LIF is a pleiotrophic factor produced by multiple cell types, including T cells, myelomonocytic lineages, fibroblasts, liver, heart and melanoma. LIF promotes long-term maintenance of embryonic stem cells by suppressing spontaneous differentiation. Other activities include the stimulation of acute phase protein synthesis by hepatocytes, stimulation of differentiation of cholinergic nerves, and suppression of adipogenesis by inhibiting the lipoprotein lipase in adipocytes. While human LIF is active on mouse cells and is widely used in the maintenance of murine ESC to prevent spontaneous differentiation, mouse LIF is not active on human cells due to its inability to bind to the human LIF receptor. Recombinant mouse LIF is a 19.9kD protein containing 180 amino acids residues, including three disulfide bonds. Recombinant protein corresponding to mouse Leukemia inhibitory factor, expressed in E. coli. Molecular Weight: ~19.6kD (180aa) Biological Activity: The ED50 as determined by the M1 cell differentiation assay is 0.05ng/ml, corresponding to a specific activity of 2x10e7 units/mg. Amino Acid Sequence: SPLPITPVNA TCAIRHPCHG NLMNQIKNQL AQLNGSANAL FISYYTAQGE PFPNNVEKLC APNMTDFPSF HGNGTEKTKL VELYRMVAYL SASLTNITRD QKVLNPTAVS LQVKLNATID VMRGLLSNVL CRLCNKYRVG HVDVPPVPDH SDKEAFQRKK LGCQLLGTYK QVISVVVQAF Storage and Stability: Lyophilized and reconstituted products are stable for 6 months after receipt at -20C. Reconstitute with sterile ddH2O, 0.1% BSA or HSA. Aliquot to avoid repeated freezing and thawing. Store at -20C. For maximum recovery of product, centrifuge the original vial after thawing and prior to removing the cap. Further dilutions can be made in assay buffer.
