Recombinant Human Cathepsin B Protein, CF

• Reactivity: Hu
• Applications: Enzyme Activity
• Format: Carrier-Free

Recombinant Human Cathepsin B Protein, CF Summary

• Details of Functionality: Measured by its ability to cleave the fluorogenic peptide substrate Z-LR-AMC (Catalog # ES008). The specific activity is >2,500 pmol/min/µg, as measured under the described conditions.
• Source: Mouse myeloma cell line, NS0-derived human Cathepsin B protein
  Arg18-Ile339 (pro) & Phe74-Ile339 (mature), both with a C-terminal 10-His tag
• Accession #: P07858
• N-terminal Sequence: Arg18 & Phe74
• Structure / Form: Pro and Mature forms
• Protein/Peptide Type: Recombinant Enzymes
• Gene: CTSB
• Purity: >95%, by SDS-PAGE under reducing conditions and visualized by silver stain
• Endotoxin Note: <1.0 EU per 1 μg of the protein by the LAL method.

Applications/Dilutions

• Dilutions:
  • Enzyme Activity
• Theoretical MW: 37 kDa (Pro) & 29 kDa (Mature).
  Disclaimer note: The observed molecular weight of the protein may vary from the listed predicted molecular weight due to post translational modifications, post translation cleavages, relative charges, and other experimental factors.
• SDS-PAGE: 43 kDa and 36 kDa, reducing conditions

Packaging, Storage & Formulations

• Storage: Use a manual defrost freezer and avoid repeated freeze-thaw cycles.
  • 6 months from date of receipt, -20 to -70 °C as supplied.
  • 3 months, -20 to -70 °C under sterile conditions after opening.
• Buffer: Supplied as a 0.2 μm filtered solution in Tris and NaCl.
• Purity: >95%, by SDS-PAGE under reducing conditions and visualized by silver stain
• Assay Procedure:
  • Activation Buffer: 25 mM MES, 5 mM DTT, pH 5.0
  • Assay Buffer: 25 mM MES,0.02% Brij-35, pH 5.0
  • Recombinant Human Cathepsin B (rhCathepsin B) (Catalog # 953-CY)
  • Fluorogenic Peptide Substrate VII: Z-Leu-Arg-AMC (Catalog # ES008)
  • Black 96-well Plate
  • Plate Reader with Fluorescence Read Capability
  1. Dilute rhCathepsin B to 10 µg/mL in Activation Buffer.
  2. Incubate at room temperature for 15 minutes.
  3. Dilute rhCathepsin B to 0.1 µg/mL in Assay Buffer.
  4. Dilute substrate to 80 µM in Assay Buffer.
  5. Load 50 µL of the 0.1 µg/mL rhCathepsin B in a black well plate, and start the reaction by adding 50 µL of 80 µM Substrate. Include a Substrate Blank containing 50 µL Assay Buffer and 50 µL of 80 µM Substrate.
  6. Read at excitation and emission wavelengths of 380 nm and 460 nm (top read), respectively, in kinetic mode for 5 minutes.
     Calculate specific activity:

  Specific Activity (pmol/min/µg) = (Adjusted Vmax* (RFU/min) x Conversion Factor** (pmol/RFU)) / (amount of enzyme (µg))

  *Adjusted for Substrate Blank

  **Derived using calibration standard 7-Amino, 4-Methyl Coumarin (AMC).

  Per Well:
  • rhCathepsin B: 0.005 µg
  • Substrate: 40 µM

Notes

This product is produced by and ships from R&D Systems, Inc., a Bio-Techne brand.

Alternate Names for Recombinant Human Cathepsin B Protein, CF

• APP secretase
• APPS
• Cathepsin B
• Cathepsin B1
• CPSBamyloid precursor protein secretase
• CTSB
• cysteine protease
• EC 3.4.22
• EC 3.4.22.1

Background

Cathepsin B is the first described member of the family of lysosomal cysteine proteases (1). Cathepsin B possesses both endopeptidase and exopeptidase activities, in the latter case acting as a peptidyl-dipeptidase. It is known to process a number of proteins, including pro and active caspases, prorenin and secretory leucoprotease inhibitor (SLPI) (2-4). Therefore, Cathepsin B may play a role in activation and inactivation of caspases, activation of renin and inactivation of SLPI, the key steps in apoptosis, angiotensin production, and progression of emphysema, respectively. Because of its increased levels and redistribution of the enzyme in human and animal tumors, Cathepsin B may also have role in invasion and metastasis (5).

In addition to lysosome, Cathepsin B can be secreted or associated with plasma membrane, cytoplasm, and nucleus. It 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 (1).

1. Mort, J.S. (2004) in Handbook of Proteolytic Enzymes. Barrett, A.J. et al. (eds): Academic Press, San Diego, p. 1079.
2. Vancompernolle, K. et al. (1998) FEBS Lett. 438:150.
3. Jutras, I. and T.L. Reudelhuber (1999) FEBS Lett. 443:48.
4. Taggart, C.C. et al. (2001) J. Biol. Chem. 276:33345.
5. Bergquin, I.M. and B.F. Sloane (1996) Adv. Exp. Med. Biol. 389:281.

Publications for Cathepsin B (953-CY)(19)

Publications using 953-CY

• Sung, Y;Choi, Y;Park, SM;Choi, N;Lee, S;Suh, SB;Kim, C;Hur, W;Cho, SW;Lee, D;Ryu, JH; Fluorescence-guided tumor resection with a cathepsin B-activatable, EGFR-targeted probe and a dual-mode surgical exoscope European journal of medicinal chemistry 2025-08-30 [PMID: 40911969] (Bioassay, Human)
• Biswas, M;Sengupta, S;Gandhi, KA;Gupta, SK;Gera, PB;Nayak, BS;Jagadeb, M;Gota, V;Sonawane, A; Engineered L-asparaginase variants with enhanced therapeutic properties to improve treatment of childhood acute lymphatic leukemia Cancer gene therapy 2025-07-30 [PMID: 40739000] (Bioassay, Human)
• Kim, J;Song, S;Gwak, M;Cho, H;Yun, WS;Hwang, N;Kim, J;Lee, JS;Kim, DH;Kim, H;Jeon, SI;Kim, TI;Kim, K; Micro-syringe chip-guided intratumoral administration of lipid nanoparticles for targeted anticancer therapy Biomaterials research 2023-10-16 [PMID: 37845762] (Bioassay, N/A)
• W Deng, Y Bai, F Deng, Y Pan, S Mei, Z Zheng, R Min, Z Wu, W Li, R Miao, Z Zhang, TS Kupper, J Lieberman, X Liu Streptococcal pyrogenic exotoxin B cleaves GSDMA and triggers pyroptosis Nature, 2022-02-02;0(0):. 2022-02-02 [PMID: 35110732] (Bioassay, Human)
• Y Wu, HT Whittaker, S Noy, K Cleverley, V Brault, Y Herault, EMC Fisher, FK Wiseman The effects of Cstb duplication on APP/amyloid-beta pathology and cathepsin B activity in a mouse model PLoS ONE, 2021-07-22;16(7):e0242236. 2021-07-22 [PMID: 34292972] (ELISA Standard, Human)
• Bharani Thangavelu, Angela M. Boutté Single Molecule Assay for Ultrasensitive Detection of Cathepsin B in Human Blood ACS Omega 2021-04-13 [PMID: 33869941] (ELISA Standard, Human)
• S Adem, S Jain, M Sveiven, X Zhou, AJ O'Donoghue, DA Hall Giant magnetoresistive biosensors for real-time quantitative detection of protease activity Sci Rep, 2020-05-14;10(1):7941. 2020-05-14 [PMID: 32409675] (Bioassay, Human)
• RA Høglund, SB Torsetnes, A Lossius, B Bogen, EJ Homan, R Bremel, T Holmøy Human Cysteine Cathepsins Degrade Immunoglobulin G In Vitro in a Predictable Manner Int J Mol Sci, 2019-09-29;20(19):. 2019-09-29 [PMID: 31569504] (Bioassay, Human)
• D Huo, J Zhu, G Chen, Q Chen, C Zhang, X Luo, W Jiang, X Jiang, Z Gu, Y Hu Eradication of unresectable liver metastasis through induction of tumour specific energy depletion Nat Commun, 2019-07-11;10(1):3051. 2019-07-11 [PMID: 31296864] (Bioassay, Human)
• NDP Leguizamón, EM Rodrigues, ML de Campos, AVB Nogueira, KS Viola, VK Schneider, DM Neo-Justin, M Tanomaru-F, WF Zambuzzi, F Henrique-S, A Soares-Cos, G Faria, JA Cirelli In vivo and in vitro anti-inflammatory and pro-osteogenic effects of citrus cystatin CsinCPI-2 Cytokine, 2019-06-18;123(0):154760. 2019-06-18 [PMID: 31226439] (Bioassay, Human)
• CW Lee, JN Stankowski, J Chew, CN Cook, YW Lam, S Almeida, Y Carlomagno, KF Lau, M Prudencio, FB Gao, M Bogyo, DW Dickson, L Petrucelli The lysosomal protein cathepsin L is a progranulin protease Mol Neurodegener, 2017-07-25;12(1):55. 2017-07-25 [PMID: 28743268] (Bioassay, Human)
• BM Larimer, E Wehrenberg, F Dubois, A Mehta, T Kalomeris, K Flaherty, G Boland, U Mahmood Granzyme B PET Imaging as a Predictive Biomarker of Immunotherapy Response Cancer Res., 2017-05-01;77(9):2318-2327. 2017-05-01 [PMID: 28461564] (Bioassay)
• Shivanna V, Kim Y, Chang K Endosomal acidification and cathepsin L activity is required for calicivirus replication. Virology, 2014-08-09;464(0):287-95. 2014-08-09 [PMID: 25108379] (Bioassay, Mouse)
• Jiang H, Cheng X, Shi G, Hu L, Inoue A, Yamamura Y, Wu H, Takeshita K, Li X, Huang Z, Song H, Asai M, Hao C, Unno K, Koike T, Oshida Y, Okumura K, Murohara T, Kuzuya M Cathepsin K-mediated Notch1 activation contributes to neovascularization in response to hypoxia. Nat Commun, 2014-06-04;5(0):3838. 2014-06-04 [PMID: 24894568] (Bioassay, Mouse)
• Bruchard M, Mignot G, Derangere V, Chalmin F, Chevriaux A, Vegran F, Boireau W, Simon B, Ryffel B, Connat J, Kanellopoulos J, Martin F, Rebe C, Apetoh L, Ghiringhelli F Chemotherapy-triggered cathepsin B release in myeloid-derived suppressor cells activates the Nlrp3 inflammasome and promotes tumor growth. Nat Med, 2012-12-02;19(1):57-64. 2012-12-02 [PMID: 23202296] (Surface Plasmon Resonance, Human)
• Guery L, Benikhlef N, Gautier T, Paul C, Jego G, Dufour E, Jacquel A, Cally R, Manoury B, Vanden Berghe T, Vandenabeele P, Droin N, Solary E Fine-tuning nucleophosmin in macrophage differentiation and activation. Blood, 2011-08-29;118(17):4694-704. 2011-08-29 [PMID: 21876121] (Enzyme Assay, Human)
• Burster T, Marin-Esteban V, Boehm BO, Dunn S, Rotzschke O, Falk K, Weber E, Verhelst SH, Kalbacher H, Driessen C Design of protease-resistant myelin basic protein-derived peptides by cleavage site directed amino acid substitutions. Biochem. Pharmacol., 2007-08-02;74(10):1514-23. 2007-08-02 [PMID: 17803968] (Enzyme Assay, Human)
• Cheng T, Hitomi K, van Vlijmen-Willems IM, de Jongh GJ, Yamamoto K, Nishi K, Watts C, Reinheckel T, Schalkwijk J, Zeeuwen PL Cystatin M/E is a high affinity inhibitor of cathepsin V and cathepsin L by a reactive site that is distinct from the legumain-binding site. A novel clue for the role of cystatin M/E in epidermal cornification. J. Biol. Chem., 2006-03-24;281(23):15893-9. 2006-03-24 [PMID: 16565075] (Enzyme Assay, Human)
• Gocheva V, Zeng W, Ke D, Klimstra D, Reinheckel T, Peters C, Hanahan D, Joyce JA Distinct roles for cysteine cathepsin genes in multistage tumorigenesis. Genes Dev., 2006-02-15;20(5):543-56. 2006-02-15 [PMID: 16481467] (Enzyme Assay, Human)

Bioinformatics

• Gene Symbol: CTSB
• Uniprot:
  • P07858()