title: Effective coupling in biological electron transfer: exponential or complex distance dependence?
abstract: Calculations for a simple model electron transfer system and tuna cytochrome c demonstrate a dichotomy in the distance dependence of the effective coupling. In one regime, the effective coupling varies exponentially with distance and depends primarily on the average properties of the bridging material; in the other regime, the effective coupling has a complex distance dependence and is more sensitive to the details of the bridging material. Experiments and theory indicate that both regimes may occur in biological systems, providing a perspective on a recent controversy over the nature of the distance dependence.
authors.affiliation: Department of Chemistry, Harvard University, Cambridge, MA 02138.
authors.forename: J W
authors.initials: JW
authors.lastname: Evenson
authors.forename: M
authors.initials: M
authors.lastname: Karplus
mesh_terms: D000818:Animals; D003574:Cytochrome c Group / Q000737:chemistry / Q000378:metabolism*; D004579:Electron Transport; D006418:Heme / Q000737:chemistry / Q000378:metabolism*; D008433:Mathematics; D008954:Models, Biological; D008956:Models, Chemical; D014413:Tuna
chemical_list: D003574:Cytochrome c Group; D006418:Heme