Description
General description
Research Area: Cell Signaling
Dipeptidyl peptidase I (DPPI), also known as cathepsin C, is an abundant lysosomal cysteine protease from the papain superfamily with a molecular weight of approximately 200 kDa. It is widely expressed in a variety of mammalian tissues, with the highest levels found in the lungs, kidneys, liver, and spleen, and relatively lower levels in the brain.
DPPI is the only member of its family that is functional as a tetramer, consisting of four identical subunits, each composed of an N-terminal fragment, a heavy chain, and a light chain. It is identified as one of the multifaceted protease-processing machines, having been shown to function beyond its role as a non-specific lysosomal protease.
Application
Cathepsin C has been used in a study that demonstrated the potential of a proteomics approach to identify novel proteins expressed by extravillous trophoblast and to uncover the mechanisms leading to disease states in pregnancy. Cathepsin C has also been used in a study to evaluate biodegradable thermogels.
The enzyme from Sigma has been used in the activation of granzyme k (Gzmk) precursor from E. coli. Granzymes are granule-stored lymphocyte serine proteases that are implicated in T- and natural killer cell-mediated cytotoxic defense reactions.
Cathepsin C from bovine spleen has been used for the in vitro enzyme activity assays. It has also been used as a digestion enzyme for in vitro myelin oligodendrocyte glycoprotein (MOG) digestion.
Biochem/physiol Actions
Cathespin C is a dipeptidyl aminopeptidase that can sequentially remove dipeptides from a peptide chain with an unsubstituted N-terminus. The enzyme exhibits a preference for glycine and proline as N-terminal aminoacids. Substrates that have an N-terminal lysyl or arginyl residue, or a penultimate proryl residue are not targeted by this enzyme. The endopeptidase activity requires the presence of halide ions and sulfydryl activators.
Cathepsin C (Cat C) serves as the physiological activator of groups of serine proteases within immune and inflammatory cells, playing a crucial role in the defense mechanisms of an organism. It may play a role in chronic airway diseases such as asthma. Cat C also acts as a protease link between inflammation and thrombosis.
Cat C participates in neutrophil recruitment and production of chemokines and cytokines in many inflammatory diseases. Cathepsin C plays a crucial role as an essential enzyme in activating granule serine proteases in cytotoxic T lymphocytes, natural killer cells (granzymes A and B), mast cells (chymase and tryptase), and neutrophils (cathepsin G, proteinase 3, and elastase).
Physical form
Lyophilized from a 1 M sodium chloride solution.
Other Notes
One unit will produce 1 μmole of Gly-Phe-NHOH from Gly-Phe-NH₂ and hydroxylamine per min at pH 6.8 at 37 °C using DL-phenylalanine hydroxamic acid as the standard. In addition to its hydrolytic properties, cathepsin C catalyzes the polymerization of dipeptide amides.
Disclaimer
Unstable. Keep frozen.
