Chymostatin is a reversible protease inhibitor, inhibiting chymotrypsin, chymotrypsin-like serine proteases, chymases and lysosomal cysteine proteinases such as cathepsins B, H and L. It weakly inhibits human leucocyte elastase. It is effective at a final concentration of 100-200 ug/mL (10 to 100 uM), although the working solution is not stable (the terminal aldehyde is subject to oxidation). Useful in protease inhibitor cocktails for plant extracts.
Chymostatin is used in production of extracellular proteolytic activity by Histoplasma capsulatum grown in Histoplasma-macrophage medium is limited to RFLP class 1 isolates. Chymostatin has been used in a study that determined that molecular calculations are useful for evaluating the interactions between ligands, including inhibitors and homologous enzymes, in docking models. Chymostatin has also been used in a study to investigate the norovirus protease as an attractive target for antiviral drug development.