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Updated: May 23, 2026

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Identification of Small Molecule-binding Proteins in a Native Cellular Environment by Live-cell Photoaffinity Labeling
Published on: September 20, 2016
Global protein-ligand binding affinity profiling via photocatalytic labeling
Charles D Warren1, Noah Yardeny1, Siyang Peng2
1Tri-Institutional PhD Program in Chemical Biology (TPCB), New York, NY, USA.
Nature Communications
|May 21, 2026
Summary
A new method, Affinity Map, enables simultaneous identification and measurement of protein-ligand binding affinities. This platform offers a general approach for profiling interactions across various ligand types in complex biological samples.
Area of Science:
- Biochemistry
- Proteomics
- Chemical Biology
Background:
- Protein-ligand interactions are crucial for drug action and cellular signaling.
- Current methods for identifying and quantifying these interactions are often indirect, low-throughput, or limited to specific protein classes.
- Simultaneous target identification and affinity measurement remain a significant challenge in chemical biology.
Purpose of the Study:
- To develop a generalizable platform for global quantitative binding affinity profiling.
- To enable simultaneous target identification and biophysical affinity measurement for diverse ligand types.
- To overcome limitations of existing methods in measuring interactions within native biological environments.
Main Methods:
- Competitive binding analysis coupled with high-fidelity photocatalytic labeling.
- High-throughput proteomics for global quantitative binding affinity profiling.
- Application of the Affinity Map platform to cell lysates, organ extracts, and live cell surfaces.
Main Results:
- Demonstrated the applicability of Affinity Map to major ligand classes: small molecules, linear peptides, cyclic peptides, and proteins.
- Successfully measured binding affinities between unmodified ligands and proteins in complex biological matrices.
- Established a robust method for comprehensive analysis of protein-ligand interactions.
Conclusions:
- Affinity Map provides a versatile and generalizable platform for quantitative binding affinity profiling.
- The method facilitates the study of protein-ligand interactions across diverse biological contexts and ligand types.
- This approach advances the understanding of molecular interactions in drug discovery and cell biology.

