| Description : |
IL-21 is a pleiotropic cytokine produced by CD4+ T cells in response to antigenic stimulation. Its action generally enhances antigen-specific responses of immune cells. The biological effects of IL-21 include induction of differentiation of T-cells-stimulated B-cells into plasma cells and memory B-cells, stimulation (in conjuction) with IL-4 of IgG production, and induction of apoptotic effects in naïve B-cells and stimulated B-cells in the absence of T-cell signaling. Additionally, IL-21 promotes the anti-tumor activity of CD8+ T-cells and NK cells. IL-21 exerts its effect through binding to a specific type I cytokine receptor, IL-21R, which also contains the gamma chain (γc) found in other cytokine receptors including IL-2, IL-4, IL-7, IL-9 and IL-15. The IL-21/IL-21R interaction triggers a cascade of events which includes activation of the tyrosine kinases JAK1 and JAK3, followed by activation of the transcription factors STAT1 and STAT3. |
| Source : |
E. coli |
| Species : |
Rat |
| Form : |
Sterile Filtered White lyophilized (freeze-dried) powder. |
| Bio-activity : |
Measured by its ability to inhibit IL21dependent proliferation of N1186 human T cells. The ED50 for this effect is typically 1-5 μg/mL in the presence of 50 ng/mL of recombinant mouse IL21. |
| Molecular Mass : |
Approximately 15.2 kDa, a single non-glycosylated polypeptide chain containing 129 amino acids. |
| Protein Length : |
129 |
| AA Sequence : |
HKSSPQRPDHLLIRLRHLMDIVEQL KIYENDLDPELLTAPQDVKGQCEHE AFACFQKAKLKPSNTGNNKTFINDL LAQLRRRLPAKRTGNKQRHMAKCPS CDLYEKKTPKEFLERLKWLLQKMIH QHLS |
| Endotoxin : |
Less than 1 EU/μg of rRtIL-21 as determined by LAL method. |
| Purity : |
>95% by SDS-PAGE and HPLC analyses. |
| Storage : |
This lyophilized preparation is stable at 2-8 centigrade, but should be kept at -20 centigrade for long term storage, preferably desiccated. Upon reconstitution, the preparation is stable for up to one week at 2-8 centigrade. For maximal stability, apportion the reconstituted preparation into working aliquots and store at -20 to -70 centigrade. Avoid repeated freeze/thaw cycles. |
| Storage Buffer : |
Lyophilized from a 0.2mm filtered concentrated solution in PBS, pH 7.4 |
| 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 centigrade. Further dilutions should be made in appropriate buffered solutions. |
