Used in biochemical research as a selective proteasome inhibitor, particularly targeting the chymotrypsin-like activity of the 20S proteasome. It is employed in studies related to protein degradation pathways, cancer cell apoptosis, and ubiquitin-proteasome system regulation. Due to its complex peptide-like structure and specific stereochemistry, it serves as a tool compound for investigating protease function and for developing targeted protein degradation therapies. Commonly applied in in vitro assays using cell lines to modulate proteasomal activity and assess downstream effects on cell cycle progression and survival.