Description: Cathepsin G, Human, Peptide
Cathepsin G (CG) is a serine protease originating from human neutrophils. Serine proteases are a class of proteases with the amino acid serine as the key residue of their enzymatic center, which initiates the proteolytic cleavage of specific target proteins, the protease substrates. CG is, together with neutrophil elastase (NE), and proteinase 3 (PR3), involved in bacterial defense. For instance CG is crucial for resistance against infection with Staphylococcus aureus and contributes to protection against several fungal infections. In addition, CG mediates (together with NE and PR3) regulatory functions that shape the inflammatory response. Once released in the extracellular environment, CG is able to proteolytically modify chemokines such as CXCL5 and CCL15 thereby increasing their chemotactic activity. CG has also been implicated in the processing of pro-form of interleukin-1 to its active form, to degrade mature TNF and inactivate IL-6. Given the prominent role in inflammation, CG is involved in the pathophysiology of several serious human inflammatory diseases, such as chronic obstructive pulmonary disease (COPD), Crohn's disease, rheumatoid arthritis, cystic fibrosis and other conditions clinically manifested by excessive inflammatory reactions.