• Purity

  >90%, 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 inhibit LIF-dependent proliferation of TF‑1 human erythroleukemic cells. Kitamura, T.     et al. (1989) J. Cell Physiol.     140:323. The ED    ₅₀ for this effect is 3-10 µg/mL in the presence of 0.3 ng/mL of recombinant human LIF.

• Source

  Spodoptera frugiperda,     Sf 21 (baculovirus)-derived Gln45-Ser833

• Accession #

• N-terminal Sequence    
  Analysis

  No results obtained: Gln45 predicted

• Predicted Molecular Mass

  89 kDa

• SDS-PAGE

  100-110 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: LIF R alpha

The activities of the pleiotropic cytokine LIF are mediated through a high-affinity heterodimeric receptor complex consisting of two membrane glycoproteins: an alpha subunit (LIF R alpha, also known as LIF R beta and CD118) that binds LIF with low affinity and the 130 kDa (gp130) subunit that does not bind LIF by itself, but is required for high-affinity binding of LIF by the complex. The gp130 subunit was first described as the signal transducing subunit of the high-affinity IL-6 receptor complex. Besides LIF, the high-affinity heterodimeric LIF receptor complex has been shown to mediate the activities of oncostatin M (OSM), cardiotrophin-1 and ciliary neurotrophic factor (CNTF).

Human LIF R alpha  cDNA encodes a 1097 amino acid (aa) residue precursor type I membrane protein with a 44 aa residue signal peptide, a 789 aa residue extracellular domain, a 26 aa residue transmembrane domain, and a 238 aa residue cytoplasmic domain. LIF R alpha is a member of the cytokine receptor family and has extensive homology to gp130. The extracellular domain of LIF R alpha  has two cytokine receptor domains and three fibronectin type III repeats. In mouse, mRNAs encoding a soluble LIF R alpha and lacking transmembrane and intracellular domains, have been isolated. Soluble LIF R alpha has been shown to bind LIF and has LIF antagonistic activity.

• References:

1. Bazan, J.F. (1990) Proc. Natl. Acad. Sci. USA 87:6934.

2. Gearing, D.P. (1994) Guidebook to Cytokines and Their Receptors, Academic Press, p130.

3. Pennica D. et al. (1995) J. Biol. Chem. 270:10915.

• Long Name:

  Leukemia Inhibitory Factor Receptor alpha

• Entrez Gene IDs:

  3977 (Human); 16880 (Mouse); 81680 (Rat)

• Alternate Names:

  CD118 antigen; CD118; FLJ98106; FLJ99923; leukemia inhibitory factor receptor alpha; leukemia inhibitory factor receptor; LIF R alpha; LIF R beta; LIF receptor; LIFR; LIF-R; LIFRa; SJS2; STWS; SWS