Enhancement of light emission in the bacterial luciferase reaction by H2O2

In the bacterial luciferase reaction, light emission is due to the mixed function oxidation of FMNH2 and long chain aldehydes, which leads to the formation of an electronically excited product species, postulated to be luciferase-bound 4a-hydroxy flavin. In the present work it was found that H2O2 stimulates an additional and kinetically distinct luminescence. The stimulation is more apparent in reactions inhibited by long chain alcohols, and the H2O2 is effective even if added secondarily. The stimulation requires H2O2 only at the outset; its subsequent destruction by catalase does not diminish the response, appreciably.