title: A Small-Molecule Microarray Approach for the Identification of E2 Enzyme Inhibitors in Ubiquitin-Like Conjugation Pathways.
abstract: 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 IC50of 75 µM. This work establishes the utility of the SMM approach for identifying inhibitors of E2 enzymes, targets with few known small-molecule modulators.
authors.affiliation: 1 Chemical Biology Laboratory, Center for Cancer Research, National Cancer Institute, Frederick, MD, USA.
authors.forename: Katherine
authors.initials: K
authors.lastname: Zlotkowski
authors.affiliation: 1 Chemical Biology Laboratory, Center for Cancer Research, National Cancer Institute, Frederick, MD, USA.
authors.forename: William M
authors.initials: WM
authors.lastname: Hewitt
authors.affiliation: 1 Chemical Biology Laboratory, Center for Cancer Research, National Cancer Institute, Frederick, MD, USA.
authors.forename: Ranu S
authors.initials: RS
authors.lastname: Sinniah
authors.affiliation: 2 Macromolecular Crystallography Laboratory, Center for Cancer Research, National Cancer Institute, Frederick, MD, USA.
authors.forename: Joseph E
authors.initials: JE
authors.lastname: Tropea
authors.affiliation: 2 Macromolecular Crystallography Laboratory, Center for Cancer Research, National Cancer Institute, Frederick, MD, USA.
authors.forename: Danielle
authors.initials: D
authors.lastname: Needle
authors.affiliation: 2 Macromolecular Crystallography Laboratory, Center for Cancer Research, National Cancer Institute, Frederick, MD, USA.|3 Basic Science Program, Leidos Biomedical Research Inc., Frederick National Laboratory for Cancer Research, Frederick, MD, USA.
authors.forename: George T
authors.initials: GT
authors.lastname: Lountos
authors.affiliation: 1 Chemical Biology Laboratory, Center for Cancer Research, National Cancer Institute, Frederick, MD, USA.
authors.forename: Joseph J
authors.initials: JJ
authors.lastname: Barchi
authors.affiliation: 2 Macromolecular Crystallography Laboratory, Center for Cancer Research, National Cancer Institute, Frederick, MD, USA.
authors.forename: David S
authors.initials: DS
authors.lastname: Waugh
authors.affiliation: 1 Chemical Biology Laboratory, Center for Cancer Research, National Cancer Institute, Frederick, MD, USA.
authors.forename: John S
authors.initials: JS
authors.lastname: Schneekloth
mesh_terms: D002853:Chromatography, Liquid; D055808:Drug Discovery / Q000379:methods; D004791:Enzyme Inhibitors / Q000494:pharmacology*; D006801:Humans; D013058:Mass Spectrometry; D015394:Molecular Structure; D015398:Signal Transduction; D054852:Small Molecule Libraries; D013329:Structure-Activity Relationship; D058207:Sumoylation; D044763:Ubiquitin-Conjugating Enzymes / Q000037:antagonists & inhibitors* / Q000737:chemistry / Q000378:metabolism; D000098843:Ubiquitin-Conjugating Enzyme UBC9
chemical_list: D004791:Enzyme Inhibitors; D054852:Small Molecule Libraries; D044763:Ubiquitin-Conjugating Enzymes; D000098843:Ubiquitin-Conjugating Enzyme UBC9
keywords: E2 enzymes; Ubc9; small-molecule microarray; sumoylation