Iyamu, Iredia D.Vilseck, Jonah Z.Yadav, RaviNoinaj, NicholasHuang, Rong2022-03-102022-03-102022Iyamu, I. D., Vilseck, J. Z., Yadav, R., Noinaj, N., & Huang, R. (2022). Exploring Unconventional SAM Analogues To Build Cell-Potent Bisubstrate Inhibitors for Nicotinamide N-Methyltransferase. Angewandte Chemie. https://doi.org/10.1002/ange.2021148130044-8249, 1521-3757https://hdl.handle.net/1805/28134Nicotinamide N-methyltransferase (NNMT) methylates nicotinamide and has been associated with various diseases. Herein, we report the first cell-potent NNMT bisubstrate inhibitor II399, demonstrating a Ki of 5.9 nM in a biochemical assay and a cellular IC50value of 1.9µM. The inhibition mechanism and cocrystal structure confirmed II399 engages both the substrate and cofactor binding pockets. Computational modeling and binding data reveal a balancing act between enthalpic and entropic components that lead to II399’s low nM binding affinity. Notably, II399 is 1,000-fold more selective for NNMT than closely related methyltransferases. We expect that II399would serve as a valuable probe to elucidate NNMT biology. Furthermore, this strategy provides the first case of introducing unconventional SAM mimics, which can be adopted to develop cell-potent inhibitors for other SAM-dependent methyltransferases.enPublisher Policyanaloguesanaloguesbisubstrateenzymescell-potentinhibitorsbisubstrateinhibitorsSAMArticle