Ammonia monooxygenase-mediated transformation of 17α-ethinylestradiol: Underlying molecular mechanism

Lili Wang; Anjie Li

doi:10.1016/j.envres.2023.116930

Ammonia monooxygenase-mediated transformation of 17α-ethinylestradiol: Underlying molecular mechanism

Environ Res. 2023 Nov 15;237(Pt 1):116930. doi: 10.1016/j.envres.2023.116930. Epub 2023 Aug 19.

Authors

Lili Wang¹, Anjie Li²

Affiliations

¹ Key Laboratory of Water and Sediment Sciences of Ministry of Education, State Key Laboratory of Water Environment Simulation, School of Environment, Beijing Normal University, Beijing, 100875, China; Laboratory of Environmental Protection in Water Transport Engineering, Tianjin Research Institute of Water Transport Engineering, Tanggu, Tianjin, 300456, China.
² Key Laboratory of Water and Sediment Sciences of Ministry of Education, State Key Laboratory of Water Environment Simulation, School of Environment, Beijing Normal University, Beijing, 100875, China. Electronic address: liaj@bnu.edu.cn.

PMID: 37604224
DOI: 10.1016/j.envres.2023.116930

Abstract

17α-ethinylestradiol (EE2) has received increasing attention as an emerging and difficult-to-remove emerging contaminant in recent years. Ammonia-oxidizing bacteria (AOB) have been reported to be effective in EE2 removal, and ammonia monooxygenase (AMO) is considered as the primary enzyme for EE2 removal. However, the molecular mechanism underlying the transformation of EE2 by AOB and AMO is still unclear. This study investigated the molecular mechanism of EE2 degradation using a combination of experimental and computational simulation methods. The results revealed that ammonia nitrogen was essential for the co-metabolism of EE2 by AOB, and that NH₃ bound with Cu_C (one active site of AMO) to induce a conformational change in AMO, allowing EE2 to bind with the other active site (Cu_B), and then EE2 underwent biological transformation. These results provide a theoretical basis and a novel research perspective on the removal of ammonia nitrogen and emerging contaminants (e.g., EE2) in wastewater treatment.

Keywords: Ammonia monooxygenase; Co-metabolism; EE2 transformation; Molecular docking; Molecular dynamics simulation.