Modulating the pro-apoptotic activity of cytochrome c at a biomimetic electrified interface

Programmed cell death via apoptosis is a natural defence against excessive cell division, crucial for foetal development to maintenance of homeostasis and elimination of precancerous and senescent cells. Here we demonstrate an electrified liquid bio-interface that replicates the molecular machinery of the inner mitochondrial membrane at the onset of apoptosis. By mimicking in vivo cytochrome c (Cyt c) interactions with cell membranes, our platform allows us to modulate the conformational plasticity of the protein by simply varying the electrochemical environment at an aqueous|organic interface. Remarkably, we observe interfacial electron transfer between an organic electron donor decamethylferrocene and O₂, electrocatalysed by Cyt c. This interfacial reaction requires partial Cyt c unfolding, mimicking Cyt c in vivo peroxidase activity. As proof-of-concept, we use our electrified liquid bio-interface to identify drug molecules, such as bifonazole, that can potentially downregulate Cyt c and protect against uncontrolled neuronal cell death in neurodegenerative disorders.