| Autor: |
Yuly JL; Department of Physics, Duke University, Durham, NC 27708., Zhang P; Department of Chemistry, Duke University, Durham, NC 27708; peng.zhang@duke.edu david.beratan@duke.edu., Lubner CE; Biosciences Center, National Renewable Energy Laboratory, Golden, CO 80401., Peters JW; Institute of Biological Chemistry, Washington State University, Pullman, WA 99163., Beratan DN; Department of Physics, Duke University, Durham, NC 27708; peng.zhang@duke.edu david.beratan@duke.edu.; Department of Chemistry, Duke University, Durham, NC 27708.; Department of Biochemistry, Duke University, Durham, NC 27710. |
| Abstrakt: |
For decades, it was unknown how electron-bifurcating systems in nature prevented energy-wasting short-circuiting reactions that have large driving forces, so synthetic electron-bifurcating molecular machines could not be designed and built. The underpinning free-energy landscapes for electron bifurcation were also enigmatic. We predict that a simple and universal free-energy landscape enables electron bifurcation, and we show that it enables high-efficiency bifurcation with limited short-circuiting (the EB scheme). The landscape relies on steep free-energy slopes in the two redox branches to insulate against short-circuiting using an electron occupancy blockade effect, without relying on nuanced changes in the microscopic rate constants for the short-circuiting reactions. The EB scheme thus unifies a body of observations on biological catalysis and energy conversion, and the scheme provides a blueprint to guide future campaigns to establish synthetic electron bifurcation machines. |
