Accelerated Screening of Protein-Ligand Interactions via Parallel T₂-Weighted ¹⁹F-MRI

Area of Science:

• Biophysics
• Chemical Biology
• Drug Discovery

Background:

• Ligand screening is crucial for drug discovery, but current methods like Nuclear Magnetic Resonance (NMR) have limited throughput.
• Magnetic Resonance Imaging (MRI) offers inherent parallelism and can encode parameters in images, suggesting potential for higher throughput screening.

Purpose of the Study:

• To explore the application of 19F-MRI for parallel characterization of protein-ligand interactions.
• To demonstrate the detection of ligand binding and determination of ligand affinity using 19F-MRI.

Main Methods:

• Utilized a custom-built 9-fold sample holder and a 19F-MRI coil for parallel measurements.
• Employed T2-weighted 19F-MRI to detect binding of 4-(trifluoromethyl)benzamidine (TFBA) to trypsin.
• Determined the affinity of non-fluorinated ligands via competition assays by monitoring TFBA displacement.

Main Results:

• Successfully detected ligand binding using T2-weighted 19F-MRI.
• Demonstrated parallel determination of non-fluorinated ligand affinity through dose-dependent displacement of TFBA.
• Derived the affinity of benzamidine (BA) by comparing parallel 19F-T2-weighted MR images.

Conclusions:

• 19F-MRI enables parallel characterization of protein-ligand interactions, significantly increasing throughput for biochemical assays.
• This approach holds promise for drug discovery, with potential for enhanced sensitivity when combined with hyperpolarization techniques.