proteasome inhibitor-1

PSI is a proteasome inhibitor.

PSI (TFA) is a potent proteasome inhibitor effective against the proliferation of primary effusion lymphoma (PEL) cells, utilized in the study of Kaposi's sarcoma-associated herpesvirus (KSHV) infection and related lymphomas [1].

PR-39 TFA, a natural peptide rich in proline and arginine with antibacterial properties, acts as a noncompetitive, reversible, and allosteric inhibitor of the proteasome. It specifically attaches to the α7 subunit of the proteasome, preventing the degradation of the NF-κB inhibitor IκBα through the ubiquitin-proteasome pathway. Additionally, PR-39 TFA promotes angiogenesis, suppresses inflammatory responses, and notably decreases myocardial infarct size in mice [1] [2].

Z-GGF-CMK, a protease inhibitor, impedes ClpP1P2 and proteasome activity and demonstrates cytotoxic effects on HepG2 cells, with a CC50 value of 125 μM [1].

Baceridin, a cyclic hexapeptide and proteasome inhibitor, can be isolated from the culture medium of Epiphytic Bacillus. It has the ability to impede cell cycle progression and induce apoptosis in tumor cells via a p53-independent pathway, making it a valuable agent in cancer research [1].

Z-Gly-Pro-Phe-Leu-CHO (Z-GPFL-CHO) is a tetrapeptide aldehyde that acts as a selective and potent proteasome inhibitor, with inhibition constants (Ki) of 1.5 µM for branched-chain amino acid-preferred, 2.3 µM for small neutral amino acid-preferred, and 40.5 µM for chymotrypsin-like activities, and an inhibitory concentration (IC50) of 3.1 µM for peptidyl-glutamyl peptide hydrolyzing activity [1].