CST3 Rat

Cystatin C is a secreted protein with a molecular weight of approximately 14 kDa . The recombinant form of rat Cystatin C is typically produced in a mouse myeloma cell line (NS0) and includes a C-terminal 6-His tag for purification purposes . The protein sequence of rat Cystatin C consists of 140 amino acids, starting from Met1 to Ala140 .

Cystatin C is ubiquitously expressed in human tissues and body fluids . Its primary function is to inhibit cysteine proteases, which are enzymes that degrade proteins by cleaving peptide bonds. By inhibiting these proteases, Cystatin C helps regulate protein turnover and prevent excessive proteolysis, which can lead to tissue damage .

The inhibitory activity of Cystatin C is measured by its ability to inhibit the cleavage of a fluorogenic peptide substrate by papain, a model cysteine protease . The IC50 value, which represents the concentration of Cystatin C required to inhibit 50% of the protease activity, is less than 15 nM . This high affinity for cysteine proteases underscores its effectiveness as a protease inhibitor.

Cystatin C levels in the serum are closely correlated with the glomerular filtration rate (GFR), making it a valuable biomarker for kidney function . Elevated levels of Cystatin C are associated with an increased risk of coronary artery disease and cardiovascular events . Additionally, its expression and activity can be influenced by various physiological and pathological conditions, including inflammation and cancer .

Recombinant rat Cystatin C is widely used in research to study its role in various diseases and to develop therapeutic strategies targeting cysteine proteases. It is also utilized in enzyme-linked immunosorbent assays (ELISAs) to quantify Cystatin C levels in biological samples .