Leupeptin is widely used in biochemical and cellular research as a protease inhibitor. It effectively inhibits serine, cysteine, and threonine proteases, making it valuable for studying protein degradation pathways and enzyme mechanisms. In cell culture experiments, leupeptin is often added to prevent protein breakdown, ensuring the integrity of proteins during extraction and analysis. It is also utilized in studies of apoptosis and autophagy, where it helps in understanding the role of proteases in these processes. Additionally, leupeptin is employed in the purification of proteins to minimize degradation and maintain their functional state. Its application extends to neuroscience research, where it aids in investigating the role of proteases in neurodegenerative diseases.