Comparative Study of the Photoprotolytic Reactions of D-Luciferin and Oxyluciferin

• Type: Article in International Scientific Journal
• Date: 2012

Authors

erez, y (Author) Other; presiado, i (Author) Other; gepshtein, r (Author) Other; da silva, lp (Author) Other; da silva, jcge (Author) FCUP; huppert, d (Author) Other

Journal

Title: Journal of Physical Chemistry A

Vol. 116

Pages: 7452-7461

ISSN: 1089-5639

Publisher: American Chemical Society

Indexing

ISI Web of Knowledge - 42 Citations

Scopus - 39 Citations

Scientific classification

FOS: Natural sciences > Chemical sciences

Other information

Authenticus ID: P-002-7Y4

DOI: 10.1021/jp301910p

Abstract (EN): Optical steady-state and time-resolved spectroscopic methods were used to study the photoprotolytic reaction of oxyluciferin, the active bioluminescence chromophore of the firefly's luciferase-catalyzed reaction. We found that like D-luciferin, the substrate of the firefly bioluminescence reaction, oxyluciferin is a photoacid with pK(a)* value of similar to 0.5, whereas the excited-state proton transfer (ESPT) rate coefficient is 2.2 x 10(10) s(-1), which is somewhat slower than that of D-luciferin. The kinetic isotope effect (KIE) on the fluorescence decay of oxyluciferin is 2.5 +/- 0.1, the same value as that of D-luciferin. Both chromophores undergo fluorescence quenching in solutions with a pH value below 3.

Language: English

Type (Professor's evaluation): Scientific

No. of pages: 10