Fig. 5. (A) Steady-state rates of oxidation as a function of MG concentrations (0–15 μM) catalyzed by WT Mb, F43H Mb and F43H/H64A Mb (2 μM) in 100 mM KPi buffer at pH 6.0, using H₂O₂ (0.2 mM) as an oxidant. (B) The comparison of the catalytic efficiency of WT Mb, F43H Mb, F43H/H64A Mb and the natural enzymes.