Abstracts

Bioluminescence, the process of emitting visible cold light by living organisms, is catalyzed by an enzyme generically called luciferase, acting together with a substrate known as luciferin. This biological phenomenon, which illuminates both marine abysses and terrestrial habitats, has captured scientific and public interest due to its features and its potential biotechnological applications. Despite its wide occurrence in nature, many aspects of bioluminescent systems remain unknown, particularly in certain families such as Keroplatidae (Diptera), in which the luciferase enzyme has not yet been identified. Within this family, the subfamily Keropatinae arouses special interest, presenting two recently discovered substrates that contribute to the bioluminescent process: riboflavin and 3-hydroxykynurenic acid (3-HOKA).The investigation of these biochemical components unveils fresh perspectives for grasping the variety of bioluminescence in the world. In an effort to shed light on the processes that underpin bioluminescence within the Keropatinae subfamily, we conducted a bioprospecting study employing the technique of inverse virtual screening (IVS).This method allowed the modeling of proteins expressed in the transcript of Orfelia fultoni, a member of this subfamily, followed by molecular docking with riboflavin and 3-HOKA. Through this approach, we identified 2,868 structures with strong interactions, culminating in the selection of 11 candidate proteins that may be intricately involved in the bioluminescent process of this species. Among the identified proteins, NADPH-Cytochrome P450 Reductase stands out for its reducing function and its strong binding energy with riboflavin, suggesting a crucial role in riboflavin reduction, which could sustain the light emission of these organisms, as observed in nature, for extended periods. Furthermore, the discovery of hexamerin-like enzymes and the exploration of their spatial configurations led us to identify two potential monomers. These monomers are candidates to form a trimeric structure that interacts efficiently with both riboflavin and 3-hydroxykynurenic acid, offering new perspectives on the molecular architecture of bioluminescence in O. fultoni. Therefore, we propose potential mechanisms involving these proteins in the generation of bioluminescent light in O. fultoni, emphasizing the importance of future in vitro investigations to deepen our understanding of these biological processes. Despite the limitations associated with virtual screening, this study represents a significant advancement in understanding bioluminescence in Diptera, contributing to both evolutionary biology and the development of biotechnological applications.