Efficient firefly chemi/bioluminescence: evidence for chemiexcitation resulting from the decomposition of a neutral firefly dioxetanone molecule.

The journal of physical chemistry. A

PubMedID: 23244350

Pinto da Silva L, Santos AJ, Esteves da Silva JC. Efficient firefly chemi/bioluminescence: evidence for chemiexcitation resulting from the decomposition of a neutral firefly dioxetanone molecule. J Phys Chem A. 2013;117(1):94-100.
Both experimental and theoretical methodologies were employed in order to study the possibility of excited state oxyluciferin being formed as the result of the decomposition of a neutral dioxetanone. Excitation measurements in water (at different pH values) and in methanol, along with computational calculations, demonstrated that the hydroxyl-benzothiazole group of firefly dioxetanone and six oxyluciferin analogues is only deprotonated in conditions not in line with the firefly bioluminescence reaction. Thus, a new mechanism involving a neutral firefly dioxetanone must be presented in order to explain the chemiexcitation of oxyluciferin. It was also studied for the first time the interaction between a molecule involved in the bioluminescence reaction (neutral firefly dioxetanone) and the real second conformation of firefly luciferase.