... 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]. ... transfer from flavin to heme. This phenomenonmakes it difficult to solve the redox mechanism of thisenzyme using kinetic results obtained with only WTCDH. In this study, therefore, we compared the ther-modynamic ... because of the weaker domain interaction of this mutant enzyme. The F166Y mutant is, however,useful for monitoring the electron transfer step of CDH, because the mutation affects only the electrontransfer...