Mouse interleukin 13 (mIL-13) is a pleiotropic cytokine produced by activated Th2 cells. IL-13 induces B cell proliferation and immunoglobin production.It contains a four helical bundle with two internal disulfide bonds. Mouse IL13 shares 58% sequence identity with human protein and exhibits cross-species activity.

IL13 signals via receptor IL13R(type2,IL4R) and activates STAT-6. IL13 initially binds IL-13Rα1 with low affinity and triggers association of IL4Rα,generating a high affinity heterodimeric receptor IL13R and eliciting downstream signals. IL13 also binds IL-13Rα2 with high affinity which plays a role in a negative feedback system of IL13 siganling. IL13 is an important mediator of allergic inflammation and disease.

·Description
Recombinant mouse IL-13 produced in E. coli is a single, non-glycosylated, polypeptide chain containing 106 amino acids and having a molecular mass of 11.5kDa.

·Quality Control
Biological activity: The ED50 of rmIL13 as determined by dose-dependent stimulation of proliferation of TF-1 human erythroleukemic cells was < 2ng/ml, corresponding to a Specific Activity of 5.0 x 105 IU/mg.
Purity: Greater than 98.0% as determined by:
(a) Analysis by RP-HPLC.
(b) Analysis by reducing and non-reducing SDS-PAGE Silver Stained gel.
Amino-Acid Sequence: The sequence of the first five N-terminal amino acids was determined to be Ser-Val-Ser-Leu-Pro.
Endotoxin: Less than 0.1ng/μg (IEU/μg) of rmIL-13.

·Formulation
Sterile and Lyophilized with no additives.

·Reconstitution
It is recommended to reconstitute the lyophilized rmIL-13 in sterile 18MΩ-cm H2O not less than 100μg/ml, which can then be further diluted to other aqueous solutions.

·Storage
Lyophilized rmIL-13 although stable at room temperature for 3 weeks, should be stored desiccated below -18°C. Upon reconstitution rmIL-13 should be stored at 4°C between 2-7 days and aliquots of reconstituted samples are stable up to 3 months below -18°C for future use.

Please avoid freeze-thaw cycles.