Donated Chemical Probes

GSK973

Target	BRD2 BRD3 BRD4 BRDT
Targeted domain	BD2
Mode of action	Inhibitor
Control	GSK943
Recommended cellular usage concentration	≤ 10 µM
In vivo use	Yes
Synonyms	Compound 36
Donated by	GlaxoSmithKline

Probe criteria

Inhibitor/agonist potency: goal is < 50 nM (IC₅₀, K_D)	Surpasses criterion: :BET mutant TR-FRET assay: BRD2 (BD1) pIC₅₀ = 4.4; (BD2) 7.5; 1260-fold BRD3 (BD1) pIC₅₀ = 4.5; (BD2) 7.8; 2000-fold BRD4 (BD1) pIC₅₀ = 4.6 ± 0.1 (n = 19); (BD2) 7.8 ± 0.2 (n = 16); 1600-fold BRDT (BD1) pIC₅₀ = 4.5; (BD2) 7.4; 800-fold BROMOScan (DiscoverX): BRD2 (BD1): pK_d =5.3; (BD2) 8.3; 1000-fold BRD3 (BD1): pK_d= 5.2; (BD2) 8.5 ; 2000-fold BRD4 (BD1): pK_d =5.6; (BD2)8.7; 1260-fold BRDT (BD1): pK_d = 5.4; (BD2) 8.3; 800-fold SPR BRD4 (BD1): K_d > 3 µM; BRD4 (BD2) K_d = 34 nM
Selectivity within target family: > 30-fold	Surpasses criterion:: BROMOScan (DiscoverX) (34 tested): selective for the BD2 domain of BET proteins; closest hits: TAF1 BD2 (pKd = 6.4), TAF1L BD2 (pKd = 5.7), BRD9 (pKd = 5.7), CECR2 (pKd = 5.5), BAZ2A (pKd = 5.5) and BAZ2B (pKd = 5.1)
Selectivity outside target family	Selectivity screen (48 targets tested): clean Chemoproteomics data (3 vectors) showed excellent non BCPs selectivity Off-targets in the PDSP scan are DRD3 Ki = 257.47 nM, DRD4 Ki = 982.65 nM and DRD2 Ki = 964.05 nM
On target cell activity for cell-based targets: goal is < 1 µM IC₅₀/EC₅₀	Surpasses criterion: Lipopolysaccharide (LPS)-stimulated human whole blood assay: MCP-1 (pIC₅₀ =7.3)
Control compound (100 times less potent than the probe)	Surpasses criterion: Enantiomer GSK943 BET mutant TR-FRET assay: BRD4 (BD1) pIC₅₀ < 4.3; (BD2) = 5.1, 500-fold Clean PDSP scan except for one off-target: GABAA/BZP (Ki = 473.91 nM)