Leupeptin is a competitive protease inhibitor produced by actinomycetes. Leupeptin can inhibit cysteine, serine and threonine peptidases. Leupeptin inhibits serine proteinases (trypsin (Ki=3.5 nM), plasmin (Ki= 3.4 nM), porcine kallikrein), and cysteine p
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.
K-252c is a staurosporine analog isolated from Nocardiopsis sp. and is a cell-permeable PKC inhibitor (IC50: 2.45 μM). K-252c also inhibits β-lactamase, chymotrypsin, and malate dehydrogenase. K-252c causes apoptosis in human chronic myelogenous leukemia cancer cells.