The interleukin-4 (IL-4) is a cytokine that induces differentiation of naive helper T cells (Th0 cells) to Th2 cells. Upon activation by IL-4, Th2 cells subsequently produce additional IL-4 in a positive feedback loop. The cell that initially produces IL-4, thus inducing Th2 differentiation, has not been identified, but recent studies suggest that basophils may be the effector cell. It is closely related and has functions similar to IL-13.

Sequence:
MHKCDITLQEIIKTLNSLTEQKTLCTELTVTDIFAASKNTTEKETFCRAATVLRQFYSHHEKDTRCLGATAQQFHRHKQLIRFLKRLDRNLWGL
AGLNSCPVKEANQSTLENFLERLKTIMREKYSKCSS with polyhistidine tag at the C-terminus

Source:
Escherichia coli
Animal-free reagent and laboratory
Manufactured and tested under GMP guideline

Endotoxin level:
<0.1 EU per 1 μg of the protein by the LAL method. Activity:
Measure by its ability to induce TF-1 cells proliferation. The ED₅₀ for this effect is <0.2 ng/mL. The specific activity of recombinant human IL-4 is approximately >2.8 x 10⁷ IU/mg.

Purity:
>98% as determined by SDS-PAGE. Purified by Ni-NTA chromatography.

Formulation:
The protein was lyophilized from a solution containing 1X PBS, pH 8.0.

Reconstitution:
It is recommended to reconstitute the lyophilized protein in sterile H₂O to a concentration not less than 100 μg/mL and incubate the stock solution for at least 20 min to ensure sufficient re-dissolved.

Storage:
Lyophilized protein should be stored at -20°C. This product is stable for one year upon receipt, when handled and stored as instructed. Upon reconstitution, protein aliquots should be stored at -20°C or -80°C. Avoid repeated freeze/thaw cycles.

Note:
Please use within one month after protein reconstitution.

Specification:
Croyez GMP® recombinant proteins are manufactured in ISO 13485:2016 and GMP-certified facility.
The processes include:
● Testing and traceability of raw material
● Records of the maintenance and equipment calibration
● Personnel training records
● Batch-to-batch consistency
● Documentation of QA control and process changes
● Manufactured and tested under an ISO 13485:2016 certified quality management system
● Stability monitor of product shelf-life

Reference:
1. Junttila IS. (2018) Front Immunol. 9: 888.
2. Ho IC, Miaw SC. (2016) Adv Exp Med Biol. 941: 31‐77.
3. Brown MA, Hural J. (2017) Crit Rev Immunol. 37,2-6: 181-212.
4. Luzina, IG. et al. (2012) J Leukoc Biol. 92,4: 753-64.

Data Sheet