1. Chemical Modification of the Nitrogenase MoFe-protein with Photo- and Redox-Active Groups
F. Akif Tezcan, Department of Chemistry and Biochemistry, UCSD, La Jolla , CA 92093
Mechanistic details of how nitrogenase accomplishes the conversion of dinitrogen into ammonia still remain a mystery after decades of extensive research. Reduction of the nitrogenase active site metal cluster, the iron–molybdenum cofactor (FeMoco), is postulated to be required for substrate binding and has only been achieved under turnover conditions in solution. We aim here to develop photo- and electrochemical methods to activate FeMoco for substrate activation.
We have succeeded in labeling the molydenum-iron protein (which houses FeMoco) with ruthenium-based photo-active groups and methyl viologen-based redox-active groups, and determined that these groups are located on the α-subunit of the protein as desired.
We are now gearing up to determine whether the MV- or Ru-derivatized molybdenum-iron protein can be activated for substrate reduction by light or electrochemical energy.