NO and O2 reactivities of synthetic functional models of nitric oxide reductase and cytochrome c oxidase

Abstract

Though nitric oxide reductase (NOR) and cytochrome c oxidase (CcO) have similar active sites, they exhibit quite different functions. While NOR reduces NO to N₂O, CcO reduces O₂ to H₂O. Further, CcO is reversibly inhibited by NO, the substrate for NOR, and NOR is reversibly inhibited by O₂, which is the substrate for CcO. Over the past decade several structural and functional models of these enzymes have been reported. The mimics have been used to understand the reaction mechanism of these enzymes and develop structure function correlations for these active sites. This article summarizes these recent developments with particular stress on the reactivities of functional mimics of CcO with NO and functional mimics of NOR with O₂.