Communication in a Protein Stack: Electron Transfer between Cytochrome c and Bilirubin Oxidase within a Polyelectrolyte Multilayer

Assemblies of proteins and enzymes can serve as a model for mimicking biological signal transfer. A polyelectrolyte multilayer (see picture) of an electron-transfer protein (cytochrome c, red) and a copper enzyme (bilirubin oxidase, blue) has catalytic properties for four-electron oxygen reduction. The proposed architecture guarantees efficient protein–protein interaction without an additional redox mediator.