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Updated: Feb 4, 2026

Identifying the Binding Proteins of Small Ligands with the Differential Radial Capillary Action of Ligand Assay DRaCALA
Published on: March 19, 2021
Specific protein-labeling and ligand-binding position analysis with amidopyrene probes as LDI MS tags
Rei Watanabe1, Yaping Hu, Keita Iio
1Graduate School of Pure and Applied Sciences, University of Tsukuba, 1-1-1 Tennodai, Tsukuba, 305-8571, Japan. kigoshi@chem.tsukuba.ac.jp.
Abstract:
To readily analyze the binding mode of protein-ligand interactions, we developed ligand-bound-type and ligand-dissociation-type probes having 6-amidopyrene (apy) as a detecting group. Matrix- and label-assisted laser desorption/ionization mass spectrometry (MALDI and LA-LDI MS) analyses and a covalent docking simulation using these probes precisely determined the binding position of the ligand biotin on the target protein avidin (RMSD = 0.786 and 0.332 Å). Our apy-probe-labeling method may be useful for determining the unknown ligand-binding sites of various target proteins.
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