Orientational information from unoriented metalloproteins by optically detected electron paramagnetic resonance

Abstract

The electronic structure of metalloproteins can be analysed with optically detected electron paramagnetic resonance (ODEPR). This relatively young technique combines electron paramagnetic resonance (EPR) and magnetic circular dichroism (MCD) with a coherent Raman scattering experiment. It can complement conventional EPR and MCD in the deconvolution and assignment of optical transitions. Information about the relative orientation of optical and magnetic transition dipoles in metalloproteins can be extracted with considerably higher resolution than by alternative techniques such as MCD. We discuss how these features provide information about the environment of metal ions in metalloproteins.