CST4 (Cystatin-S) belongs to the cystatin family. The cystatin superfamily encompasses proteins that contain multiple cystatin-like sequences. Some of the members are active cysteine protease inhibitors, while others have lost or perhaps never acquired this inhibitory activity. This protein strongly inhibits papain and ficin, partially inhibits stem bromelain and bovine cathepsin C, but does not inhibit porcine cathepsin B or clostripain. Papain is inhibited non-competitively.
Source:
Recombinant corresponding to aa21-141 from human CST4, fused to His-tag at N-terminus, expressed in E.coli.
Molecular Weight:
~16.8kD (145aa) confirmed by MALDI-TOF
AA Sequence:
MGSSHHHHHH SSGLVPRGSH MGSMSSSKEE NRIIPGGIYD ADLNDEWVQR ALHFAISEYN KATEDEYYRR PLQVLRAREQ TFGGVNYFFD VEVGRTICTK SQPNLDTCAF HEQPELQKKQ LCSFEIYEVP WEDRMSLVNS RCQEA
Storage and Stability:
May be stored at 4 degrees C for short-term only. Aliquot to avoid repeated freezing and thawing. Store at -20 degrees C. Aliquots are stable for 6 months at -20 degrees C. 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.