Cystatins are a superfamily of cysteine proteinase inhibitors found in both plants and animals. They comprise a group of proteinase inhibitors, widely distributed in tissues and body fluids, and form tight complexes with cysteine proteases such as cathepsin B, H, L and S. Cystatin C, a secreted molecule of this family, is of interest from biochemical, medicine and evolutionary points of view. Cystatin C, with molecular weight of 13260 Da, is composed of 120 amino acids, lacks carbohydrate and has two disulfide bridges located near the carboxyl terminus. Cystatin C is increased in patients with malignant diseases, and is related to the insufficiency of renal function and appears to be a better marker than creatinine. On the other hand, low levels of cystatin C involve cause the breakdown of the elastic laminae and, subsequently, the atherosclerosis and abdominal aortic aneurysm.
Cystatin-C Human Recombinant produced in E.Coli is a single, non-glycosylated, Polypeptide chain containing 129 amino acids and having a molecular mass of 14.5 kDa. The protein contains an extra His tag at N-terminus. The Cystatin-C amino acid sequence is identical to UniProtKB/Swiss-Prot entry Q6FGW9 amino acids 28�146.The Cystatin-C is purified by proprietary chromatographic techniques.
