Cathepsin L (CTSL, EC 3.4.22.15) is a lysosomal cysteine protease that is implicated in protein degradation, arthritis, apoptosis, and cancer. Assay Genie's Cathepsin L Inhibitor Screening Kit utilizes the ability of active Cathepsin L to cleave the synthetic AFC-based peptide substrate to release AFC, which can be easily quantified using a fluorometer or fluorescence microplate reader. In the presence of a Cathepsin L inhibitor, the cleavage of this substrate is reduced/abolished resulting in decrease or total loss of the AFC fluorescence. This simple and high-throughput adaptable assay kit can be used to screen/study/characterize potential inhibitors of Cathepsin L.

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