Additionally, to our knowledge this is the first pulse dipolar EPR methodology to extract cooperativity and 𝐾 𝐷 parameters by global fitting of nitroxide-nitroxide DEER and Cu II -nitroxide RIDME modulation depths. Results also showcase the robustness and accuracy of PDS in monitoring equilibria processes and to detect variations of cooperativity mode while changing buffer conditions (Wort et. al., in preparation). Finally, this methodology can be easily complemented by other PDS measurements (for instance, by Cu II -Cu