The oxygenated bacterial luciferase-flavin intermediate. Reaction products via the light and dark pathways

The identity and stoichiometry of the reaction products of the oxygenated reduced flavin bacterial luciferase intermediate isolated by Sephadex chromatography at low temperature have been determined under two conditions, allowing the reaction to go to completion by warming either in the presence or absence of long chain aliphatic aldehyde. In the latter case, very little bioluminescence occurs, and 1 mol each of H2O2 and FMN is produced per mol of enzyme intermediate. In the presence of aldehyde, the formation of an aldehyde-enzyme intermediate complex can be detected by optical absorption spectroscopy at -30 degrees; upon warming, bioluminescence with high quantum yield occurs with the formation of 1 mol of FMN but no H2O2.