1.14.14.3 1-deaza-FMNH2 can replace FMNH2 348552 1.14.14.3 2',3'-Diacetyl-FMNH2 as substitute for FMNH2 348574 1.14.14.3 2-Thio-FMNH2 as substitute for FMNH2 348574 1.14.14.3 3-carboxymethyl-FMNH2 as substitute for FMNH2 348574 1.14.14.3 4a-hydroxy-4a,5-dihydroriboflavin-5'-phosphate model bioluminescence emitter molecule, binding and fluorescence quantum yield studies, complexed with the enzyme in a 1:1 molcular ratio 658050 1.14.14.3 FMN - 702318, 704579 1.14.14.3 FMN dependent on 727031 1.14.14.3 FMN potassium iodide quenches the fluorescence of FMN 676321 1.14.14.3 FMN presence of two discrete and well-separated intensity decay lifetimes (ca. 1 and 5 ns) and intensity decay heterogeneity, of the neat sample suggests that the endogenous FMN senses a heterogeneous fluorescence quenching microenvironment at the active site of the luciferase. Free FMN in solution (isotropic environment), exhibits a single decay lifetime (5 ns), i.e., no intensity decay heterogeneity. Intensity decay heterogeneity of endogenous FMN is largely preserved in the presence of quinone. Averaged rotational rate of FMN increases with the increasing hydrophobicity of the quinone 702699 1.14.14.3 FMN the luminescence reaction is initiated by the reduction of FMN 702496