Biological Activity
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].
in vivo
Hippocampal CA1 neuronal programmed necrosis induced by global cerebral I/R injury is prevented by CA074-me (1 μg, 10 μg) both pre-treatment and post-treatment. The rupture of lysosomal membrane and the leakage of cathepsin-B, and this is strongly inhibited by CA074-me pre-treatment. The overexpression and nuclear translocation of RIP3 and the reduction of NAD+ level after I/R injury are also inhibited, while the upregulation of Hsp70 is strengthened by CA074-me pre-treatment[1].
CA-074Me (30 mg/kg) is capable of inhibiting osteoclastogenesis and bone degradation in vivo[2].
In the CVB+CA-074Me (4 mg/kg/day i.m.) guinea pigs group, the scores of inflammation significantly decrease in comparison with the CVB+None group. In CVB+CA-074Me group, the number of CD8+T cells decrease in comparison with the sham group[3].
References
[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.
