Cystatin-C, Cystatin-3, Neuroendocrine basic polypeptide, Gamma-trace, Post-gamma-globulin, CST3, MGC117328.
Cystatin C is part to the cystatin protein family, which has members with various cystatin-like sequences. Part of the proteins has the ability to act as active cysteine protease inhibitors, other members has lost or never had the ability. Three sub members of the cystatin protein family are the type 1 cystatins, type 2 cystatins & kininogens. The locus in chromosome twenty holds the most type 2 cystatin genes. Cystatin C can be found in the cystatin locus, it is the most common extracellular inhibitor of cysteine proteases, that is available in big volumes in biological fluids and exist in every tissue in the body.
CST3 Human Recombinant produced in E.Coli is a single, non-glycosylated polypeptide chain containing 141 amino acids (27-146 a.a.) and having a molecular mass of 15.6kDa.
CST3 is fused to a 21 amino acid His tag at N-Terminus and purified by proprietary chromatographic techniques.
The CST3 solution (0.25mg/1ml) contains 0.1M NaCl, 20mM Tris-HCl buffer (pH 8.0) and 20% glycerol.
For long term storage it is recommended to add a carrier protein (0.1% HSA or BSA).
Avoid multiple freeze-thaw cycles.
Greater than 95.0% as determined by SDS-PAGE.
The IC50 value is < 2.0nM. The inhibitory function of Cystatin 3 on protease activity of papain was measured by a fluorometric assay using Z-FR-AMC at pH 7.5 at 25˚C.
Amino acid sequence
MGSSHHHHHH SSGLVPRGSH MSSPGKPPRL VGGPMDASVE EEGVRRALDF AVGEYNKASN DMYHSRALQV VRARKQIVAG VNYFLDVELG RTTCTKTQPN LDNCPFHDQP HLKRKAFCSF QIYAVPWQGT MTLSKSTCQD A