Oxidative dehalogenation and denitration by a flavin-dependent monooxygenase is controlled by substrate deprotonation.

ABSTRACT: Enzymes that are capable of detoxifying halogenated phenols (HPs) and nitrophenols (NPs) are valuable for bioremediation and waste biorefining. HadA monooxygenase was found to perform dual functions of oxidative dehalogenation (hydroxylation plus halide elimination) and denitration (hydroxylation plus nitro elimination). Rate constants associated with individual steps of HadA reactions with phenol, halogenated phenols and nitrophenols were measured using combined transient kinetic approaches of stopped-flow absorbance/fluorescence and rapid-quench flow techniques. Density functional theory was used to calculate the thermodynamic and electronic parameters associated with hydroxylation and group elimination steps. These parameters were correlated with the rate constants of hydroxylation, gro

SUBMITTER: Pimviriyakul P 

PROVIDER: S-EPMC6180312 | biostudies-literature | 2018 Oct

REPOSITORIES: biostudies-literature