Used as a synthetic substrate in enzymatic assays to measure the activity of proteolytic enzymes, particularly chymotrypsin-like serine proteases such as neutrophil elastase. The compound is designed so that upon cleavage by the target enzyme, it releases p-nitroaniline—a yellow-colored product that can be easily detected and quantified spectrophotometrically at around 405 nm. This allows for real-time monitoring of enzyme kinetics, inhibition studies, and screening of potential protease inhibitors in biochemical and pharmaceutical research. Its specific peptide sequence (Ala-Ala-Pro-Val) enhances selectivity toward certain protease classes, making it valuable in mechanistic studies of enzyme specificity and function.