DFT study of the mechanism for methane hydroxylation by soluble methane monooxygenase

The exact structure of the active site of intermediate Q, the methane-oxidizing species of soluble methane monooxygenase (sMMO), and the reaction mechanism of Q with methane molecule are still not fully clear. To gain further insights into the structure and reaction mechanism, we study different structure models of Q, including several new models not reported earlier, by performing broken-symmetry density functional theory calculations. Different reaction pathways of methane activated by Q with different structure models, including the radical and non-radical mechanism, are explored to evaluate which structure model is the most possible intermediate and the favorable catalytic mechanism. We expect our results to provide new insights into the catalytic oxidation of methane by sMMO and to promote the design of new catalysts.