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Antibiotic resistance is a growing global health threat that risks the lives of millions. Among the resistance mechanisms, that mediated by metallo-beta-lactamases is of particular concern as these bacterial enzymes dismantle most beta-lactam antibiotics, which are our widest applied and cheapest to produce antibiotic agents. So far, no clinically applicable metallo-beta-lactamase inhibitors are available. Aiming to adapt to structural variations, we introduce the inhibitor concept: dynamically chiral phosphonic acids. We demonstrate that they are straightforward to synthesize, penetrate bacterial membranes, inhibit the metallo-beta-lactamase enzymes NDM-1, VIM-2 and GIM-1, and are non-toxic to human cells. Mimicking the transition state of beta-lactam hydrolysis, they target the Zn ions of the metallo-beta-lactamase active site. As a unique feature, both of their stereoisomers bind metallo-beta-lactamases, which provides them unparalleled adaptability to the structural diversity of these enzymes, and may allow them to hamper bacteria's ability for resistance development.

The upswing of antibiotic resistance is an escalating threat to human health. Resistance mediated by bacterial metallo-β-lactamases is of particular concern as these enzymes degrade β-lactams, our most frequently prescribed class of antibiotics. Inhibition of metallo-β-lactamases could allow the continued use of existing β-lactam antibiotics, such as penicillins, cephalosporins and carbapenems, whose applicability is becoming ever more limited. The design, synthesis, and NDM-1, VIM-2, and GIM-1 inhibitory activities (IC50 4.1–506 μM) of a series of novel non-cytotoxic α-aminophosphonate-based inhibitor candidates are presented herein. We disclose the solution NMR spectroscopic and computational investigation of their NDM-1 and VIM-2 binding sites and binding modes. Whereas the binding modes of the inhibitors are similar, VIM-2 showed a somewhat higher conformational flexibility, and complexed a larger number of inhibitor candidates in more varying binding modes than NDM-1. Phosphonate-type inhibitors may be potential candidates for development into therapeutics to combat metallo-β-lactamase resistant bacteria.