The Inhibition of Bacterial Luciferase by Mixed Function Oxidase Inhibitors

On the hypothesis that bacterial luciferase may be classed as a mixed function oxidase, compounds reported to be specific inhibitors for such enzymes were tested. Inhibitors designated as SKF (2-diethylaminoethyl-2,2-diphenyl valerate), DPDA (N,N-diethyl-2,4-dichloro(6-phenylphenoxy)-ethylamine), and DPEA (2,3-dichloro(6-phenylphenoxy)ethylamine) were effective in blocking the in vitro reaction of pure luciferase at inhibitor concentrations between 10-5 and 10-4 m. The mode of action of the two different types of compounds has been found to be distinctly different. One (SKF) interferes with the reaction of one of the substrates, namely FMNH2, while the other (DPEA) blocks the site for aldehyde, the second substrate. Both compounds are effective inhibitors of bacterial growth and luminescence, affecting both functions in similar although not identical degrees.