Redox compounds influence on the NAD(P)H:FMN-oxidoreductase-luciferase bioluminescent system.

A review of the mechanisms of the exogenous redox compounds influence on the bacterial coupled enzyme system: NAD(P)H:FMN-oxidoreductase-luciferase has been done. A series of quinones has been used as model organic oxidants. The three mechanisms of the quinones' effects on bioluminescence were suggested: (1) inhibition of the NADH-dependent redox reactions; (2) interactions between the compounds and the enzymes of the coupled enzyme system; and (3) intermolecular energy migration. The correlation between the kinetic parameters of bioluminescence and the standard redox potential of the quinones proved that the inhibition of redox reactions was the key mechanism by which the quinones decrease the light emission intensity. The changes in the fluorescence anisotropy decay of the endogenous flavin of the enzyme preparations showed the direct interaction between quinones and enzymes. It has been demonstrated that the intermolecular energy migration mechanism played a minor role in the effect of quinones on the bioluminescence. A comparative analysis of the effect of quinones, phenols and inorganic redox compounds on bioluminescent coupled enzyme systems has been carried out.