The Sensitized Bioluminescence Mechanism of Bacterial Luciferase

Abstract

After more than one‐half century of investigations, the mechanism of bioluminescence from the FMNH2 assisted oxygen oxidation of an aliphatic aldehyde on bacterial luciferase continues to resist elucidation. There are many types of luciferase from species of bioluminescent bacteria originating from both marine and terrestrial habitats. The luciferases all have close sequence homology, and in vitro, a highly efficient light generation is obtained from these natural metabolites as substrates. Sufficient exothermicity equivalent to the energy of a blue photon is available in the chemical oxidation of the aldehyde to the corresponding carboxylic acid, and a luciferase‐bound FMNH‐OOH is a key player. A high energy species, the source of the exothermicity, is unknown except that it is not a luciferin cyclic peroxide, a dioxetanone, as identified in the pathway of the firefly and the marine bioluminescence systems. Besides these natural substrates, variable bioluminescence properties are found using other reactants such as flavin analogs or aldehydes, but results also depend on the luciferase type. Some rationalization of the mechanism has resulted from spatial structure determination, NMR of intermediates and dynamic optical spectroscopy. The overall light path appears to fall into the sensitized class of chemiluminescence mechanism, distinct from the dioxetanone types.

Toxicity and Antioxidant Activity of Fullerenol C60,70 with Low Number of Oxygen Substituents

“…It is known that one of the intermediates of the bioluminescent luciferase's reaction (reaction 2, Section 3.2. ), flavin peroxy-semiacetal [63,64], is a peroxide that is categorized as a ROS. Hence, the decrease in ROS content at high fullerene concentrations can account for the inhibition of the bioluminescent reaction (reaction 2, Section 3.2.).…”

“…Therefore, the previous results on the suppression of antiviral activity [25] and the decrease in biolumines- The physicochemical mechanism of fullerenol's toxic influence on the enzymatic assay system is likely due to its ability to neutralize free radicals [33], including peroxide radicals. It is known that one of the intermediates of the bioluminescent luciferase's reaction (reaction 2, Section 3.2), flavin peroxy-semiacetal [63,64], is a peroxide that is categorized as a ROS. Hence, the decrease in ROS content at high fullerene concentrations can account for the inhibition of the bioluminescent reaction (reaction 2, Section 3.2).…”

Deazaflavin reductive photocatalysis involves excited semiquinone radicals

“…Fl cofactors in their fully reduced form participate in photo-induced electron transfer (PET) reactions in DNA photolyases repairing pyrimidine dimers formed upon exposure to ultraviolet (UV) light 23,24 . Fls in their oxidised form are responsible for bacterial bioluminescence 25 or perform various functions in photoreceptors 7,[26][27][28] . dFl dF 0 in its oxidised form serves as a light-harvesting antenna in photolyases 29 .…”

A Miniaturized Microbe-Silicon-Chip Based on Bioluminescent Engineered Escherichia coli for the Evaluation of Water Quality and Safety

“…The analyte binds the MerR protein in the cell (red in the figure), causing it to release its repression on the promoter, which triggered the expression of the luciferase and its substrate (blue in the figure). The enzyme then catalyzed the long-chain aldehyde oxidation to a carboxylic acid and released energy as photons [ 40 ]. This gave a 490 nm blue-green light, used as output for the optical detection and quantification, whose intensity was related to the mercury amount in the water sample in a dose-dependent manner.…”