QM/MM Investigation of the Spectroscopic Properties of the Fluorophore of Bacterial Luciferase

We employ replica-exchange molecular dynamics (REMD) and a hybrid ab initio multiconfigurational quantum mechanics/molecular mechanics (QM/MM) approach to model the absorption and fluorescence properties of bacterial luciferin-luciferase. Specifically, we employ complete active space perturbation theory (CASPT2) and study the effect of active space, basis set, and IPEA shift on the computed energies. We discuss the effect of the protein environment on the fluorophore's excited-state potential energy surface and the role that the protein plays in enhancing the fluorescence quantum yield in bacterial bioluminescence.

Automated summary

In this study, replica-exchange molecular dynamics and a hybrid ab initio multiconfigurational quantum mechanics/molecular mechanics approach were used to model the absorption and fluorescence properties of bacterial luciferin-luciferase. The effect of the protein environment on the fluorophore's excited-state potential energy surface was discussed, as well as the role of the protein in enhancing the fluorescence quantum yield in bacterial bioluminescence.