Comparative theoretical study of the binding of luciferyl-adenylate and dehydroluciferyl-adenylate to firefly luciferase

► Firefly flash-profile was theoretical studied for the first time. ► Electrostatic interactions were suggested to control the binding of adenylates. ► LH2-AMP and L-AMP appear to have similar affinity for luciferase. ► Amino-acid residues that impair the binding of LH2-AMP were defined. ► Both d-LH2-AMP and d-LH2-AMP adopt the l-orientation in the active site.