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Recombinant Human Cathepsin B /CTSB Protein, His Tag, 2x 500 µg  

Recombinant Human Cathepsin B /CTSB Protein, His Tag, 2x 500 µg

Recombinant Human Cathepsin B /CTSB Protein, Arg 18 - Ile 339, produced in human 293 cells (HEK293), His tag

Synonym
recombinant, human, protein, cathepsin, CTSB, CPSB, APPS

More details

CTB-H5222-1K

Availability: within 7 days

1 980,00 €

Background
Cathepsin B (CTSB) also known as APP secretase (APPS) and CPSB, is an enzymatic protein belonging to the peptidase C1 family. Cathepsin B / CTSB is synthesized as a preproenzyme. Following removal of the signal peptide, the inactive proenzyme undergoes further modifications including removal of the pro region to result in the active enzyme. The catalytic activity of Cathepsin B / APPS contains: Hydrolysis of proteins with broad specificity for peptide bonds; Preferentially cleaves -Arg-Arg-|-Xaa bonds in small molecule substrates (thus differing from cathepsin L); In addition to being an endopeptidase, shows peptidyl-dipeptidase activity, liberating C-terminal dipeptides. As a thiol protease, cathepsin B / CPSB is believed to participate in intracellular degradation and turnover of proteins and has also been implicated in tumor invasion and metastasis. Overexpression of cathepsin B has been associated with esophageal adenocarcinoma and other tumors.

Source
Recombinant Human Cathepsin B, His Tag (CTB-H5222) is expressed from human 293 cells (HEK293). It contains AA Arg 18 - Ile 339 (Accession # P07858-1 (L26V)).
Predicted N-terminus: Arg 18 & Leu 80

Molecular Characterization
This protein carries a polyhistidine tag at the C-terminus. The Human Cathepsin B will be further processed into mature form (Leu 80-Ile 339). The protein has a calculated MW of 36.7 kDa (pro-form) and 29.5 kDa (mature-form). The protein migrates as 42-50 kDa and 34 kDa under reducing (R) condition (SDS-PAGE) due to glycosylation.

Endotoxin
Less than 1.0 EU per μg of the rhCTSB by the LAL method.

Purity
>95% as determined by SDS-PAGE.

Formulation
Lyophilized from 0.22 μm filtered solution in 50 mM Tris, 150 mM NaCl, pH8.0. Normally trehalose is added as protectant before lyophilization.

Reconstitution
See Certificate of Analysis for details of reconstitution instruction and specific concentration.

Storage
Avoid repeated freeze-thaw cycles.
No activity loss was observed after storage at:
In lyophilized state for 1 year (4°C-8°C); After reconstitution under sterile conditions for 1 month (4°C-8°C) or 3 months (-20°C to -70°C).

Bioactivity
Measured by its ability to cleave the fluorogenic peptide substrate Z-LR-AMC. Measured in 100μl reaction mixture containing 25 mM MES, pH 5.0, 0.01 µg rhCathepsin B, 10 µM reaction substrate.

The specific activity is >2800 pmol/min/µg.

References

(1) Basrur V., et al., 2003, J. Proteome Res. 2:69-79.
(2) Chi A., et al., 2006, J. Proteome Res. 5:3135-3144.
(3) Royer-Zemmour B., et al., 2008, Hum. Mol. Genet. 17:3617-3630.
(4) Cao L., et al., 1994, Gene 139 (2): 163–9.