CA-074 is a synthetic analogue of E-64, a natural peptidyl epoxide that irreversibly inhibits most known lysosomal cysteine proteinases, and is developed by means of rational drug design, exploiting the dipeptidylcarboxypeptidase activity of cathepsin B. CA-074 can be used to selectively inhibit cathepsin B within living cells, as long as the experimental conditions permit significant fluid-phase endocytosis of the drug. CA-074 inhibits cathepsin B with a Ki of 2 to 5 nM, whereas the initial Kis for cathepsin H and L are about 40-200 μM. CA-074 exhibits 10000-30000 times greater inhibitory effects on purified rat cathepsin B than on cathepsin H and L.
Medlife has not independently confirmed the accuracy of these methods. They are for reference only.