Description
Cathepsins are a group of intracellular proteolytic enzymes located within the lysosomes. On the basis of the specificity towards their substrates, the cathepsins have been assigned the names: Cathepsins A, B, C, D, E, G H and L. Cathepsin G is a serine protease, it consists of a single polypeptide with a MW of 30kD as determined by SDS-PAGE. Its substrates are collagen and proteoglycans. Cathepsins are localized primarily in lysosomes or endosomes, but translocated to the cytosol during apoptosis. The translocation allows these proteases to interact with caspases or other apoptosis signaling mechanisms. Studies show that cathepsins cleave certain caspases, and caspase inhibitors can inhibit cathepsin activity in vitro