SP-Chymostatin B is a potent inhibitor of many proteases, including chymotrypsin, papain, chymotrypsin-like serine proteinases, chymases, and lysosomal cysteine proteinases. It weakly inhibits human leucocyte elastase. It is effective at a final concentra
Aclacinomycin A (Aclarubicin) hydrochloride is a fluorescent molecule and the first described non-peptidic inhibitor showing discrete specificity for the CTRL (chymotrypsin-like) activity of the 20S proteasome. Aclacinomycin A hydrochloride is also a dual inhibitor of topoisomerase I and II.
Tripeptidyl peptidase II (TPPII) is a serine peptidase of the subtilisin-type which removes tripeptides from the free NH2 terminus of oligopeptides. AAF-CMK is an irreversible inhibitor of TPPII commonly used at 10-100 μM. It does not significantly interfere with the chymotrypsin-like activity of the proteasome. AAF-CMK also inhibits bleomycin hydrolase and puromycin-sensitive aminopeptidase when used at 50 μM.
Broussonins A and B, new phytoalexins from diseased paper mulberry. Broussonin B can induce neurite outgrowth in PC-12 cells at concentration of 50 microg/ml, and show moderate inhibitory activities against a chymotrypsin-like activity of the proteasome.B
Z-LLL-AMC is a fluorogenic substrate for the chymotrypsin-like activity of the 26S proteasome or 20S proteolytic core. Chymotrypsin-like activity can be quantified by fluorescent detection of free AMC (also known as 7-amino-4-methylcoumarin), which is excited at 340-360 nm and emits at 440-460 nm. Z-LLL-AMC is typically used in cell lysates after experimental treatment.
CEP-18770 is an orally bioavailable synthetic P2 threonine boronic acid inhibitor of the chymotrypsin-like activity of the proteasome, with potential antineoplastic activity. Proteasome inhibitor CEP 18770 represses the proteasomal degradation of a variety of proteins, including inhibitory kappaBalpha (IkappaBalpha), resulting in the cytoplasmic sequestration of the transcription factor NF-kappaB; inhibition of NF-kappaB nuclear translocation and transcriptional up-regulation of a variety of cell growth-promoting factors; and apoptotic cell death in susceptible tumor cell populations. In vitro studies indicate that this agent exhibits a favorable cytotoxicity profile toward normal human epithelial cells, bone marrow progenitors, and bone marrow-derived stromal cells relative to the proteasome inhibitor bortezomib. The intracellular protein IkappaBalpha functions as a primary inhibitor of the proinflammatory transcription factor NF-kappaB.