Synonyms
Interleukin-4, IL-4, BSF-1, BCDF, IL4E12, Pitrakinra
Description
Interleukin-4 (IL-4), also known as B cell-stimulatory factor-1, is a pleiotropic cytokine that induces differentiation of naive helper T cells (Th0 cells) to Th2 cells and produced by by mast cells, activated T cells and bone marrow stromal cells. Mature human IL-4 shares 55%, 39% and 43% aa sequence identity with bovine, mouse, and rat IL-4, respectively.It is a potent cytokine produced by T cells and to a lesser extent by tumor-associated natural killer cells, basophils, and mast cells. IL-4 is a differentiation factor for transforming growth factor-beta secreting Th3. And IL-4 activates two distinct signalling pathways through tyrosine phosphorylation of Stat6, a signal transducer and activator of transcription, and of a 170K protein called 4PS.
Molecular Weight
Approximately 15.0 kDa.
AA sequence
HKCDITLQEI IKTLNSLTEQ KTLCTELTVT DIFAASKNTT EKETFCRAAT VLRQFYSHHE KDTRCLGATA QQFHRHKQLI RFLKRLDRNL WGLAGLNSCP VKEANQSTLE NFLERLKTIM REKYSKCSS
Appearance
Sterile Filtered White lyophilized (freeze-dried) powder.
Purity
> 98% by SDS-PAGE and HPLC analyses.
Biological Activity
Fully biologically active when compared to standard. The ED50 as determined by a cell proliferation assay using human TF-1 cells is less than 0.2 ng/mL, corresponding to a specific activity of > 5.0 × 106 IU/mg.
Endotoxin
< 1.0 EU per 1μg of the protein by the LAL method.
Formulation
Lyophilized from a 0.2 μm filtered concentrated solution in PBS, pH 7.4.
Reconstitution
We recommend that this vial be briefly centrifuged prior to opening to bring the contents to the bottom. Reconstitute in sterile distilled water or aqueous buffer containing 0.1% BSA to a concentration of 0.1-1.0 mg/mL. Stock solutions should be apportioned into working aliquots and stored at ≤ -20°C. Further dilutions should be made in appropriate buffered solutions.