Cathepsins are a class of globular proteases, initially described as intracellular peptide
hydrolases, although several cathepsins also have extracellular functions. Cathepsins B, C,
F, H, L, K, O, S, V, W, and X are cysteine proteases of the papain family, and represent the
largest and best-known class of the cathepsins. Cathepsin G is a serine carboxypeptidases,
and cathepsins D and E are aspartic proteases. Cathepsins are synthesized as inactive
proenzymes and processed to become mature and active enzymes. Endogenous protein …