Catalytic Mechanism of Aromatic Nitration by Cytochrome P450 TxtE: Involvement of a Ferric-Peroxynitrite Intermediate.

ABSTRACT: The cytochromes P450 are heme-dependent enzymes that catalyze many vital reaction processes in the human body related to biodegradation and biosynthesis. They typically act as mono-oxygenases; however, the recently discovered P450 subfamily TxtE utilizes O₂ and NO to nitrate aromatic substrates such as L-tryptophan. A direct and selective aromatic nitration reaction may be useful in biotechnology for the synthesis of drugs or small molecules. Details of the catalytic mechanism are unknown, and it has been suggested that the reaction should proceed through either an iron(III)-superoxo or an iron(II)-nitrosyl intermediate. To resolve this controversy, we used stopped-flow kinetics to provide evidence for a catalytic cycle where dioxygen binds prior to NO to generate an active iron

SUBMITTER: Louka S 

PROVIDER: S-EPMC7586343 | biostudies-literature | 2020 Sep

REPOSITORIES: biostudies-literature