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Updated: Jul 9, 2026

Modeling Ligands into Maps Derived from Electron Cryomicroscopy
Published on: July 19, 2024
SALMON: solvent accessibility, ligand binding, and mapping of ligand orientation by NMR spectroscopy
Christian Ludwig1, Paul J A Michiels, Xiaoqiu Wu
1CR UK Institute for Cancer Studies, University of Birmingham, Vincent Drive, Edgbaston, Birmingham B15 2TT, UK.
Abstract:
Quinone oxidoreductase 2 (NQO2) binds the prodrug tretazicar (also known as CB1954, 5-(aziridin-1-yl)-2,4-dinitrobenzamide), which exhibits a profound antitumor effect in human cancers when administered together with caricotamide. X-ray structure determination allowed for two possible orientations of the ligand. Here we describe a new NMR method, SALMON (solvent accessibility, ligand binding, and mapping of ligand orientation by NMR spectroscopy), based on waterLOGSY to determine the orientation of a ligand bound to a protein by mapping its solvent accessibility, which was used to unambiguously determine the orientation of CB1954 in NQO2.
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