Cytochrome P450BM3is a self-sufficient fatty acid mono-oxygenase consisting of a diflavin (FAD/FMN) reductase domain and a heme domain fused together in a single polypeptide chain. The multidomain structure makes it an ideal model system for studying the mechanism of electron transfer and for understanding P450 systems in general. Here we report the redox properties of the cyto-chrome P450BM3 wild-type holoenzyme, and its isolated FADreductase andP450 heme domains, when immobilized in a didodecyldimethylammonium bromide film cast on an edge-plane graphite electrode
