IL-4 is a pleiotropic cytokine produced by activated T cells. It is a potent lymphoid cell growth factor, which stimulates the growth and survivability of certain B-cells and T-Cells. IL-4 is a ligand of the interleukin 4 receptor that also binds to IL-13 – which may contribute to many overlapping functions of this cytokine and IL-13. STAT6, a signal transducer and activator of transcription, has been shown to play a central role in mediating the immune regulatory signal of this cytokine. IL-3, IL-4, IL-5, IL-13, and CSF2 form a cytokine gene cluster on chromosome 5q, with the IL-4 gene particularly close to IL-13. IL-4, IL-13 and IL-5 are found to be regulated coordinately by several long-range regulatory elements in an over 120 kilobase range on the chromosome. Two alternatively spliced transcript variants of this gene encoding distinct isoforms have been reported.
Human Interleukin-4 (rHu IL-4) is a 15 kDa single, non-glycosylated polypeptide chain containing 130 amino acid residues. It has been purified using proprietary chromatographic techniques.
|Molecular Mass||15 kDa|
|Specific Activity||>5 x 10⁶ IU/mg|
|Biological Activity||Recombinant human IL-4 is fully biologically active when compared to standards.The specific biological activity was determined by a standard cell proliferation assay using a human factor-dependent cell line TF-1. The ED₅₀ for this effect is <0.20 ng/ml, corresponding to a specific activity of 5 x 10⁶ units/mg.|
|Formulation||Lyophilized from sterile-filtered (0.20 µm), concentrated protein solution (1 mg/ml) in PBS (pH 7.40) with no additives.|
|Reconstitution||Please Note: Always centrifuge product briefly before opening vial. The lyophilized protein should be reconstituted with distilled, sterile water to a concentration of 0.10 – 1 mg/ml. For further dilution, carrier protein (0.10% BSA or HSA) should be added to avoid loss of bioactivity.|
|Purity||Greater than 98% as determined by SDS-PAGE and HPLC analysis.|
|Endotoxin Level||< 0.10 ng per µg rHu IL-4 (1EU/µg).|
|Stability & Storage||The lyophilized powder, though stable at room temperature for up to 3 weeks, is best stored desiccated at -20°C. Reconstituted rHu IL-4 should be used immediately or stored long-term in undiluted working aliquots at -20°C. For long-term storage it is recommended to add a carrier protein (0.10% endotoxin-free HSA or BSA; e.g. Cat.No. C-69500A). Avoid repeated freeze-thaw cycles.|