Methane monooxygenase and ammonia monooxygenase (MMO and AMO) (MMO/AMO)

Methane monooxygenase (MMO) and ammonia monooxygenase (AMO) are metalloenzymes essential for the metabolic processes of methanotrophic and nitrifying bacteria and archaea (Lawton & Rosenzweig, 2016). MMO facilitates the conversion of methane to methanol, playing a pivotal role in the global carbon cycle and the mitigation of methane emissions (UniProt P11984). AMO performs the initial, rate-limiting step of nitrification by oxidizing ammonia to hydroxylamine, which is central to the nitrogen cycle (Walker et al., 2010). These enzymes are structurally similar, particularly the membrane-bound particulate MMO (pMMO) and AMO, which both utilize copper centers for catalysis (PubMed 30655386). While they are not targets for human disease therapy, they are significant targets in agricultural chemistry; AMO inhibitors like Nitrapyrin are used to prevent nitrogen leaching and nitrous oxide production in soil (PubChem CID 4544). Their study is also relevant for bioremediation, as they can co-metabolize various environmental pollutants such as trichloroethylene (Wikipedia, "Methane monooxygenase").

Other names

pMMOsMMOAMOMethane hydroxylaseAmmonia hydroxylaseCopper-dependent membrane monooxygenaseParticulate methane monooxygenaseSoluble methane monooxygenase

Inhibition of the enzymatic oxidation of methane or ammonia, often through competitive binding at the copper-containing active site or suicide inhibition via covalent modification by reactive intermediates (PubChem CID 4544; PubMed 10411744).