If you don't have the structure of the protein, use the ET Rates Calculator to find out rates:
Donor-acceptor distance: the edge-to-edge distance of the electron donor and acceptor cofactors.
Free energy: put a negative sign for exothermic (downhill) reactions, positive values indicate endothermic (uphill) reactions. If you don't know the free energy of the reaction, try 0 for an approximation.
Reorganization energy: 0.7eV is a good approximation for intra-protein electron transfer, 1.0eV is a good approximation for inter-protein electron transfer.
If you have the structure of the protein, download the ET_Rates package and follow the instructions below to calculate free energy optimized electron transfer rates.
After you get the free energy optimized electron transfer rates from the ET_Rates package, use the ET Rates Adjustor to find out the rates adjusted by free energy and reorganization energy:
If the structure of the protein is not known, electron transfer rates are calculated based on the following equations:
For exothermic (downhill) reactions (DG < 0):
For endothermic (uphill) reactions (DG > 0):
The initial constant 13 is the rate at van der Waals contact distance (R = 3.6 Å). The second term describes an approximately exponential fall-off in electron tunneling rate with distance through the insulating barrier. R is the edge-to-edge distance, The third term is the quantized Frank-Condon factor at room temperature. DG is free energy and l is reorganization energy. Both in the unit of eV.