FIGURE 7.

Comparison of the antioxidant activity of Cu²⁺-DMAV and Cu,Zn-SOD. Cytochrome c reduction assays were performed by the addition of XO (1.2 units/ml) to hypoxanthine (0.5 mm) in phosphate buffer, pH 7.8, in the presence of Cu²⁺-DMAV (A) (0 nm (a), 25 nm (b), 50 nm (c), 100 nm (d), 250 nm (e), 375 nm (f), or 500 nm (g)) or Cu,Zn-SOD (B) (0 nm (a), 0.4 nm (b), 0.8 nm (c), 1.6 nm (d), 3.2 nm (e), 6.5 nm (f), and 13 nm (g)). Progress curves are shown. Transformation of the data in A and B is shown as a function of V_max and [Cu²⁺-DMAV] (nm) (C) or [Cu,Zn-SOD] (nm) (D), respectively. Transformation of the data in C and D is shown as a function of V/v and [Cu²⁺-DMAV] (nm) (E) or [Cu,Zn-SOD] (nm) (F). V, initial velocity; v, final velocity. The linear transformation of the data suggests a catalytic process (34).