Synchrotron X-ray-induced photoreduction of ferric myoglobin nitrite crystals gives the ferrous derivative with retention of the O-bonded nitrite ligand.
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.
Yi
Jun
J
Department of Chemistry and Biochemistry, University of Oklahoma, 620 Parrington Oval, Norman, Oklahoma 73019, USA.
Orville
Allen M
AM
Skinner
John M
JM
Skinner
Michael J
MJ
Richter-Addo
George B
GB
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
D008024:Ligands; D009573:Nitrites; C028048:ferrylmyoglobin; D008786:Metmyoglobin; D007501:Iron