PF-CBP1 HCl is a highly selective inhibitor of the bromodomain of CREB-binding protein(CREBBP). It inhibits CREBBP (IC50: 125 nM) and p300 bromodomains (IC50: 363 nM).

p300 BD:363 nM, CREBBP:125 nM

PF-CBP1 modulates key inflammatory genes in primary macrophages, downregulates RGS4 in neurons (a target linked to Parkinson's disease), and exhibits 139-fold selectivity over BRD4 in biochemical assays and >105-fold selectivity by ITC. PF-CBP1 is a potent EP300 inhibitor with no cytotoxicity in macrophages and no hepatotoxicity in cell-based models at non-toxic concentrations.

Cells are pretreated with the probes PF-CBP1, ISOX-INACT, or ISOX-DUAL starting at 10 μM concentrations, and then serially diluted to 0.1 μM. After 30 min, the cells are treated with LPS to induce gene transcription and the expression levels of interleukin-6 (IL-6), IL-1β, and interferon-β (IFN-β)(which are known to be induced after 4 h of LPS exposure) are analyzed by RT-PCR. Probe PF-CBP1 moderately reduces LPS-induced IL-6 and IFN-β expression at 10 μM, and a decrease in IL-1β expression is evident at 3 μM.  (Only for Reference)