield of PLDz. (C) Effects of Fe²⁺ (100 μM), Fe³⁺ (100 μM) and NH₄ ⁺ (200 μM) on the cleavage yield of PLDz. (D) Effects of Fenton reagent (Fe²⁺/H₂O₂, 1 μM–0.01 M) on the cleavage yield of PLDz. (E) Effect of Cu²⁺/H₂O₂ concentration (1 μM–0.01 M) on the cleavage yield of PLDz. (F) Effect of H₂O₂ concentration (10 μM–0.1 M) on the cleavage yield of PLDz in present of 100 μM Fe²⁺. Reaction condition: 300 mM NaCl and 50 mM Tris-HCl (pH 7.0) at 23 °C for 2 hr. The error bars represented the standard deviations from three repeated measurements. Cropped gels are used in Fig. 3B–F, their full-length gels are presented in Supplementary Figure 8.