| Description : |
Interleukin-21 (IL-21) belongs to the Type I four helix bundle cytokines, and shares the common cytokine receptor γ chain with IL-2, IL-4, IL-7, IL-9, and IL-15. IL-21 is expressed by CD4+ T cells, natural killer (NK) T cells, and Th17 cells, and the IL-21 receptor is highly expressed on CD4+ and CD8+ B cells; indeed, IL-21 plays a pivotal role in the survival and proliferation of B cells, and their differentiation to immunoglobulin (Ig) producing cells. IL-21 up-regulates and down-regulates the production of IgG1 and IgE by B cells, respectively, and diminishes the severity of allergy and asthma. In some case, IL-21 also induces the apoptosis of B cells. The other roles of IL-21 include regulation of innate immune systems, implication on autoimmunity, and antitumor actions. |
| Source : |
E. coli |
| Species : |
Human |
| Form : |
Sterile Filtered White lyophilized (freeze-dried) powder. |
| Bio-activity : |
ED50 < 0.5 ng/mL, measured by a cell growth inhibition assay using Mino cells, corresponding to a specific activity of > 2.0 × 10^6 units/mg. |
| Molecular Mass : |
15.4 kDa, observed by reducing SDS-PAGE. |
| Protein Length : |
132 |
| AA Sequence : |
MQDRHMIRMRQLIDIVDQLKNYVND LVPEFLPAPEDVETNCEWSAFSCFQ KAQLKSANTGNNERIINVSIKKLKR KPPSTNAGRRQKHRLTCPSCDSYEK KPPKEFLERFKSLLQKMIHQHLSSR THGSEDS |
| Endotoxin : |
< 0.2 EU/μg, determined by LAL method. |
| Purity : |
> 95% by SDS-PAGE analysis. |
| Storage : |
Lyophilized recombinant human Interleukin-21 (rhIL-21) remains stable up to 6 months at -80 centigrade from date of receipt. Upon reconstitution, rhIL-21 should be stable up to 2 weeks at 4 centigrade or up to 3 months at -20 centigrade. |
| Storage Buffer : |
Lyophilized after extensive dialysis against PBS. |
| Reconstitution : |
Reconstituted in ddH2O at 100 μg/mL. |
