Upper electron‐excited states in bioluminescence: experimental indication

Abstract

The involvement of upper electron-excited states in bacterial bioluminescence process was studied with excitation energy-accepting molecules. The fluorescent aromatic compounds, anthracene and 1.4-bis(5-phenyloxazol-2-yl)benzene, were chosen. Energies of their lowest excited singlet states are higher than the energy of the analogous state of the bioluminescence emitter; their absorption spectra and bioluminescence do not overlap. Hence, the excitation of these molecules by singlet-singlet energy transfer or by light absorption is excluded. Sensitized fluorescence of these compounds in the bioluminescence systems has been recorded, indicating the activity of upper electron-excited states in the bioluminescent process.

Bioluminescence Assays: Effects of Quinones and Phenols

“…Table 1 reveals that the K values for the quinones are higher than those of the corresponding diphenols in all three bioluminescence systems. The higher inhibition ability of the quinones is due to their chemical activity in the redox processes (Stom, 1977) and to energy withdrawal processes in the bioluminescence processes (Kudryasheva et al, 1991).…”

The mechanism of electronic excitation in the bacterial bioluminescent reaction

“…53 ± 55 In particular, the energy transfer to exogenous molecules introduced in the bioluminescent reaction has been attempted. 53,54 Fluorescent aromatic molecules with energies of the first singlet excited state in the range of 22 000 ± 32 000 cm 71 (i.e., higher than the analogous energy of the emitter molecule) have been used as the exogenous molecules (potential acceptors of excitation energy). Note that the absorption spectra of the chosen molecules did not overlap with the bioluminescence spectrum.…”

The Sensitized Bioluminescence Mechanism of Bacterial Luciferase

“…5, Fluorescence of POPOP . Reprinted with permission from ref . Copyright 2001 John Wiley & Sons, Ltd.…”