[Mechanism of action of 2,4-dinitrofluorobenzene on bacterial luminescence in vitro]

2,4-Dinitrofluorobenzene (DNFB) changes the parameters of the bioluminescent reaction involving two enzymes, i.e. NADH: FMN-oxidoreductase and luciferase, by decreasing the maximal intensity of luminescence and increasing the time of maximal intensity. Modification of the proteins does not affect the changes of the reaction parameters. The effects of DNFB on each one of the reactions, i.e. reduction of FNM and light emission, were studied. DNFB does not inhibit the reaction of FMN reduction. It was shown that the mechanism of DNFB effect of bioluminescence consists in uncoupling of FMN reduction and light emission due to competitive inhibition of the FMNH2 active center by 2,4-dinitrofluorobenzene.