IL-21 Protein

Description:
|Introduction IL-21 is produced by CD4+ T cells in response to antigenic stimulation. Its action 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 na?ve 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 (?) 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. |Reco|E. coli-derived. A single, non-glycosylated polypeptide chain containing 133 amino acids and having a total molecular mass of 15,463 Dalton. N-terminal sequence analysis: Gln-Gly-Gln-Asp-Arg. The ED50=1-10 ug/ml corresponding to a Specific Activity of 0.1-1 MIU/mg , determined by the dose-dependant proliferation of human peripheral blood mononuclear cells. Purity > 95%, by SDS-|Lyophilized from a concentrated (1 ug/ml) solution containing no additives. Reconstitution: It is recommended to reconstitute the lyophilized Interleukin-21 in sterile 18 M?-cm H2O not less than 100 ug/ml, which can then be further diluted to other aqueous solutions. Shipping: The product is shipped at a|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. |Other IL-21 Proteins: Recombinant Rat IL-21 Recombinant Mouse IL-21