Cathepsin L: Proteins and Enzymes

Cathepsin L is a lysosomal cysteine protease expressed in most eukaryotic cells. Cathepsin L is known to hydrolyze a number of proteins, including the proform of urokinase-type plasminogen activator, which is activated by Cathepsin L cleavage. Cathepsin L has also been shown to proteolytically inactivate a1-antitrypsin and secretory leucoprotease inhibitor, two major protease inhibitors of the respiratory tract.