Biological electron-transfer reactions.

A wide range of biological processes makes extensive use of electron-transfer reactions. Rigorous characterization of a biological electron-transfer reaction requires a combination of kinetic, thermodynamic, structural and theoretical methods. The rate of electron transfer from an electron donor to an electron acceptor through a protein is dependent on the difference in reduction potential of the electron acceptor and electron donor and the distance over which electron transfer occurs. The manner in which the rate of electron transfer also depends on the structure of the protein located between the electron donor and acceptor sites remains an active topic of investigation. Diverse protein-engineering strategies are providing new insights into fundamental mechanistic considerations regarding electron-transfer properties of biological molecules, and they can provide novel means by which insights concerning biological electron-transfer reactions can be employed to develop new and useful types of chemistry.