Background:

CA-074 Me is a membrane-permeable and selective inhibitor of cathepsin B with IC50 value of 36.3 nM [1, 2].

CA-074 Me is a methyl ester derivative of CA-074. In cultured human gingival fibroblasts, CA-074 Me exerted a 95% inhibition of cathepsin B and partial inhibition (54%) of the combined activities of cathepsins B and L. CA-074 Me was also found to inhibit cathespin L under reducing conditions. It inhibited the activity of purified human cathepsin L by more than 90% when the enzyme had been pre-incubated with 1.4 mM DTT or 4.2 mM GSH for 2 hours. Besides that, CA-074 Me completely inhibited cathepsin B in the presence of 1.4 mM DTT [2, 3].

参考文献:
[1] Wu X, Zhang L, Gurley E, et al. Prevention of free fatty acid–induced hepatic lipotoxicity by 18β-glycyrrhetinic acid through lysosomal and mitochondrial pathways. Hepatology, 2008, 47(6): 1905-1915.
[2] Steverding D. The cathepsin B-selective inhibitors CA-074 and CA-074Me inactivate cathepsin L under reducing conditions. Open Enzyme Inhibition Journal, 2011, 4: 11-16.
[3] Buttle D J, Murata M, Knight C G, et al. CA074 methyl ester: a proinhibitor for intracellular cathepsin B. Archives of biochemistry and biophysics, 1992, 299(2): 377-380.