Cytochrome c as an experimental model protein.

Mitochondrial cytochrome c is among the most intensively studied of all proteins. Initial interest was in its role in the respiratory chain and as a model for studies of protein structure, folding and electron transfer. The function of cytochrome c in signalling apoptosis has brought a new wave of research into the protein. Bacterial cytochromes c are more complex and varied in function. This review highlights some of these roles and expands on systems for producing holocytochrome c proteins.