Proteolysis Targeting Chimera
PROTAC (PROtein TArgeting Chimeric) is the ability to specifically degrade a protein using the endogenous machinery of the cell. This approach is applicable to elimination of established drug target proteins and the “undruggable” proteome. We generate a chimeric small molecule with two “warheads”, one that binds to the protein of interest, the second that binds to the E3 ligase and joined by a linker that brings both into close proximity. The ligase ubiquitinates the protein for degradation inside the cell.
How do we develop assays for PROTAC?
- WEStern Blotting:
We use WES (ProteinSimple) to monitor target protein levels in cells following treatment with PROTAC test compounds. It is highly quantitative compared to traditional Western blotting.
Screen of 10 PROTAC compounds. Negative control (untreated cells) and positive control were run in duplicate. Positive control is a known active PROTAC molecule. Loading control is Vinculin.
Proteins can be labelled either with Nanoluc or HiBiT (Promega) and luminescence can be used to monitor protein levels in living cells.
Protein of interest is expressed with either Nanoluc or HiBiT as the label in cells (either transient or CRISPR).