Interleukin-4 (IL-4), also known as B cell-stimulatory factor-1, is a monomeric, approximately 13 kDa ‑ 18 kDa Th2 cytokine that shows pleiotropic effects during immune responses. It is a glycosylated polypeptide that contains three intrachain disulfide bridges and adopts a bundled four alpha -helix structure. IL-4 is primarily expressed by Th2-biased CD4+ T cells, mast cells, basophils, and eosinophils. It promotes cell proliferation, survival, and immunoglobulin class switch to IgG4 and IgE in human B cells, acquisition of the Th2 phenotype by naïve CD4+ T cells, priming and chemotaxis of mast cells, eosinophils, and basophils, and the proliferation and activation of epithelial cells.

Expressed in E.coli with total 159 AA. Mw: 18.5 KDa (calculated).

N-terminal 6xHis-tag and TEV cleavage site, 25 extra AA (highlighted).

Recombinant antigen for research use or manufacturing only.

MSYYHHHHHHDYDIPTTENLYFQGAMGSGIHKCDITLQEIIKTLNSLTEQKTLCTELTVTDIFAASKNTTEKETFCRAATVLRQFYSHHEKDTRCLGATAQQFHRHKQLIRFLKRLDRNLWGLAGLNSCPVKEANQSTLENFLERLKTIMREKYSKCSS

Store lyophilized protein at –20°C. Aliquot reconstituted protein and store at –80°C.  Avoid repeated freezing/thawing cycles.

Add deionized water to prepare a working stock solution of approximately 1 mg/mL and let thelyophilized pellet dissolves completely.

BCA to determine quantity of the protein.

SDS PAGE to determine purity of the protein.

Lyophilized at 1 mg/mL in NaCl 500mM, KCl 2.7mM, Na2HPO4 10mM, KH2PO4 1.8mM, pH 7.0.

ELISA and Western Blotting.