Developing Protein Observed 19F NMR for Fragment-Based Screening to Target ProteinProtein Interactions
Clifford T. Gee*, William C. Pomerantz
Department of Chemistry, University of Minnesota,
207 Pleasant St SE, Minneapolis, MN, 55455
This poster describes my recent work in performing the first demonstration of a full
fragment screen using Protein Observed 19F (PrOF) NMR targeting the KIX binding domain of
the transcriptional coactivator CREB Binding Protein (CBP). Protein-protein interactions (PPIs)
play a vital role in biological processes, making the ability to selectively target and modulate
PPIs an important therapeutic challenge due to the links between dysregulated PPIs and disease.1
While PPIs have long been thought to be undruggable, recent successes by Wells, Fesik,
Vassilev, and others have shown the situation to be challenging but not impossible.2 The central
hypothesis of this project is that PrOF NMR can be used as a powerful fragment-based screening
method to accomplish this goal. Fluorine is a useful NMR active nucleus due to its sensitivity to
subtle changes in its chemical environment and its ability to rapidly acquire structural
information regarding ligand binding or protein folding while overcoming challenges faced by
other screening methods, such as superfluous background signals and probe insensitivity,3
making PrOF NMR an ideal fragment-based screening method.4,5
Using PrOF NMR, the binding activity of small-molecules to the fluorinated protein is
assessed by perturbations of the peaks in the protein’s 19F NMR spectrum. Thus far, I have
screened 508 compounds, which has yielded 15 statistically relevant mixture hits. From
deconvoluting those mixtures, I have identified several small-molecule ligands, evaluated the
structure-activity relationship (SAR), and determined the binding affinities for KIX of four of the
compounds. Ligand observed NMR has also been used as a secondary validation method.
Further characterization of these compounds is ongoing.
Literature Citations
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(2)
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(4)
(5)
Yan, C.; Higgins, P. J., Drugging the undruggable: Transcription therapy for cancer.
Biochim. Biophys. Acta. 2013, 1835, 76-85.
Arkin, M. R.; Wells, J. A., Small-molecule inhibitors of protein-protein interactions:
progressing towards the dream. Nat. Rev. Drug. Discov. 2004, 3, 301-17.
Kitevski-LeBlanc, J. L.; Prosser, R. S., Current applications of 19F NMR to studies of
protein structure and dynamics. Prog. Nucl. Magn. Reson. Spectrosc. 2012, 62, 1-33.
Hajduk, P. J.; Greer, J., A decade of fragment-based drug design: strategic advances and
lessons learned. Nat. Rev. Drug. Discov. 2007, 6, 211-9.
Pomerantz, W. C.; Wang, N.; Lipinski, A. K.; Wang, R.; Cierpicki, T.; Mapp, A. K.,
Profiling the dynamic interfaces of fluorinated transcription complexes for ligand
discovery and characterization. ACS Chem. Biol. 2012, 7, 1345-50.