Protease Inhibitor Cocktail VIII

Protease Inhibitor Cocktail VIII is a cocktail of three protease inhibitors provided in DMSO. This cocktail is designed to inhibit a broad range of cysteine proteases, including calpains, cathepsins, and papain. This product specifically inhibits cysteine proteases using inhibitors such as 1.56 mM ALLN, 1.5 mM E-64 Protease Inhibitor, and 0.5 mM Cathepsin Inhibitor I.

Protease Inhibitor Cocktail VIII may be used:

• to maintain protein stability in downstream proteomic analyses such as Western blotting, immunoprecipitation, and mass spectrometry.
• to support accurate protein quantification and characterization in studies involving biomarker discovery and post-translational modifications.

Cysteine protease inhibitors generally work by targeting the enzyme′s active site, where a reactive cysteine residue acts as the catalytic nucleophile. The key step in inhibition is the formation of a covalent bond between the inhibitor and the sulfur atom (Sγ) of this critical cysteine residue, permanently blocking the enzyme′s proteolytic activity. Inhibitors like E-64 exploit this mechanism through its epoxy succinyl group, which undergoes an SN2-like reaction with the active Cys-25 Sγ atom.