Cathepsin E (CTSE, EC: 3.4.23.34) is a gastric aspartyl protease that functions as a disulfide-linked homodimer. This protease has a specificity similar to that of pepsin A and cathepsin D. It is an intracellular proteinase that is found in highest concentration on the surface of epithelial mucus-producing cells of the stomach. It is the first aspartic proteinase expressed in the fetal stomach and is found in more than half of the gastric cancers. Assay Genie's Cathepsin E Inhibitor Screening Kit utilizes the ability of Cathepsin E to cleave a synthetic MCA-based peptide substrate to release free MCA, which can be easily quantified using a fluorometer or fluorescence microplate reader. In the presence of a Cathepsin E-specific inhibitor, the cleavage of the substrate is reduced/abolished resulting in decrease or total loss of the MCA fluorescence. This simple and high-throughput adaptable assay kit can be used to screen/study/characterize the potential inhibitors of Cathepsin E.

Figure: Inhibition of Cathepsin E activity by CTSE Inhibitor. Assay was performed following the kit protocol.