SOR  
    Electron density distribution and geometry in the active site of mono-iron, non-hemic proteins   can be characterized from the RR spectra.
   Superoxide reductases are enzymes involved in combating oxidative stress by depleting superoxide levels in anaerobic and microaerobic prokaryotes. The RR spectra of SORs from different sources and especially designed mutant proteins can indicate the features responsible for different catalytic and ligand binding properties in these enzymes.