Intermediates in the bacterial luciferase reaction

Rapid formation of an unstable, intermediary state of an enzyme complex, which is obligatory in the bacterial luciferase reaction, was observed on aerobic oxidation of the luciferase-FMNH₂ complex. The rate of decay of this intermediate in the absence of aldehyde was measured. The value obtained coincided with that estimated from the decay of the peak intensity of luminescence observed on addition of aldehyde at intervals after mixing the luciferase-FMNH₂ complex with O₂. A sequential mechanism of the reaction of bacterial luciferase is discussed.