Live cell imaging and profiling of cysteine cathepsin activity using a quenched activity-based probe

Abstract

Since protease activity is highly regulated by structural and environmental influences, the abundance of a protease often does not directly correlate with its activity. Because in most of the cases it is the activity of a protease that gives rise to its biological relevance, tools to report on this activity are of great value to the research community. Activity-based probes (ABPs) are small molecule tools that allow for the monitoring and profiling of protease activities in complex biological systems. The class of fluorescent quenched ABPs (qABPs), being intrinsically “dark” and only emitting fluorescence after reaction with the target protease, are ideally suited for imaging techniques such..