• Purity

  >95%, by SDS-PAGE under reducing conditions and visualized by silver stain

• Endotoxin Level

  <0.01 EU per 1 μg of the protein by the LAL method.  

• Activity

  Measured in a cell proliferation assay using Balb/3T3 mouse embryonic fibroblast cells. Rubin, J.S.     et al. (1991) Proc. Natl. Acad. Sci. USA     88:415. The ED    ₅₀ for this effect is 100-500 ng/mL.

• Source

  E. coli-derived Leu54-Ala104, with an N-terminal Met

• Accession #

• N-terminal Sequence    
  Analysis

  Met

• Predicted Molecular Mass

  6 kDa

• SDS-PAGE

  5.5 kDa, reducing conditions

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: Epigen

Epigen (EPGN) is an epithelial mitogen that belongs to the EGF superfamily (1 ‑ 3). Human Epigen cDNA encodes a 154 amino acid (aa) residue type I transmembrane precursor glycoprotein with a 22 aa signal peptide, an 88 aa extracellular domain, a 21 aa transmembrane domain and a 23 aa cytoplasmic domain (2, 3). The extracellular domain (aa 23 ‑ 110) contains a pattern of six cysteines typical of EGF family proteins (1 ‑ 3). Potential splice variants of 133, 112, 103, 94 or 73 aa, lacking either N‑terminal sequence (aa 15 or 36 to 44), transmembrane and juxtamembrane sequence (aa 87 or 96 to 137), or sequences in both regions, have been described (4). In addition to potentially secreted splice variants, Epigen is among several EGF family proteins that can undergo metalloproteinase cleavage to generate a soluble form (3, 5). Cleavage of Epigen by TACE/ADAM17 has been demonstrated (5). The mature, shed form of human Epigen (aa 54 ‑ 104) shares 92%, 94% and 94% aa sequence identity with mouse, rat and equine Epigen, respectively, and more than 40% aa identity with corresponding regions of TGF‑ alpha and epiregulin (2). Epigen mRNA is found in many tissues, but it is mainly expressed in actively proliferating cells within these tissues. For example, Epigen in skin is found mainly in the proliferating root sheath of hair follicles, and transgenic overexpression in the skin causes hyperplasia in sebaceous glands (3, 6). Epigen is also expressed developmentally and by invasive adenocarcinomas of the breast and prostate (3). Epigen is strongly mitogenic for epithelial cells and fibroblasts, despite its relatively weak affinity for its main receptor, ErbB1 (2, 3). The mitogenic potential of Epigen is enhanced by its unusually long persistence on the membrane before ubiquitylation and receptor‑mediated depletion (3).

• References:

1. Schneider, M.R. and E. Wolf (2010) J. Cell. Physiol. 218:460.

2. Strachan, L. et al. (2001) J. Biol. Chem. 276:18265.

3. Kochupurakkal, B.S. et al. (2005) J. Biol. Chem. 280:8503.

4. SwissProt Accession # Q6UW88.

5. Sahin, U. and C.P. Blobel 2007) FEBS Lett. 581:41.

6. Dahlhoff, M. et al. (2010) J. Invest. Dermatol. 130:623.

• Entrez Gene IDs:

  255324 (Human); 71920 (Mouse)

• Alternate Names:

  EPGN; Epigen