Figure 7.

Kinetics of Compound I formation of wild-type CdChdC and variants. Spectral transition upon mixing of 2 μM wild-type (wt) CdChdC (A), Y135A (B), or H118A/Y135A (C) with 200 μM H₂O₂ in 50 mM phosphate buffer, pH 7.0. Initial spectra depicting the coproheme ferric resting state are shown in light green, and spectra of prominent intermediates are highlighted. In addition, representative monophasic time traces at 390 nm and single-exponential fits are shown together with linear plots of calculated k_obs values versus hydrogen peroxide concentration.