Enantiodifferentiation of ketoprofen by Japanese firefly luciferase from Luciola lateralis

Recently, we found that firefly luciferase exhibited (R)-enantioselective thioesterification activity toward 2-arylpropanoic acids. In the case of Japanese firefly luciferase from Luciola lateralis (LUC-H), the E-value for ketoprofen was approximately 20. In this study, we used a spectrophotometric method to measure the catalytic activity of LUC-H. Using this method allowed us to judge the reaction efficiency easily. Our results confirmed that LUC-H exhibits enantioselective thioesterification activity toward a series of 2-arylpropanoic acids. The highest activity was observed with ketoprofen. We also observed high enzymatic activity of LUC-H toward long-chain fatty acids. These results were reasonable because LUC-H is homologous with long-chain acyl-CoA synthetase. To obtain further information about the enantiodifferentiation mechanism of the LUC-H catalyzed thioesterification of ketoprofen, we determined the kinetic parameters of the reaction relative to each of its three substrates: ketoprofen, ATP, and coenzyme A (CoASH). We found that whereas the affinities of each compound are not affected by the chirality of ketoprofen, enantiodifferentiation is achieved by a chirality-dependent difference in the kcat parameter.

Graphical abstractA Japanese firefly luciferase from Luciola lateralis (LUC-H) has an enantioselective acyl-CoA synthetase activity toward ketoprofen. In this article, we determined the catalytic activity and kinetic parameters to estimate the enantiodifferentiation mechanism of LUC-H catalyzed thioester formation.Figure optionsDownload full-size imageDownload as PowerPoint slideResearch highlights► Firefly luciferase, LUC-H, can catalyze the enantioselective thioesterification of 2-aryl propanoic acids. ► Catalytic activity and kinetic parameters of LUC-H were determined. ► The enantiodifferentiation event occurs after the binding of either enantiomer of ketoprofen.