Introduction
Leukemia Inhibitory Factor (LIF) is a protein that plays a crucial role in maintaining embryonic stem cells. It prevents these cells from spontaneously changing into other cell types. LIF also has other functions, including aiding in the development of nerve cells that use acetylcholine, regulating stem cell versatility, influencing bone and fat metabolism, stimulating the growth of certain cell lines, and boosting the production of megakaryocytes (cells that produce platelets). The LIF proteins in humans and mice share a 78% similarity in their amino acid sequence.
Description
Recombinant Murine Leukemia Inhibitory Factor (LIF) is a single-chain protein produced in E. coli bacteria. It is not glycosylated, meaning it lacks attached sugar molecules. It comprises 181 amino acids and has a molecular weight of 20 kDa. The purification process utilizes specialized chromatographic methods to ensure its purity.
Physical Appearance
Sterile white powder obtained by freeze-drying.
Formulation
The Leukemia Inhibitory Factor (LIF) was freeze-dried from a sterile solution with a concentration of 1mg/ml. The solution contained 20mM Phosphate buffer with a pH of 7.4 and 0.02% Tween-20.
Solubility
To reconstitute the freeze-dried Leukemia Inhibitory Factor (LIF), it is advised to dissolve it in sterile water to a minimum concentration of 100µg/ml. This solution can be further diluted using other aqueous solutions.
Stability
While the lyophilized (freeze-dried) Leukemia Inhibitory Factor (LIF) remains stable at room temperature for up to 3 weeks, it is best stored in a dry environment below -18°C. Once reconstituted, store Leukemia Inhibitory Factor (LIF) at 4°C for a maximum of 7 days. For extended storage, freeze at -18°C. The addition of a carrier protein such as HSA or BSA (0.1%) is recommended for long-term storage. Avoid repeated freezing and thawing cycles.
Purity
The purity is confirmed to be higher than 95.0% through the following analyses: (a) RP-HPLC (Reverse Phase High-Performance Liquid Chromatography), and (b) SDS-PAGE (Sodium Dodecyl Sulfate-Polyacrylamide Gel Electrophoresis).
Biological Activity
The biological activity of murine LIF is evaluated using the M1 cell differentiation assay. The activity is determined to be less than 0.01 ng/ml, which translates to a specific activity of 100,000,000 IU/mg. The definition of a standard of 50 units is the LIF concentration in 1.0 mL of cell culture medium that triggers the differentiation of 50% of M1 colonies.
Synonyms
CDF, HILDA, D-FACTOR, Differentiation- stimulating factor, Melanoma-derived LPL inhibitor, MLPLI, Emfilermin, Leukemia inhibitory factor, LIF, DIA.
Amino Acid Sequence
MSPLPITPVNATCAIRHPCHGNLMNQIKNQLAQLNGSANALFISYYTAQGEPFP
NNVEKLCAPNMTDFPSFHGNGTEKTKLVELYRMVAYLSASLTNITRDQKVLNP
TAVSLQVKLNATIDVMRGLLSNVLCRLCNKYRVGHVDVPPVPDHSDKEAFQR
KKLGCQLLGTYKQVISVVVQAF.
