Electron Paramagnetic Resonance Facility
in Life Sciences at the Chemistry-Biology interface

Electron Paramagnetic Resonance (EPR), or Electron Spin Resonance (ESR), is a central technique for characterizing paramagnetic species, i.e. molecules bearing unpaired electrons. In the field of Life Sciences in particular in structural biology, EPR has gained increasing interests in the last two decades thanks to both technological and methodological developments. EPR is particularly well suited for molecular analysis of biological systems, such as proteins. In metalloenzymes, in which the metal is central for the catalysis, EPR is the technique of choice to investigate the function and decipher the catalytic mechanisms of these biomolecules. In the absence of endogenous paramagnetic species, another way of using EPR spectroscopy consists in grafting exogenous paramagnetic centers (spin labels) at selected sites on biomolecules. This approach opens up the possibility to explore protein dynamics and to measure inter-label distances in the nanometer range, providing crucial information on structural transitions and intermolecular interactions in solution as well as directly inside cells.