This chemical is primarily used as a substrate in enzymatic assays to study the activity of proteases, particularly elastase. When elastase cleaves the peptide bond in this compound, it releases p-nitroaniline, which can be easily detected spectrophotometrically due to its yellow color. This allows researchers to quantify enzyme activity and study enzyme kinetics. It is also employed in biochemical research to investigate the specificity and efficiency of various proteolytic enzymes. Additionally, it serves as a tool in drug discovery to screen and evaluate potential inhibitors of elastase, which is relevant in conditions like emphysema and cystic fibrosis.