PF-CBP1

Antagonist of EP300, CREBBP

Structure

Information

  • EP300
  • CREBBP
  • Antagonist
  • 100 nM - 1 uM

In Vitro Validations

Uniprot ID: Q09472
Target Class: Epigenetic
Target SubClass: Bromodomain
Potency: IC 50
Potency Value: 363 nM
Potency Assay: FRET
PDB ID for probe-target interaction (3D structure): --
Target aliases:
Histone acetyltransferase p300, P300, EP300, EP300 ...

DOI Reference: 10.1016/j.chembiol.2015.10.013

In Cell Validations

In Vivo Data

No in Vivo Validations

Off-Target Selectivity Assesments

Potency end-point : IC50
Potency assay (off target): In BROMOscan assay, testing 19 bromodomains, only CBP/EP300 was affected at < 1 uM; BRD4 KD > 20 uM (by ITC)
Probe Selectivity in Vitro:
PF-CBP1 displays greater than 100-fold selectivity for the bromodomain of CBP over those of BRD4 and a panel of other proteins, it against BRD2-1,BRD3-1, BRD3-2,BRD4-1, BRD4-2, BRDT-1, TAF1-2, and TAF1L-2 with IC50 values of 1.24 μM, 1.38 μM, 4.22 μM, 1.54 μM, 9.75 μM, 2.44 μM, 3.39 μM and 7.29 μM, respectively. BRD4 (Kd>20 μM)
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SERP ratings and comments


SERP Ratings

In Cell Rating

SERP Comments:

The biochemical, cellular and ITC data reported in the reference (Chem Biol 2015, 22, 1588-1596) support the use of PF-CBP1 as a selective probe for the interrogation of the function of CBP bromodomain in cells. In a slightly later publication (10.1021/acs.jmedchem.6b01022), however, the selectivity versus BRD4 using a different biochemical assay format is reported as being in the 10-fold range rather than 100-fold. 

(last updated: 28 Mar 2017 )

SERP Ratings

In Cell Rating

SERP Comments:

I believe this is the best CRBP probe available, but it is far from ideal. It is only weakly potent. Ideally it would be <100 nM but it is only active in cells at or above 1 uM. The margin to BRD4 potency (18 uM) is ~100-fold based on FP but is worse in the Bromoscan panel, so care must be taken not to use it at a concentration that causes BRD4 inhibition. Given that BRD4 inhibitors show a drop off in potency of ~10-fold in cells, I would suggest at concentration of 1-10 uM so this compound will not inhibit BRD4. The compound is also potent against EP300 due to close homology with CRBP and other BRDs are inhibited with <100-fold selectivity.

(last updated: 6 Apr 2017 )

SERP Ratings

In Cell Rating

SERP Comments:

PF-CBP1 mildly downregulated expression of key inflammatory genes (e.g., IL6, IL1B, IFNB, TNF) in J774, a murine macrophage cell line, at concentrations typically >/=1 uM and did not show cytotoxicity. Additionally, the compound downregulated RGS4 (a CBP-downstream target gene linked to Parkinson’s disease) in neurons. No in vivo model organism data is available as of yet.

(last updated: 26 Jul 2017 )