Used in enzymatic assays to study protease activity, particularly for serine proteases like trypsin and chymotrypsin. The compound acts as a chromogenic substrate—the cleavage of the ester bond by the enzyme releases p-nitrophenol, which produces a yellow color detectable at 405 nm. This allows real-time monitoring of enzyme kinetics and inhibition. Commonly applied in screening inhibitors, characterizing enzyme specificity, and assessing catalytic efficiency in biochemical research. Its Z-protected amino group enhances substrate stability and influences enzyme selectivity.