Monitoring Conformational Changes in the NDM-1 Metallo-β-lactamaseby 19F NMR Spectroscopy

The New Delhi metallo--lactamase (NDM-1) is involved in the emerging antibiotic resistance problem. Development of metallo--lactamases (MBLs) inhibitors has proven challenging, due to their conformational flexibility. Here we report site-selective labeling of NDM-1 with 1,1,1-trifluoro-3-bromo acetone (BFA), and its use to study binding events and conformational changes upon ligand-metal binding using (FNMR)-F-19 spectroscopy. The results demonstrate different modes of binding of known NDM-1 inhibitors, including L- and D-captopril by monitoring the changing chemical environment of the active-site loop of NDM-1. The method described will be applicable to other MBLs and more generally to monitoring ligand-induced conformational changes.