The production of nitrous oxide by the heme/nonheme diiron center of engineered myoglobins (Fe(B)Mbs) proceeds through a trans-iron-nitrosyl dimer.

ABSTRACT: Denitrifying NO reductases are transmembrane protein complexes that are evolutionarily related to heme/copper terminal oxidases. They utilize a heme/nonheme diiron center to reduce two NO molecules to N2O. Engineering a nonheme Fe(B) site within the heme distal pocket of sperm whale myoglobin has offered well-defined diiron clusters for the investigation of the mechanism of NO reduction in these unique active sites. In this study, we use FTIR spectroscopy to monitor the production of N2O in solution and to show that the presence of a distal Fe(B)(II) is not sufficient to produce the expected product. However, the addition of a glutamate side chain peripheral to the diiron site allows for 50% of a productive single-turnover reaction. Unproductive reactions are characterized by resonance Ram

SUBMITTER: Matsumura H 

PROVIDER: S-EPMC4004238 | biostudies-literature | 2014 Feb

REPOSITORIES: biostudies-literature