Non-Proteinaceous Complexes III and IV Mimicking Electron Transfer in the Mitochondrial Respiratory Chain

Synthetic biology pursues the understanding of biological processes and their possible mimicry with artificial bioinspired materials. We explore the redox properties of magnetic iron oxide nanoparticles to mimic the redox activity of complexes III and IV towards cytochrome c. We demonstrate that these nanoparticles, incorporated as non-proteinaceous complexes III and IV in a mitochondrial cell membrane model, catalyze electron transfer similarly to natural complexes. The associated molecular mechanism was experimentally proven in solution and in a Langmuir- Blodgett film; the protein-nanoparticle interactions are governed mainly by electrostatic forces, followed by electron transfer between the iron sites of the nanoparticles and the heme group. This work presents the first experimental demonstration that inorganic nanostructured systems may behave as proteins in the cell membrane.