Study on the Effects of Intermolecular Interactions on Firefly Multicolor Bioluminescence

Abstract

Firefly luciferase exhibits a color-tuning mechanism based on pH-induced changes in the structure of the active site. These changes increase the polarity of the active site, and thus modulate the intermolecular interactions between the light emitter and active site molecules. In this study, the effects exerted by adenosine monophosphate (AMP), water molecules, and amino acids of Luciola cruciata luciferase active site on the emission wavelength of oxyluciferin were assessed by TD-DFT calculations. The redshift results mainly from decreased interaction of oxyluciferin with AMP and increased interaction of the emitter with a water molecule and Phe249. Breaking of a hydrogen bond between the benzothiazole oxygen atom with formation of a similar bond to the thiazolone oxygen atom is also instrumental.

The Spectral–Structural Relationship of a Series of Oxyluciferin Derivatives

“…The structure of the 2D1R was first published by Nakatsu et al, [15] where active residues of the luciferase were determined. Recently, Esteves da Silva et al [29] investigated the effects of amino acids in the luciferase active site on the emission wavelength of oxyluciferin by using time-dependent density functional theory (TDDFT). They argued that these nine amino acids residues are the most important contributors to shifts in the emission wavelengths.…”

Firefly Chemiluminescence and Bioluminescence: Efficient Generation of Excited States

“…[39] However, these studies are theoretical, and no conclusive experimental evidence was presented so far that validates this con-clusion. [4,[38][39][40][41][42][43][44][45][46][47][48][49] These changes increase the polarity of the active site with decreasing pH and affect the electrostatic, p-p stacking, and hydrogen-bonding interactions formed between the bioluminophore and active-site molecules. [17][18][19][20] Luc is a pH-sensitive enzyme, and at acid pH the emission wavelength is shifted to the red region of the visible spectrum ( % 620 nm).…”

Effect of very high magnetic field on the optical properties of firefly light emitter oxyluciferin

“…And thirdly, the applied magnetic field may induce changes to the luciferin-luciferase chemical reaction, such as the balance between cage and escape products and the yield of certain intermediate molecules. Finally, another possibility is that the magnetic field used by Iwasaka et al could have affected the intermolecular interactions (as hydrogen bonding, electrostatic, π-π stacking) between oxyluciferin and the active site of luciferase [38][39][40][41][42] and thus causing spectral changes. Nonetheless, what we could conclude from our data is, that the spectral changes observed by Iwasaka et al, if true, are related neither to the light emitter oxyluciferin nor to its intrinsic energy states.…”