Z-Val-Val-Nle diazomethyl ketone is used as an irreversible cathepsin inhibitor that is 380 times more effective in inactivating cathepsin S than L. It is often abbreviated as DMK. Peptidyl diazomethyl ketones are specific inactivators of thiol proteinases.

This Thermo Scientific Chemicals brand product was originally part of the Alfa Aesar product portfolio. Some documentation and label information may refer to the legacy brand. The original Alfa Aesar product / item code or SKU reference has not changed as a part of the brand transition to Thermo Scientific Chemicals.