Nitrate as a probe of cytochrome c surface: Crystallographic identification of crucial “hot spots” for protein-protein recognition

In electron transfer complexes, the redox-dependent variations of cytochrome c surface drive the docking/undocking processes. Using nitrate anion as ionic probe, the X-ray structures have evidenced the hot spots of the electrostatic surface of cytochrome c. This analysis provides support for a sliding mechanism of cytochrome c on mitochondrial respirasome.