Recombinant Human Interleukin-13, Variant

Accession P35225

GeneID 3596

Source Escherichia coli.

Molecular Weight Approximately 12.3 kDa, a single non-glycosylated polypeptide chain containing 112 amino acids, with a substitution of Q for R at position 112 compared with the wild type IL-13.

Quantity 2µg/10µg/1mg

AA Sequence GPVPPSTALR ELIEELVNIT QNQKAPLCNG SMVWSINLTA GMYCAALESL INVSGCSAIE KTQRMLSGFC PHKVSAGQFS SLHVRDTKIE VAQFVKDLLL HLKKLFREGQ FN

Purity > 97 % 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 0.5 ng/ml, corresponding to a specific activity of > 2.0 × 106 IU/mg.

Physical Appearance Sterile Filtered White lyophilized (freeze-dried) powder.

Formulation Lyophilized from a 0.2 µm filtered concentrated solution in PBS, pH 7.2, with 5 % trehalose.

Endotoxin Less than 1 EU/µg of rHuIL-13, Variant as determined by LAL method.

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.

Stability & Storage Use a manual defrost freezer and avoid repeated freeze-thaw cycles.

- 12 months from date of receipt, -20 to -70 °C as supplied.

- 1 month, 2 to 8 °C under sterile conditions after reconstitution.

- 3 months, -20 to -70 °C under sterile conditions after reconstitution.

Usage This material is offered by Shanghai PrimeGene Bio-Tech for research, laboratory or further evaluation purposes. NOT FOR HUMAN USE.

Reference 1. Schmutz J, Martin J, Terry A, et al. 2004. Nature, 431: 268-74.

2. Wynn TA. 2003. Annu Rev Immunol, 21: 425-56.

3. Heinzmann A, Mao XQ, Akaiwa M, et al. 2000. Hum Mol Genet, 9: 549-59.

4. Wang M, Xing ZM, Lu C, et al. 2003. Hum Genet, 113: 387-90.

Background Human Interleukin-13 (IL-13) is expressed by the IL13 gene located on the chromosome 5. IL-13 is a 132 amino acid protein containing a proposed 20 amino acid signal peptide, and shares approximately 30% amino acid sequence homology to human IL-4. Additionally, the two cytokines exhibit overlapping biological activities. Human IL-13 is produced by activated Th0, Th1-like Th2-like and CD8 T cells. Similarly to IL-4, IL-13 has multiple effects on the differentiation and functions of monocytes/macrophages. IL-13 can suppress the cytotoxic functions of monocytes/macrophages. IL-13 variant is a natural variant of IL-13 and has a Q instead of R112 of wild type, which associated with increased risk for asthma development and at homozygosity associated with higher levels of serum total IgE in some allergic rhinitis patients.