Fluorinated Phosphoadenosine 5′-Phosphosulfate Analogues for Continuous Sulfotransferase Activity Monitoring and Inhibitor Screening by 19F NMR Spectroscopy

Sulfotransferases (STs) are ubiquitous enzymes that participate in a vast number of biological processes involving sulfuryl group (SO3) transfer. 3'-phosphoadenosine 5'-phosphosulfate (PAPS) is the universal ST cofactor, serving as the active sulfate source in cells. Herein, we report the synthesis of three fluorinated PAPS analogues that bear fluorine or trifluoromethyl substituents at the C2 or C8 positions of adenine and their evaluation as substitute cofactors that enable ST activity to be quantified and real-time-monitored by fluorine-19 nuclear magnetic resonance (19F NMR) spectroscopy. Using plant AtSOT18 and human SULT1A3 as two model enzymes, we reveal that the fluorinated PAPS analogues show complementary properties with regard to recognition by enzymes and the working F-19 NMR pH range and are attractive versatile tools for studying STs. Finally, we developed an F-19 NMR assay for screening potential inhibitors against SULT1A3, thereby highlighting the possible use of fluorinated PAPS analogues for the discovery of drugs for ST-related diseases.

Automated summary

In this study, we synthesized three fluorinated PAPS analogues and evaluated their performance as ST cofactors using fluorine-19 nuclear magnetic resonance (19F NMR) spectroscopy. These analogues showed complementary properties in enzyme recognition and working pH range, making them attractive tools for studying STs. Additionally, we developed an F-19 NMR assay for screening potential inhibitors against SULT1A3, highlighting the potential use of fluorinated PAPS analogues for drug discovery in ST-related diseases.