Feline Cystatin C Recombinant Protein

The cystatin superfamily is made up of several proteins that contain multiple cystatin-like sequences. Some of the members are cysteine protease inhibitors, while others have lost, or never gained, this inhibitory activity. There are three inhibitory families in the cystatin superfamily, including the type 1 cystatins (stefins), type 2 cystatins, and the kininogens. The type 2 cystatin proteins, including Cystatin C, are a class of cysteine proteinase inhibitors found in a variety of human fluids and secretions. They appear to provide protective functions. As an inhibitor of lysosomal cysteine proteinases, Cystatin C plays a critical role in many diverse processes. Cystatin C is a specific biomarker of kidney function and can be used as a marker of renal complications in COVID-19. It is the most abundant extracellular inhibitor of cysteine proteases and can be found in high concentrations in many biological fluids. It is expressed in virtually all organs of the body. A mutation in Cystatin C has been associated with amyloid angiopathy. Expression of Cystatin C in vascular wall smooth muscle cells is severely reduced in both atherosclerotic and aneurysmal aortic lesions, establishing its role in vascular disease. In addition, this protein has been shown to have an antimicrobial function, inhibiting the replication of herpes simplex virus.

Felis catus (domestic cat), Lynx canadensis (Canada lynx), Lynx pardinus (Spanish lynx), Lynx rufus (bobcat), Prionailurus bengalensis (leopard cat), Prionailurus viverrinus (fishing cat)