Cathepsins - A class of globular lysosomal proteases
Cathepsins play a vital role in mammalian cellular turnover. There are currently 12 family members, which degrade polypeptides and are distinguished by their substrate specificities.
Elevated levels of Cathepsin B were detected in metastases and neurological disorders including Alzheimer's disease (AD).
Cathepsin D is a lysosomal aspartic proteinase, active in intracellular protein breakdown. It is involved in the pathogenesis of several diseases such as breast cancer and Alzheimer’s disease.
Cathepsin E is a non-lysosomal aspartic proteinase of the pepsin superfamily. It plays an important role in protein degradation, the generation of bioactive proteins, and antigen processing. Recent studies have particularly suggested that Cathepsin E is important in host defense against cancer cells and invading microorganisms.
Cathepsin G is the serine protease released by neutrophils upon their activation. Cathepsin G is currently being explored as a target for anti-inflammatory and anti-infective drugs.
Cathepsin K is the lysosomal cysteine protease involved in bone remodeling and resorption. It is a potential drug target in autoimmune diseases and osteoporosis.
Cathepsin L, a lysosomal endopeptidase, is a member of the papain-like family of cysteine proteinases. It is involved in the promotion of tumor cell invasion, antigen processing and turnover of intracellular and secreted proteins.
Cathepsin S is a cysteine proteinase involved in the pathogenesis of autoimmune diseases, atherosclerosis, cancer, obesity and related diseases.