Z-LLE-AMC is a fluorogenic substrate for the caspase-like post-glutamate peptide hydrolase of the 26S proteasome or 20S proteolytic core.1,2 Caspase-like activity can be quantified by fluorescent detection of free AMC (also known as 7-amino-4-methylcoumarin), which is excited at 340-360 nm and emits at 440-460 nm.