title: Synchrotron X-ray-induced photoreduction of ferric myoglobin nitrite crystals gives the ferrous derivative with retention of the O-bonded nitrite ligand.
abstract: Exposure of a single crystal of the nitrite adduct of ferric myoglobin (Mb) at 100 K to high-intensity synchrotron X-ray radiation resulted in changes in the UV-vis spectrum that can be attributed to reduction of the ferric compound to the ferrous derivative. We employed correlated single-crystal spectroscopy with crystallography to further characterize this photoproduct. The 1.55 A resolution crystal structure of the photoproduct reveals retention of the O-binding mode for binding of nitrite to the iron center. The data are consistent with cryogenic generation and trapping, at 100 K, of a ferrous d(6) Mb(II)(ONO)* complex by photoreduction of the ferric precursor crystals using high-intensity X-ray radiation.
authors.affiliation: Department of Chemistry and Biochemistry, University of Oklahoma, 620 Parrington Oval, Norman, Oklahoma 73019, USA.
authors.forename: Jun
authors.initials: J
authors.lastname: Yi
authors.forename: Allen M
authors.initials: AM
authors.lastname: Orville
authors.forename: John M
authors.initials: JM
authors.lastname: Skinner
authors.forename: Michael J
authors.initials: MJ
authors.lastname: Skinner
authors.forename: George B
authors.initials: GB
authors.lastname: Richter-Addo
mesh_terms: D018360:Crystallography, X-Ray / Q000379:methods; D007501:Iron / Q000737:chemistry*; D008024:Ligands; D008786:Metmyoglobin / Q000737:chemistry*; D009573:Nitrites / Q000737:chemistry*; D011487:Protein Conformation; D017356:Synchrotrons
chemical_list: D008024:Ligands; D009573:Nitrites; C028048:ferrylmyoglobin; D008786:Metmyoglobin; D007501:Iron