| 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. |
| 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, pH7.2, with 5% trehalose. |
| Endotoxin: |
Less than 1 EU/µg of rHuIL-13, Variant as determined by LAL method. |
| Reconstitution: |
Centrifuge the vial briefly before opening to ensure that the contents settle at the bottom. Reconstitute the vial with sterile distilled water or an aqueous buffer containing 0.1% BSA to achieve a concentration of 0.1-1.0 mg/mL. Divide the resulting stock solution into working aliquots and store them at or below -20°C. For further dilutions, use 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. |
| Background: |
The IL13 gene on chromosome 5 is responsible for producing Human Interleukin-13 (IL-13), a cytokine of 132 amino acids with a 20 amino acid signal peptide and about 30% sequence homology with IL-4. IL-13, secreted by various T cell subsets, mirrors IL-4 in its biological functions, influencing monocyte/macrophage differentiation and inhibiting their cytotoxic activities. A variant of IL-13, differing by one amino acid, is linked to a higher asthma risk and elevated IgE levels in certain allergic individuals. |
