• Purity

  >97%, by SDS-PAGE visualized with Silver Staining and quantitative densitometry by Coomassie? Blue Staining.

• Endotoxin Level

  <0.10 EU per 1 μg of the protein by the LAL method.  

• Activity

  Measured by its ability to induce Smad2 phosphorylation in P19 mouse embryonal carcinoma cells. Yeo, C.     et al. (2001) Mol. Cell.     7:949. Approximately 100 ng/mL of Recombinant Human Nodal can effectively induce Smad2 phosphorylation.

• Source

  E. coli-derived His238-Leu347, with an N-terminal Met

• Accession #

• N-terminal Sequence    
  Analysis

  Met

• Structure / Form

  Disulfide-linked homodimer

• Predicted Molecular Mass

  12.9 kDa (monomer)

Carrier Free

What does CF mean?

CF stands for Carrier Free (CF). We typically add Bovine Serum Albumin (BSA) as a carrier protein to our recombinant proteins. Adding a carrier protein enhances protein stability, increases shelf-life, and allows the recombinant protein to be stored at a more dilute concentration. The carrier free version does not contain BSA.

What formulation is right for me?

In general, we advise purchasing the recombinant protein with BSA for use in cell or tissue culture, or as an ELISA standard. In contrast, the carrier free protein is recommended for applications, in which the presence of BSA could interfere.

Background: Nodal

Nodal is a 13 kDa member of the TGF-beta superfamily of molecules (1-3). Its name derives from the fact that it is expressed in the primitive node of the developing embryo. In human, it is synthesized as a 347 amino acid (aa) preproprecursor that contains a 26 aa signal sequence, a 211 aa prodomain, and a 110 aa mature region (4, 5). Consistent with its TGF-beta superfamily membership, it exists as a disulfide-linked homodimer and would be expected to demonstrate a cysteine-knot motif (1, 5, 6). Mature human Nodal is 99%, 98%, 96% and 98% aa identical to mature canine, rat, bovine and mouse Nodal, respectively. Nodal signals through two receptor complexes, both of which contain members of the TGF-beta family of Ser/Thr kinase receptors. The first receptor complex is composed of ActRIB/ALK4 and ActRIIB. Nodal interaction with the ligand-binding subunit ALK4 requires the participation of fucosylated Cripto, a member of the EGF-CFC gene family. The second complex is composed of ALK7 and ActRIIB, and does not require Cripto interaction (7-9). Nodal signaling is regulated by a number of inhibitors. Nodal is reported to form nonsignaling disulfide-linked heterodimers with BMP-3, -4 and -7 (2, 6). There are also at least three secreted factors that block Nodal activation of its receptor. The first is Cerberus, a member of the DAN family of proteins. The last two are TGF-beta family members named Lefty-A and B (2, 11). The exact mechanisms employed are unclear, but Leftys are apparently induced by nodal and can work at a considerable distance from their origin (2). Nodal is known to induce both mesoderm and endoderm, participate in anterior-posterior positioning, and through ALK7, induce apoptosis in susceptible cell populations (2, 8, 12).

• References:

1. Kishigami, S. and Y. Mishina (2005) Cytokine Growth Factor Rev. 16:265.

2. Schier, A.F. (2003) Annu. Rev. Cell Dev. Biol. 19:589.

3. Whitman, M. and M. Mercola (2001) Sci. STKE. Jan 9;(64):RE1.

4. Gebbia, M. et al. (1997) Nat. Genet. 17:305.

5. Hart, A.H. et al. (2005) Biochem. Biophys. Res. Commun. 333:1361.

6. Yeo, C-Y. and M. Whitman (2001) Mol. Cell 7:949.

7. Yan, Y-T. et al. (2002) Mol. Cell. Biol. 22:4439.

8. Munir, S. et al. (2004) J. Biol. Chem. 279:31277.

9. Shen, M.M. and A.F. Schier (2000) Trends Genet. 16:303.

10. Lah, M. et al. (1999) Genomics 55:364.

11. Kosaki, K. et al. (1999) Am. J. Hum. Genet. 64:712.

12. Zhou, X. et al. (1993) Nature 361:543.

• Entrez Gene IDs:

  4838 (Human); 18119 (Mouse)

• Alternate Names:

  BMP-16; MGC138230; nodal homolog (mouse); nodal homolog; Nodal; nodal, mouse, homolog