Esra Balıkçı, Anne-Sophie M C Marques, Ludwig G Bauer, Raina Seupel, James Bennett, Brigitt Raux, Karly Buchan, Klemensas Simelis, Usha Singh, Catherine Rogers, Jennifer Ward, Carol Cheng, Tamas Szommer, Kira Schützenhofer, Jonathan M Elkins, David L Sloman, Ivan Ahel, Oleg Fedorov, Paul E Brennan, Kilian V M Huber
Cofactor mimicry represents an attractive strategy for the development of enzyme inhibitors but can lead to off-target effects due to the evolutionary conservation of binding sites across the proteome. Here, we uncover the ADP-ribose (ADPr) hydrolase NUDT5 as an unexpected, noncovalent, off-target of clinical BTK inhibitors. Using a combination of biochemical, biophysical, and intact cell NanoBRET assays as well as X-ray crystallography, we confirm catalytic inhibition and cellular target engagement of NUDT5 and reveal an unusual binding mode that is independent of the reactive acrylamide warhead...
April 18, 2024: Journal of Medicinal Chemistry