Bioluminescent Nanoluciferase–Furimamide Complex: A Theoretical Study on Different Protonation States

Abstract

Luminescence of furimamide is 150 times brighter than oxidized luciferins in firefly and renilla luciferase. However, we do not have a clear understanding of the structure, function, and dynamic behavior of the nanoluciferase−furimamide complex. Here, for the first time, the absorption and emission properties of eight different possible light emitter forms of furimamide were investigated using the time-dependent density functional theory (TD-DFT) method in the gas phase and aqueous solution. The emission oscillator strengths in the gas phase showed that emission transition may be forbidden for some forms, and fluorescence would not occur. Besides, the charge transfer (CT) as well as the orbitals involved in the transitions were analyzed. Furthermore, molecular docking results showed that furimamide is situated inside the central cavity (β-barrel) of nanoluciferase. Analysis of the trajectory of molecular dynamics (MD) simulations suggested a less compact structure of protein in the presence of furimamide in comparison to its apo form. The quantum mechanical/molecular mechanical (QM/MM) spectroscopic properties of one form in the binding site of nanoluciferase were investigated. The evolution of the excited states (ESs) of furimamide in the binding pocket of the protein confirmed that after photoexcitation and during the relaxation of the system, a crossing point between the first two singlet ESs exists. Thus, the initially populated S2 (a π→π* transition) becomes the first singlet excited state.

Selective Hydrolysis of Ovalbumin by Zr-Based Lacunary Polyoxotungstate in Surfactant Solutions

“…The docking procedure involved an empirical free energy function and the Lamarckian genetic algorithm (LGA). 49 Prior to docking, the protein was prepared by adding hydrogen atoms and Gasteiger charges. Docking grid box dimensions of 70 × 70 × 70 points with a grid spacing of 0.375 Å were defined around the binding site.…”

Tri-part NanoLuc as a new split technology with potential applications in chemical biology: a mini-review

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Chemiluminescence of a Firefly Luciferin Analogue Reveals that Formation of the Key Intermediate Responsible for Excited State Generation Occurs on a Fully Concerted Step

“…Since obtaining and elucidating the structure, as well as achieving the synthesis of the luciferin substrate (LUC, Scheme ) by Bitler et al and White et al in the late 1950s, , extensive experimental and theoretical research has been conducted to understand the mechanism involved in the efficient bioluminescence (BL) of Photinus pyralis. , The study of BL in general benefits from computational simulations of entire systems, − as well as from working with chemiluminescence (CL) reactions that serve as comprehensive models and analogues of BL processes. , …”