ED 50 < 1.0 ng/ml, measured by its ability to stimulate the proliferation of human ANBL-6 cells, corresponding to a specific activity of > 1.0 × 10^6 units/mg.

IL-21 Protein, Mouse, Recombinant V2 is expressed in E. coli. The accession number is Q9ES17-1.

Mouse

E. coli

Pro25-Ser146 Expressed with an N-terminal Met

> 98% as determined by SDS-PAGE

Lyophilized powders can be stably stored for over 12 months, while liquid products can be stored for 6-12 months at -80°C. For reconstituted protein solutions, the solution can be stored at -20°C to -80°C for at least 3 months. Please avoid multiple freeze-thaw cycles and store products in aliquots.

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. The IL-21 receptor is highly expressed on CD4 + and CD8 + B cells. IL-21 plays a pivotal role in the survival and proliferation of B cells, and their differentiation to immunoglobulin (Ig) producing cells. IL-21regulates the production of IgG1 and IgE by B cells, and diminishes the severity of allergy and asthma. In some cases, IL-21 induces B cell apoptosis. Other roles of IL-21 include regulation of the innate immune system, implication in autoimmunity, and antitumor activity.