PFI-7 Chemical probe for GID4, substrate-recognition subunit of the CTLH E3 ubiquitin-protein ligase complex

The probe is available at Sigma.

The control can be requested by clicking here.


Pfizer in collaboration with the SGC have developed PFI-7, a potent, cell active chemical probe for the E3 ligase GID4. PFI-7 binds potently to GID4 with KD = 0.08 μM (SPR) and displaces the known degron1 peptide in a NanoBRETTM assay with EC50 = 0.6 μM. PFI-7N is a closely related negative control with KD = 5 μM (SPR). A co-crystal structure has been deposited.

Chemical probe/control pair

We have further developed a handle PFI-E3H1 and a PEGylated analogue to show that the handle tolerates a substitution. These findings offers opportunities to synthesize proximity-inducing or degrader modalities2

selectivity profile
in vitro potency

[PFI-7] (μM)

[PFI-7] (μM)

cell based assay data

A NanoBRET assay was used to show target engagement in cells. 

The interaction was between NanoLuc® tagged degrons and full-length GID4.

  1. Cheng Dong, Heng Zhang, Li Li, Wolfram Tempel, Peter Loppnau & Jinrong Min. Molecular basis of GID4-mediated recognition of degrons for the Pro/N-end rule pathway. Nature Chemical Biology 14, 466-473 (2018).​
  2. Aleša Bricelj, Christian Steinebach, Robert Kuchta, Michael Gütschow, and Izidor Sosič. E3 Ligase Ligands in Successful PROTACs: An Overview of Syntheses and Linker Attachment Points, ; Milka Kostic. Targeted Protein Degradation and Proximity-Based Pharmacology, .
pk properties
co-crystal structures

Main features

  • PFI-7 bound to GID4 substrate-binding pocket
  • Structure overview
  • Overlap with substrate peptide
synthetic schemes
materials and methods