- Other Names
- Leukemia inhibitory factor, HILDA (human interleukin in DA cells), MLPLI (melanoma-derived LPL inhibitor), DIA (differentiation-inducing factor)
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Leukemia inhibitory factor (LIF) is a 20 kD protein that belongs to the IL-6 receptor family. It binds to a heterodimeric membrane receptor made up of a LIF-specific subunit, gp190 or LIFR, and the subunit gp130, which is shared with the other members of the IL-6 family. The LIF complex receptor signals though STAT3 and JAK kinases. LIF expression has been observed in various tissues including thymus, lung, and neuronal tissue. LIF displays diverse biological effects but is best known for its ability to inhibit the differentiation of embryonic stem cells in mice and contribute to stem cell self-renewal. Human and mouse LIF share 79% sequence homology and exhibit cross-species activity. However, LIF inhibition of stem cell differentiation appears to be mouse specific. It is involved in the induction of hematopoietic differentiation in normal and myeloid leukemia cells, induction of neuronal cell differentiation, regulation of mesenchymal to epithelial conversion during kidney development, and may also have a role in immune tolerance at the maternal-fetal interface. Alternatively spliced transcript variants encoding multiple isoforms have been observed for this gene. LIF can be upregulated by pro-inflammatory cytokines such as TNF-α and IL-17, and elevated levels of LIF have been found in cases of rheumatoid arthritis, neural injury, systemic inflammation, and tuberculosis.Product Details
- Human LIF, amino acids (Ser23-Phe202) (Accession# NP_002300.1), was expressed in E. coli.
- Molecular Mass
- The 180 amino acid recombinant protein has a predicted molecular mass of 19.6 kD. The predicted N-terminal amino acid is Ser.
- >98%, as determined by Coomassie stained SDS-PAGE and HPLC analysis.
- Lyophilized, carrier-free.
- Endotoxin Level
- Less than 0.1 ng per µg of protein.
- Storage & Handling
- Unopened vial can be stored at -20°C or -70°C. For maximum results, quick spin vial prior to opening. Reconstitute in water to a concentration of 0.1-1.0 mg/ml. Do not vortex. It is recommended to further dilute in a buffer, such as 5% Trehalose, and store working aliquots at -20°C to -80°C. Avoid repeated freeze/thaw cycles.
- ED50 is ≤ 0.1 ng/ml, corresponding to a specific activity of ≥ 1.0 x 107 units/mg as determined by the dose-dependent stimulation of the proliferation of human TF-1 cells.
- Expressed in the trophectoderm of the developing embryo, activated CD4+ T cells.
- Inhibits embryonic stem cell differentiation, induces the terminal differentiation of myeloid leukemia cells. LIF is upregulated by TNF-α and IL-17. LIF is downregulated by IL-4 and IL-13 in fibroblasts.
- Embryonic stem cells.
- LIFR complex (gp190 and gp130).
- Human LIF induces proliferation of TF-1 cells.
- Cell Type
- Hematopoietic stem and progenitors, Embryonic Stem Cells
- Biology Area
- Cell Biology, Immunology, Stem Cells
- Molecular Family
- Growth Factors, Cytokines/Chemokines
- Antigen References
1. Moreau JF, et al. 1988. Nature 336:690.
2. Tomida M, et al. 1993. FEBS Lett. 334:193.
3. Metcalfe SM. 2011. Genes Immun. 12:157.
4. Voyle RB, et al. 1999. Exp. Cell Res. 249:199.
5. Slaets H et al. 2010. Trends Mol. Med. 16:493.
6. Souza PP, et al. 2012. Mol. Immunol. 49:601.
- Gene ID
- 3976 View all products for this Gene ID
- View information about LIF on UniProt.org
- Does specific activity of a recombinant protein vary between lots?
Specific activity will vary for each lot and for the type of experiment that is done to validate it, but all passed lots will have activity within the established ED50 range for the product and we guarantee that our products will have lot-to-lot consistency. Please conduct an experiment-specific validation to find the optimal ED50 for your system.
- Have your recombinants been tested for stability?
Our testing shows that the recombinant proteins are able to withstand room temperature for a week without losing activity. In addition the recombinant proteins were also found to withstand four cycles of freeze and thaw without losing activity.
- How do you convert activity as an ED50 in ng/ml to a specific activity in Units/mg?
- Use formula Specific activity (Units/mg) = 10e6/ ED50 (ng/mL)
- How does the activity of your recombinant proteins compare to competitors?
We quality control each and every lot of recombinant protein. Not only do we check its bioactivity, but we also compare it against other commercially available recombinant proteins. We make sure each recombinant protein’s activity is at least as good as or better than the competition’s. In order to provide you with the best possible product, we ensure that our testing process is rigorous and thorough. If you’re curious and eager to make the switch to BioLegend recombinants, contact your sales representative today!
- What is the specific activity or ED50 of my recombinant protein?
The specific activity range of the protein is indicated on the product datasheets. Because the exact activity values on a per unit basis can largely fluctuate depending on a number of factors, including the nature of the assay, cell density, age of cells/passage number, culture media used, and end user technique, the specific activity is best defined as a range and we guarantee the specific activity of all our lots will be within the range indicated on the datasheet. Please note this only applies to recombinants labeled for use in bioassays. ELISA standard recombinant proteins are not recommended for bioassay usage as they are not tested for these applications.