CST3, also known as Cystatin-C is a member of family 2 of the cystatin superfamily. This protein is a secreted type 2 cysteine protease inhibitor synthesized in all nucleated cells, has been proposed as a replacement for serum creatinine for the assessment of renal function, particularly to detect small reductions in glomerular filtration rate. It is involved in processes such as tumor invasion and metastasis, inflammation and some neurological diseases. It inhibits many cysteine proteases such as papain and cathepsins B, H, K, L and S. It indicates that a murine model should be relevant for studies of the human disease, hereditary Cystatin C amyloid angiopathy. Source: Recombinant protein corresponding to aa21-140 from mouse CST3, fused to His-Tag at C-terminal, expressed in insect cell. Molecular Weight: ~14.2kD (126aa) confirmed by MALDI-TOF 13.5-18kD (SDS-PAGE under reducing conditions.) Endotoxin: <1EU/1ug (determined by LAL method) Biological Activity: The IC50 value is <1nM. 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 25C. Amino Acid Sequence: ATPKQGPRML GAPEEADANE EGVRRALDFA VSEYNKGSND AYHSRAIQVV RARKQLVAGV NYFLDVEMGR TTCTKSQTNL TDCPFHDQPH LMRKALCSFQ IYSVPWKGTH SLTKFSCKNA HHHHHH Storage and Stability: May be stored at 4C for short-term only. Aliquot to avoid repeated freezing and thawing.. Store at -20C. Aliquots are stable for 6 months after receipt at -20C. For maximum recovery of product, centrifuge the original vial after thawing and prior to removing the cap. Further dilutions can be made in assay buffer.
