Interleukin 33 (IL-33) is a member of the IL-1 family that potently drives production of T helper-2 (Th2)-associated cytokines (e.g., IL-4). IL33 is a ligand for ST2 (IL1RL1), an IL-1 family receptor that is highly expressed on Th2 cells, mast cells and group 2 innate lymphocytes. It is expressed by a wide variety of cell types, including fibroblasts, mast cells, dendritic cells, macrophages, osteoblasts, endothelial cells, and epithelial cells.

Sequence: 
MSIQGTSLLTQSPASLSTYNDQSVSFVLENGCYVINVDDSGKDQEQDQVLLRYYESPCPASQSGDGVDGKKLMVNMSPIKDTDIWLHAND
KDYSVELQRGDVSPPEQAFFVLHKKSSDFVSFECKNLPGTYIGVKDNQLALVEEKDESCNNIMFKLSKI with polyhistidine tag at the C-terminus

Source:
Escherichia coli

Endotoxin Test:
<0.1 EU per 1 μg of the protein by the LAL method. Activity:
Measure by its ability to induce proliferation in D10.G4.1 cells. The ED₅₀ for this effect is <40 pg/mL. The specific activity of recombinant mouse IL-33 is > 2 x 10⁷ IU/mg.

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

Formulation:
The protein was lyophilized from a solution containing 1X PBS, pH 7.4.

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. Upon reconstitution, protein aliquots should be stored at -20°C or -80°C.

Note:
Please use within one month after protein reconstitution.

Data Sheet