Redox Thermodynamics of electron transport metalloproteins

Using direct electrochemistry techniques, we tackled the problem of how and to what extent intrinsic molecularfactors and medium conditions such as the pH, ionic strength, specific anion binding, the presence of non aqueoussolvents and the temperature control the reduction potential (E °') of the metal center in ET metalloproteins. Thedistinctive feature of our approach was to focus on the enthalpy and entropy changes accompanying protein reduction.These parameters revealed to be informative on the role of first coordination sphere effects, electrostatics at the metalproteininterface, solvent reorganization effects, oxidation state dependent differences in protein dynamics andenthalpy/entropy compensation phenomena as E °' effectors in cytochromes c, Fe-S proteins and blue copper proteins.