Raman-assisted crystallography reveals end-on peroxide intermediates in   a nonheme iron enzyme
  Iron-peroxide intermediates are central in the reaction cycle of many iron-containing biomolecules. We trapped iron(III)-(hydro)peroxo species in crystals of superoxide reductase (SOR), a nonheme mononuclear iron enzyme that scavenges superoxide radicals. X-ray diffraction data at 1.95 angstrom resolution and Raman spectra recorded in crystallo revealed iron-(hydro)peroxo intermediates with the (hydro)peroxo group bound end-on. The dynamic SOR active site promotes the formation of transient hydrogen bond networks, which presumably assist the cleavage of the iron-oxygen bond in order to release the reaction product, hydrogen peroxide. 
Gergely Katona (IBS - UMR 5075), Philippe Carpentier (IBS - UMR 5075),   Vincent Nivi\`ere (LCBM - UMR 5249), Patricia Amara...
q-bio.BM