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

• Tipo: Artigo em Revista Científica Internacional
• Data: 2012

Autores

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

Revista

Título: Journal of Physical Chemistry A

Vol. 116

Páginas: 7452-7461

ISSN: 1089-5639

Editora: American Chemical Society

Indexação

ISI Web of Knowledge - 42 Citações

Scopus - 39 Citações

Classificação Científica

FOS: Ciências exactas e naturais > Química

Outras Informações

ID Authenticus: 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.

Idioma: Inglês

Tipo (Avaliação Docente): Científica

Nº de páginas: 10