%0 Journal Article
%T Rapid Protein-Ligand Affinity Determination by Photoinduced Hyperpolarized NMR.
%A Bütikofer M
%A Stadler GR
%A Kadavath H
%A Cadalbert R
%A Torres F
%A Riek R
%J J Am Chem Soc
%V 146
%N 26
%D 2024 Jul 3
%M 38957136
%F 16.383
%R 10.1021/jacs.4c04000
%X The binding affinity determination of protein-ligand complexes is a cornerstone of drug design. State-of-the-art techniques are limited by lengthy and expensive processes. Building upon our recently introduced novel screening method utilizing photochemically induced dynamic nuclear polarization (photo-CIDNP) NMR, we provide the methodological framework to determine binding affinities within 5-15 min using 0.1 mg of protein. The accuracy of our method is demonstrated for the affinity constants of peptides binding to a PDZ domain and fragment ligands binding to the protein PIN1. The method can also be extended to measure the affinity of nonphoto-CIDNP-polarizable ligands in competition binding experiments. Finally, we demonstrate a strong correlation between the ligand-reduced signals in photo-CIDNP-based NMR fragment screening and the well-established saturation transfer difference (STD) NMR. Thus, our methodology measures protein-ligand affinities in the micro- to millimolar range in only a few minutes and informs on the binding epitope in a single-scan experiment, opening new avenues for early stage drug discovery approaches.