A Small-Molecule Microarray Approach for the Identification of E2 Enzyme Inhibitors in Ubiquitin-Like Conjugation Pathways

• Published in: SLAS discovery Vol. 22; no. 6; pp. 760 - 766
• Main Authors: Zlotkowski, Katherine, Hewitt, William M., Sinniah, Ranu S., Tropea, Joseph E., Needle, Danielle, Lountos, George T., Barchi, Joseph J., Waugh, David S., Schneekloth, John S.
• Format: Journal Article
• Language: English
• Published: Los Angeles, CA SAGE Publications 01.07.2017
• Subjects: Chromatography, Liquid; Drug Discovery - methods; Enzyme Inhibitors - pharmacology; Humans; Mass Spectrometry; Molecular Structure; Signal Transduction; Small Molecule Libraries; Structure-Activity Relationship; Sumoylation; Ubiquitin-Conjugating Enzymes - antagonists & inhibitors; Ubiquitin-Conjugating Enzymes - chemistry; Ubiquitin-Conjugating Enzymes - metabolism; small-molecule microarray; E2 enzymes; sumoylation; Ubc9
• ISSN: 2472-5552; 2472-5560
• DOI: 10.1177/2472555216683937

E2 enzymes in ubiquitin-like conjugation pathways are important, highly challenging pharmacological targets, and despite significant efforts, few noncovalent modulators have been discovered. Small-molecule microarray (SMM)–based screening was employed to identify an inhibitor of the “undruggable” small ubiquitin-like modifier (SUMO) E2 enzyme Ubc9. The inhibitor, a degradation product from a commercial screening collection, was chemically synthesized and evaluated in biochemical, mechanistic, and structure-activity relationship studies. Binding to Ubc9 was confirmed through the use of ligand-detected nuclear magnetic resonance, and inhibition of sumoylation in a reconstituted enzymatic cascade was found to occur with an IC50 of 75 µM. This work establishes the utility of the SMM approach for identifying inhibitors of E2 enzymes, targets with few known small-molecule modulators.