Reaction Mechanism of FAD-Containing Monooxygenases

Imidazoleacetate and L -lysine monooxygenases from pseudomonads were obtained in crystalline form. Both enzymes were established to contain FAD probably as a sole cofactor. Available evidence indicates that the reaction catalyzed by these enzymes involves the reduction of FAD, the monooxygenation of substrate, and the reoxidation of reduced FAD. The mechanism of activating molecular oxygen by these FAD-containing monooxygenases is discussed.