ABSTRACT
Human cathepsin L is a ubiquitously expressed endopeptidase and is known to play critical roles in a wide variety of cellular signaling events. Its overexpression has been implicated in numerous human diseases, including highly invasive forms of cancer. Inhibition of cathepsin L is therefore considered a viable therapeutic strategy. Unfortunately, several redundant and even opposing roles of cathepsin L have recently emerged. Selective cathepsin L probes are therefore needed to dissect its function in context-specific manner before significant resources are directed into drug discovery efforts. Herein, the development of a clickable and tagless activity-based probe of cathepsin L is reported. The probe is highly efficient, active-site directed and activity-dependent, selective, cell penetrable, and non-toxic to human cells. Using zebrafish model, we demonstrate that the probe can inhibit cathepsin L function in vivo during the hatching process. It is anticipated that the probe will be a highly effective tool in dissecting cathepsin L biology at the proteome levels in both normal physiology and human diseases, thereby facilitating drug-discovery efforts targeting cathepsin L.
Subject(s)
Cathepsin L/antagonists & inhibitors , Molecular Probes/pharmacology , Animals , Catalytic Domain/drug effects , Cathepsin L/chemistry , Cell Line, Tumor , Cell Movement/drug effects , Click Chemistry , Humans , Molecular Probes/chemical synthesis , Molecular Probes/toxicity , ZebrafishABSTRACT
A hybrid-design approach is undertaken to develop a highly potent and selective inhibitor of human cathepsin L. Studies involving human breast carcinoma MDA-MB-231 cells establish that this inhibitor can successfully block intracellular cathepsin L activity, and retard the cell-migratory potential of these highly metastatic cells.
