immunoproteasome β1c

UK-101 is a small molecule inhibitor and a selective inhibitor of the immunoproteasome β1i (LMP2) subunit (IC50=104 nM), with 144-fold and 10-fold selectivity over the β1c and β5 subunits, respectively. This compound can induce apoptosis, possesses antitumor activity, and can be used for prostate cancer-related research.

Argyrin B is a naturally occurring cyclic peptide that acts as a reversible non-competitive inhibitor of the immunoproteasome. It exhibits higher inhibitory selectivity for the β5i and β1i sites of the immunoproteasome compared to the β5c and β1c sites of the constitutive proteasome, being nearly 20 times more selective for β1i than for its homolog β1c. Additionally, Argyrin B possesses antibacterial properties.