Figure 2.

Reaction of MitoB with H₂O₂ to Form MitoP

(A) Oxidation of MitoB to MitoP assessed by RP-HPLC. MitoB (100 μM) was incubated at 37°C in KCl medium (pH 8.0) with no additions or with 100 μM H₂O₂ and then analyzed by RP-HPLC. A mixture of MitoB and MitoP standards (50 μM each) was also analyzed.

(B) Absorbance spectra of MitoB and MitoP (100 μM) in KCl medium, showing a large difference in absorption at 285 nm due to the phenol moiety.

(C) Progress curves for the reaction of MitoB with H₂O₂. The conversion of MitoB (100 μM) to MitoP by reaction with H₂O₂ is measured at 285 nm in KCl medium at 37°C (pH 8.0, unless otherwise indicated).

(D) Reaction of MitoB with various peroxides. The conversion rate of MitoB (100 μM) to MitoP by reaction with 500 μM of either H₂O₂, tert-butylhydroperoxide (tBHP) or cumene hydroperoxide (cumeneHP) was measured at 285 nm in KCl medium at 37°C, pH 8.0. Data are means ± SD, n = 3.