The Reorganization Energy in Cytochrome c is Controlled by the Accessibility of the Heme to the Solvent
journal contributionposted on 16.12.2015, 19:31 by Carlo Augusto Bortolotti, Magdalena E. Siwko, Elena Castellini, Antonio Ranieri, Marco Sola, Stefano Corni
Elucidation of the molecular determinants of the reorganization energy λ is central to the understanding of fundamental biological processes based on energy transduction pathways. Here, we use a combined experimental/theoretical approach to electrochemically determine the reorganization energy for a number of cytochrome c variants and compute structure-related properties relevant to the kinetics of the electron transfer process through molecular dynamics simulations. We find that the exposure of the heme group to solvent controls the reorganization energy of the investigated proteins. Therefore, fine-tuning of the kinetics of the electron transfer process can be achieved through modulation of the accessibility of the iron to the surrounding water. Our findings lead the way for a new strategy for the design of protein-based bioelectronic materials, requiring fast and efficient electron transfer.