Cystatin C: Proteins and Enzymes

Cystatin C is a secreted cysteine protease inhibitor that inhibits Cathepsins B, H, K, L, and S. Cystatin C serum concentration correlates closely to the glomerular filtration rate (GFR); elevated levels are associated with coronary artery and cardiovascular disease risk. Dysregulation of Cystatin C can modulate tumor growth and metastasis. In humans, the L68Q variant forms dimers and oligomers more easily than wild type protein and is the cause for hereditary Cystatin C amyloid angiopathy.