Work

Functionalized Scout Fragments for Site-Specific Covalent Ligand Discovery and Optimization

Year: 2021

Type: article

Abstract: Covalent ligands are a versatile class of chemical probes and drugs that can target noncanonical sites on proteins and display differentiated pharmacodynamic properties. Chemical proteomic methods have been introduced that leverage electrophilic fragments to globally profile the covalent ligandability of nucleophilic residues, such as cysteine and lysine, in native biological systems. Further optimization of these initial ligandability events without resorting to the time-consuming process of individualized protein purification and functional assay development, however, presents a persistent technical challenge. Here, we show that broadly reactive electrophilic fragments, or "scouts", can be converted into site-specific target engagement probes for screening small molecules against a wide array of proteins in convenient gel- and ELISA-based assay formats. We use these assays to expediently optimize a weak potency fragment hit into a sub-μM inhibitor that selectively engages an active-site cysteine in the retinaldehyde reductase AKR1B10. Our findings provide a road map to optimize covalent fragments into more advanced chemical probes without requiring protein purification or structural analysis.

Source: ACS Central Science

DOI: 10.1021/acscentsci.0c01336

Authors: Vincent M. Crowley, Marvin Thielert, Benjamin F. Cravatt

Institution: Scripps Research Institute

Language: English

Topic: Click Chemistry and Applications

Subfield: Organic Chemistry

Field: Chemistry

Domain: Physical Sciences

Open Access status: diamond

Funders: National Cancer Institute, National Institute of Allergy and Infectious Diseases, National Institute of Neurological Disorders and Stroke