GSK 4027

GSK 4027 is a chemical probe for the PCAF/GCN5 bromodomain with an pIC₅₀ of 7.4±0.11 for PCAF in a time-resolved fluorescence resonance energy transfer (TR-FRET) assay. IC50 & Target: pIC50: 7.4±0.11 (PCAF)^[1] In Vitro: GSK 4027 is a PCAF/GCN5 bromodomain chemical probe. p300/CREB binding protein associated factor (PCAF/KAT2B) and general control nonderepressible 5 (GCN5/KAT2A) are multidomain proteins that have been implicated in retroviral infection, inflammation pathways, and cancer development. GSK 4027 also demonstrates potency toward BRD4 BD1 and BRD9 inTR-FRET assay with pIC₅₀s of <4.3 and 5.1±0.08, respectively. The selectivity of GSK 4027 against the wider bromodomain family is assessed in the BROMOscan panel with pK_i of 8.9 and 8.9 for PCAF and GCN5, respectively. GSK 4027 shows equipotent activity against PCAF and GCN5 with K_i of 1.4 nM for both bromodomains. As expected due to the encouraging measured artificial membrane permeability (500 nm/s), treatment of HEK293 cells with GSK 4027 displace full length PCAF from histone H3.3 with little drop-off from the biochemical assay and a pIC₅₀ 7.2 (IC₅₀ 60 nM)^[1].