Spectroscopic investigation of reduced protocatechuate 3,4-dioxygenase: charge-induced alterations in the active site iron coordination environment

Research was conducted to examine the geometric and electronic structure of the reduced iron center. The methodologies used were applied circular dichroism, magnetic circular dichroism, variable-temperature-variable-field molecular circular dichroism, X-ray absorption pre-edge and extended X-ray absorption fine structure spectroscopies. Results indicate that the coordination number increases upon reduction which is attributed to the coordination of a second solvent ligand.