Cathepsin K Protein, Mouse (His)

Cathepsin K protein is a thiol protease that is critical in osteoclastic bone resorption and exhibits potent endoprotease activity against fibrinogen under acidic conditions. Its potential role in extracellular matrix degradation is noteworthy. Cathepsin K Protein, Mouse (His) is the recombinant mouse-derived Cathepsin K protein, expressed by E. coli , with N-6*His labeled tag.

Cathepsin K Protein, a thiol protease, is integral to osteoclastic bone resorption and exhibits potent endoprotease activity against fibrinogen under acidic conditions. Additionally, it may play a significant role in extracellular matrix degradation (By similarity). Notably, Cathepsin K is involved in the release of thyroid hormone thyroxine (T4) through limited proteolysis of TG/thyroglobulin in the thyroid follicle lumen, as demonstrated by studies. This dual functionality underscores its importance in bone metabolism and extracellular matrix dynamics, as well as its specific involvement in the regulated release of thyroid hormones.

Measured by its ability to cleave the fluorogenic peptide substrate, Z-Gly-Pro-Arg-MCA.The specific activity is 1949.534 pmol/min/µg, as measured under the described conditions.

Materials
Assay buffer: 50 mmol/L Tris-HCL, pH 7.5
Cathepsin K Protein, Mouse (His) (HY-P72157)
Substrate：Z-Gly-Pro-Arg-AMC
Standard：7-Amino-4-methylcoumarin (AMC, HY-D0027)

Procedure
1. Standard curve: Dilute AMC to 0, 1.5625, 3.125, 6.25, 12.5, 25, 50 μmol/L with assay buffer, at the excitation and emission wavelengths of 380 nm and 460 nm, respectively, and make a standard curve with the measured RFU as the abscissa, and the amount of the standard substance as the abscissa, to obtain the standard curve formula.
2. 0.1 μg/mL of Mouse Cathepsin K was prepared in assay buffer.
3. 0.1 μmol/L of the substrate Z-Gly-Pro-Arg-AMC was prepared with assay buffer.
4. 150 μL of 0.1 μg/mL Mouse Cathepsin K was taken and 75 μL of assay buffer and 75 μL of 0.1 μmol/L substrate were added.
Blank wells: no Mouse Cathepsin K was added and the reaction volume was replenished using assay buffer.
5. Incubate at 37°C for 5 min.
6. Detect at excitation and emission wavelengths of 380 nm and 460 nm, respectively.
7. Calculate the specific activity:

Mouse

E. coli

N-6*His

P55097 (V115-M329)

13038  [NCBI]

Full Length of Mature Protein

VPDSIDYRKKGYVTPVKNQGQCGSCWAFSSAGALEGQLKKKTGKLLALSPQNLVDCVTENYGCGGGYMTTAFQYVQQNGGIDSEDAYPYVGQDESCMYNATAKAAKCRGYREIPVGNEKALKRAVARVGPISVSIDASLASFQFYSRGVYYDENCDRDNVNHAVLVVGYGTQKGSKHWIIKNSWGESWGNKGYALLARNKNNACGITNMASFPKM

Approximately 31 kDa

Greater than 90% as determined by reducing SDS-PAGE.

Lyophilized powder

1.Lyophilized from a 0.22 μm solution of 10 mM Tris-HCl, 1 mM EDTA, 6% Trehalose, pH 8.0.
2.Lyophilized from a 0.22 μm solution of PBS, 6% Trehalose, pH 7.4.
Note: For SPR assay, please replace the buffer. Primary amine components (e.g., Tris, imidazole) can affect protein-coupled chips.

<1 EU/μg, determined by LAL method.

It is not recommended to reconstitute to a concentration less than 100 μg/mL in ddH₂O.

Stored at -20°C for 2 years from date of receipt. After reconstitution, it is stable at 4°C for 1 week or -20°C for longer (with carrier protein). It is recommended to freeze aliquots at -20°C or -80°C for extended storage.

Room temperature in continental US; may vary elsewhere.