Target-based whole-cell screening by ¹H NMR spectroscopy

Area of Science:

• Biochemistry
• Microbiology
• Chemical Biology

Background:

• Traditional drug screening methods include phenotypic and target-based screening.
• New Delhi metallo-β-lactamase subclass 1 (NDM-1) is a critical target for developing new antibiotics.
• Real-time monitoring of meropenem hydrolysis in Escherichia coli expressing NDM-1 using NMR spectroscopy has been previously demonstrated.

Purpose of the Study:

• To develop a cell-based NMR screening platform that integrates phenotypic and target-based screening.
• To identify potent inhibitors of NDM-1 activity within living bacterial cells.

Main Methods:

• Utilized Nuclear Magnetic Resonance (NMR) spectroscopy for real-time monitoring of enzymatic activity.
• Designed and implemented a cell-based screening assay using Escherichia coli engineered to express NDM-1.
• Quantified inhibitor potency using cellular IC50 values.

Main Results:

• Identified a potent inhibitor of NDM-1 with a cellular IC50 of 0.51 µM.
• The identified inhibitor is over 300-fold more potent than captopril, a known NDM-1 inhibitor.
• Demonstrated the feasibility of real-time, cell-based screening for enzyme inhibitors.

Conclusions:

• The developed cell-based NMR screening platform is effective for discovering potent enzyme inhibitors.
• This approach has broad applicability for screening targets in various cell types, including mammalian cells.
• The platform is suitable for targets that require a cellular environment for stability or function.