Light-Activated Electron Transfer and Catalytic Mechanism of Carnitine Oxidation by Rieske-Type Oxygenase from Human Microbiota.

ABSTRACT: Oxidation of quaternary ammonium substrate, carnitine by non-heme iron containing Acinetobacter baumannii (Ab) oxygenase CntA/reductase CntB is implicated in the onset of human cardiovascular disease. Herein, we develop a blue-light (365 nm) activation of NADH coupled to electron paramagnetic resonance (EPR) measurements to study electron transfer from the excited state of NADH to the oxidized, Rieske-type, [2Fe-2S]²⁺ cluster in the AbCntA oxygenase domain with and without the substrate, carnitine. Further electron transfer from one-electron reduced, Rieske-type [2Fe-2S]¹⁺ center in AbCntA-WT to the mono-nuclear, non-heme iron center through the bridging glutamate E205 and subsequent catalysis occurs only in the presence of carnitine. The electron transfer process in

SUBMITTER: Shanmugam M 

PROVIDER: S-EPMC7986066 | biostudies-literature | 2021 Feb

REPOSITORIES: biostudies-literature