The Mechanism of Oxygen Cleavage

FIGURE 13. Rate of formation and decay of intermediates P and Q as a function of pH. (From Lee and Lipscomb, 1999). 

Q and that the proton inventory for each reaction is linear. Linear plots generally indicate that a single proton is delivered in a single step during the reaction. Thus, the most direct interpretation of these observations is that the two protons required for the overall stoichiometry are delivered during the P to P and P to Q steps of the reaction cycle. The decay of P shows the same pH dependence as the formation of Q as expected if these are successive steps. In contrast, the decay of Q and the steps leading to P do not exhibit a pH dependence, suggesting that proton is only transferred in the two steps that have been identified. 

FIGURE 14. Hypothetical mechanism for proton delivery during MMO catalysis. (From Lee and Lipscomh, 1999). 

MMO presents a unique opportunity to study monooxygenase chemistry because it forms a series of intermediates that buildup in sufficient 

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