... cellobiose (pH 4.5–5.0) and of electron transfer from flavin to heme (pH 3.5–4.0) differ from each other, and the rate-limiting step of the reac-tion thus depends on the pH of the reaction mixture[20,25]. ... of cellobiose caused rapidreduction of flavin, and the absorption at the isosbesticpoint of heme (449.0 nm) decreased similarly in bothFig. 1. Stereo representation of the heme inCDH and the ... transfer from CDH to cytochrome c, Phe166, which is located in the cytochromedomain and approaches one of propionates of heme, was mutated to Tyr,and the thermodynamic and kinetic properties of the...