Bioluminescence emission from the reaction of luciferase-flavin mononucleotide radical with O2-..
The blue neutral luciferase flavin radical has been shown not to be in a catalytically significant equilibrium with species leading to emission of light [Kurfürst, M., Ghisla, S., Presswood, R., & Hastings, J. W. (1982) Eur. J. Biochem. 123, 355-361]. It is shown here that this radical can nevertheless react with O2-. to form a species that is competent in light emission. From its properties, the species formed is deduced to be luciferase-FMNH 4a-hydroperoxide, a key intermediate in the normal luciferase reaction. Although it is concluded that this intermediate can undergo a reversible homolytic dissociation to yield free superoxide and the corresponding luciferase radical, the slowness of these steps precludes a catalytic significance for these pathways in the normal bioluminescent reaction.
D005486:Flavin Mononucleotide / Q000378:metabolism*; D005609:Free Radicals; D008156:Luciferases / Q000378:metabolism*; D008163:Luminescent Measurements; D010100:Oxygen / Q000378:metabolism*; D014733:Vibrio / Q000201:enzymology
D005609:Free Radicals; D005486:Flavin Mononucleotide; D008156:Luciferases; D010100:Oxygen