Recombinant Human Dkk-1 N-Terminal Fragment Protein, CF

When Recombinant Human Dkk-1 N-Terminal Fragment (Catalog #9837-DK) is immobilized at 1 μg/mL, 100 μL/well, Recombinant Mouse CKAP4/p63 (Catalog # 9734-CK) binds with an ED50 of 9-54 ng/mL.

• Reactivity: Hu
• Applications: Bioactivity
• Format: Carrier-Free

Recombinant Human Dkk-1 N-Terminal Fragment Protein, CF Summary

• Details of Functionality: Measured by its binding ability in a functional ELISA. When Recombinant Human Dkk‑1 N-Terminal Fragment is coated at 1 μg/mL, Mouse CKAP4/p63 (Catalog # 9734-CK) binds with an ED₅₀ of 9-54 ng/mL.
• Source: Chinese Hamster Ovary cell line, CHO-derived human Dkk-1 protein
  Thr32-Ser141, with a C-terminal 6-His tag
• Accession #: O94907
• N-terminal Sequence: Thr32, Ser35 & Ser39
• Protein/Peptide Type: Recombinant Proteins
• Purity: >95%, by SDS-PAGE visualized with Silver Staining and quantitative densitometry by Coomassie® Blue Staining.
• Endotoxin Note: <0.10 EU per 1 μg of the protein by the LAL method.

Applications/Dilutions

• Dilutions:
  • Bioactivity
• Theoretical MW: 12 kDa.
  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: 13 - 21 kDa, reducing conditions

Packaging, Storage & Formulations

• Storage: Use a manual defrost freezer and avoid repeated freeze-thaw cycles.
  • 12 months from date of receipt, -20 to -70 °C as supplied.
  • 1 month, 2 to 8 °C under sterile conditions after reconstitution.
  • 3 months, -20 to -70 °C under sterile conditions after reconstitution.
• Buffer: Lyophilized from a 0.2 μm filtered solution in PBS.
• Purity: >95%, by SDS-PAGE visualized with Silver Staining and quantitative densitometry by Coomassie® Blue Staining.
• Reconstitution Instructions: Reconstitute at 500 μg/mL in PBS.

Notes

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

Alternate Names for Recombinant Human Dkk-1 N-Terminal Fragment Protein, CF

• dickkopf (Xenopus laevis) homolog 1
• dickkopf homolog 1 (Xenopus laevis)
• dickkopf related protein-1
• Dickkopf-1
• dickkopf-related protein 1
• Dkk1
• Dkk-1
• hDkk-1
• SKdickkopf-1 like

Background

Dickkopf related protein 1 (Dkk-1) is the founding member of the Dickkopf family of proteins that includes Dkk-1, -2, -3, -4, and a related protein, Soggy (1, 2). Dkk proteins are secreted proteins that contain two conserved cysteine-rich domains (CRDs), CRD1 (N-terminal) and CRD2 (C-terminal), separated by a linker region. Each domain contains ten cysteine residues (1-3). Mature human Dkk-1 is a 40 kDa glycosylated protein. Within the N-terminal fragment [amino acids (aa) 32-141] that includes the CRD1, human DKK-1 shares 85% aa sequence identity with mouse Dkk-1. Dkk-1 antagonizes Wnt/beta-catenin signaling, an activity for which the C-terminal CRD2 is both necessary and sufficient (4, 5), while the N-terminal CRD1 was required for binding to CKAP4 (6). However, crystallographic studies have shown that Dkk-1 interacts with LRP-6 as a bipartite inhibitor, with both CRDs binding the extracellular domain of LRP-6 simultaneously (7-9).  Dkk-1/LRP-6/Krm2 complex internalization has been shown to down-regulate Wnt signaling (4, 10). Dkk-1 is expressed throughout development and antagonizes Wnt-7a during limb development (11, 12). Other sites of expression include developing neurons, hair follicles, and the retina (13, 14). The balance between Wnt signaling and Dkk-1 inhibition is critical for bone formation and homeostasis (15). Insufficient or excess Dkk-1 activity in bone results in increased or decreased bone density, respectively (13, 16). In adults, Dkk-1 is expressed in osteoblasts and osteocytes, and neurons. Cerebral ischemia induces Dkk-1 expression, which contributes to neuronal cell death (17). Dkk-1 also likely has a complex role in cancer, as it has been shown to act as a tumor suppressor and also to promote metastasis (18-20).

1. Krupnik, V.E. et al. (1999) Gene 238:301.
2. Niehrs, C. (2006) Oncogene 25:7469.
3. Bullock, C.M. et al. (2004) Mol. Pharmacol. 65:582.
4. Mao, B. et al. (2001) Nature 411:321.
5. Brott, B.K. and S.Y. Sokol (2002) Mol. Cell. Biol. 22:6100.
6. Kimura, H. et al. (2016) J. Clin. Invest. 126:7.
7. Chen, S. et al. (2011) Dev. Cell 21:848.
8. Bourhis, E. et al. (2011) Structure 19:1433.
9. Cheng, Z. et al. (2011) Nat. Struct. Mol. Biol. 18:1204.
10. Mao, B. et al. (2002) Nature 417:664.
11. Kemp, C. et al. (2005) Dev. Dyn. 233:1064.
12. Adamska, M. et al. (2004) Dev. Biol. 272:134.
13. Li, J. et al. (2006) Bone 39:754.
14. Verani, R. et al. (2007) J. Neurochem. 100:242.
15. Pinzone, J.J. et al. (2009) Blood 113:517.
16. Morvan, F. et al. (2006) J. Bone Miner. Res. 21:934.
17. Cappuccio, I. et al. (2005) J. Neurosci. 25:2647.
18. Menezes, M.E. et al. (2012) Int. J. Cancer 130:1477.
19. Li, S. et al. (2013) PLoS One 8:e84944.
20. Chen, L. et al. (2013) Mol. Cancer 12:157.

Bioinformatics

• Uniprot:
  • O94907()