Interleukin-4 (IL-4) is a pleiotropic cytokine that has many biological roles, including the stimulation of activated B-cell and T-cell proliferation, and the differentiation of naive helper T-cell to Th2 cells. Interleukin-4 is a co-stimulator of DNA-synthesis and is induces the expression of class II MHC molecules on resting B-cells. It also enhances both secretion and cell surface expression of IgE and IgG1. Recombinant Interleukin-4 protein, fused to His-tag at N-terminus, was expressed in E. coli and was purified by conventional chromatography techniques, after refolding of the isolated inclusion bodies in a renaturation buffer. AA Sequence: MGSSHHHHHH SSGLVPRGSH MHKCDITLQE IIKTLNSLTE QKTLCTELTV TDIFAASKNT TEKETFCRAA TVLRQFYSHH EKDTRCLGAT AQQFHRHKQL IRFLKRLDRN LWGLAGLNSC PVKEANQSTL ENFLERLKTI MREKYSKCSS Endotoxin Level: 1.0 EU per 1 ug of protein (determined by LAL method) Biological activity: The ED50 for this effect is <1.8ng/ml. Measured in a cell proliferation assay using TF1 human erythroleukemic cells. Storage and Stability: May be stored at 4C for short-term only. For long-term storage, store at -20C. Aliquots are stable for at least 6 months 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.
