Cathepsins and Granzymes

Proteases are important biological enzymes involved in tissue remodeling, organ development, immunity and cancer development and metastases. The Cathepsins are made up of ~12 members classified via catalytic mechanism, structure, and by the target proteins cleaved. Cathepsins are generally located in the lysosome, where enzymatic activity is generally regulated by the low pH conditions found in the organelle. Cathepsin K is not generally found in the lysosome but is instead secreted. This is done primarily by osteoclasts and aids in the bone resorption process.
Granzymes are a class of specialized proteases secreted in granules released by cytotoxic T cells and Natural Killer cells. They are secreted when the T or NK cells recognize cells that have been virally infected. Upon recognition, granzymes are secreted and with the aid of perforin, gain access into the target, virally infected cells. Once in the target cells, granzymes cleave pro-caspase 3 into the pro-apoptotic caspase 3. Thus, apoptosis is induced and the virally infected cell is removed.

Granzyms and cathepsins are vital areas of research for drug discovery and basic research. Sigma-Aldrich offers an assortment of products and resources for their study, including:

  • Inhibitors that block granzyme and cathepsin activity
  • An assortment of antibodies to the various proteases
  • Kits to assay function
  • Purified enzymes

Search below for the granzyme and cathepsin product to fit your research needs.