Activating Metal Sites for Biological Electron Transfer

This review focuses on the unique spectroscopic features of the blue copper active sites. These reflect a novel electronic structure that activates the site for rapid long‐range electron transfer in its biological function. The role of the protein in determining the geometric and electronic structure of this site is defined, as is its contribution to function. This has been referred to as the entatic/rack‐induced state. These concepts are then extended to cytochrome c, which is also determined to be in an entatic state.