Cystatin C

A 120-amino acid endogenous protein that potently inhibits cysteine proteases, used as a laboratory standard and research tool in enzymology.

Length: 120 amino acids
Half-life: Reported clearance half-time is approximately 2 hours in physiological systems.
Mechanism: Cystatin C is a potent, reversible inhibitor of endogenous cysteine proteases, such as cathepsins B, H, K, L, and S.
Studied in: It is used as a laboratory standard and research tool to study the role of cysteine proteases in various biological processes, including protein degradation and tissue remodeling.

About Cystatin C

Cystatin C is a non-glycosylated, basic protein consisting of 120 amino acids, produced by all nucleated cells. It belongs to the type 2 cystatin superfamily of cysteine protease inhibitors. Its primary biological function is the regulation of protease activity through potent, tight, and reversible binding to the active sites of target enzymes.

In the laboratory, recombinant Cystatin C is a valuable reagent. It is used as a specific inhibitor to dissect the roles of cysteine proteases (e.g., cathepsins) in cellular pathways like antigen presentation and extracellular matrix turnover. It also serves as a well-characterised standard for immunoassays and other analytical methods developed to quantify its levels in biological samples.

Laboratory notes

Cystatin C is a potent endogenous inhibitor of cysteine proteases like cathepsins.
In clinical chemistry, its concentration in serum is used as a biomarker for certain analytical purposes.
As a research reagent, it is used to block cysteine protease activity in cell lysates or conditioned media to prevent unwanted protein degradation.

Storage and reconstitution basics: storage guide.

Questions about Cystatin C

What is the primary molecular function of Cystatin C?

Cystatin C is a competitive, reversible inhibitor of papain-like cysteine proteases, including a wide range of mammalian cathepsins (B, H, K, L, S).

Is Cystatin C a peptide?

While composed of amino acids, its size (120 residues, ~13.3 kDa) places it in the category of a small protein rather than a peptide, which is typically defined as being under 50 amino acids.

Why is Cystatin C used as a research tool?

Its specific and potent inhibition of a class of proteases makes it an excellent tool for enzymology studies and for preventing the degradation of proteins of interest by cysteine proteases during in vitro experiments.

Is Cystatin C for human use?

No. It is supplied strictly for in-vitro laboratory research and is not for human or animal consumption.

Related research peptides

All products are sold for laboratory research use only. Not for human consumption, not a medicine, not for diagnosing, treating or preventing any condition.