Naslov
Deciphering photodynamics of Firefly Oxyluciferin and its synthetic derivatives to understand the molecular mechanism of Bioluminescence

Autori
Rebarz, Mateusz ; Sliwa, Michel ; Ruckebusch, Cyril ; Maltsev, Oleg ; Hintermann, Lukas ; Ghose, Avisek ; Didier, Pascal ; Kukovec, Boris-Marko ; Naumov, Panče

Vrsta, podvrsta i kategorija rada
Sažeci sa skupova, sažetak, znanstveni

Skup
26th International Conference on Photochemistry (ICP2013), University of Leuven (KU Leuven)

Mjesto i datum
Leuven, Belgija, 21.07.2013. - 26.07.2013

Vrsta sudjelovanja
Poster

Vrsta recenzije
Međunarodna recenzija

Ključne riječi
photodynamics; oxyluciferin; bioluminescence

Sažetak
The mysterious flashes of light communicated by fireflies conceal a rich and exciting solution spectrochemistry that utilize the ground state of the heterocyclic acid D-luciferin as a substrate for enzymatic (protein luciferase) multistep oxidation to generate oxyluciferin in its first excited state. Subsequent deexcitation produces visible photon, which is observed as bioluminescence. Due to alleged instability and luminescence lifetime about few nanoseconds for one single molecule of OxyLH2, the spectrochemistry and structure of OxyLH2 within luciferase in its exited state have still remained unexplored. A triple chemical equilibrium by double deprotonation and keto-enol tautomerism turns this simple molecule into an intricate case where the relative spectral contributions of six chemical species combine over a physiologically relevant pH range, rendering physical isolation and spectral characterization of most of the species unmanageable. To disentangle the individual spectral contributors, we prepared selectively chemically modified oxyluciferin derivatives where some of the chemical equilibria have been intentionally blocked. A multivariate curve resolution– alternating least squares (MCR-ALS) procedure was applied simultaneously to an extensive set of pH-dependent spectroscopic data for oxyluciferin and the target derivatives. The analysis provided, for the first time, the stationary UV-VIS absorption spectra of the pure individual components free of contributions from the other forms, their pH-dependent profiles and distributions, and the most accurate to date values for the three equilibrium constants. To understand dynamics of the emitter we then undertook thoroughly stationary and ultrafast time resolved (fluorescence, absorption, infrared) studies of oxyluciferin and its derivatives in different environment and different state (solution and crystals). The obtained results represent the fundamental benchmark for further in situ spectroscopic studies of the fast processes that occur in the luciferase during the bioluminescence reaction. Moreover, thorough understanding of photochemical properties of oxyluciferin opens interesting perspectives in designing of several irreplaceable tools for microscopic imaging of cells and tissues in vivo.

Izvorni jezik
Engleski

Znanstvena područja
Kemija

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