R&D Systems Recombinant Human IL-2

Interleukin-2 (IL-2) is a O-glycosylated, four α-helix bundle cytokine that has potent stimulatory activity for antigen-activated T cells. It is expressed by CD4+ and CD8+ T cells, γδ T cells, B cells, dendritic cells, and eosinophils.

Specifications and Use of R&D IL-2
 
Source
• A DNA sequence encoding the mature human IL-2 protein sequence (Taniguchi et al., 1983, Nature 302: 305 - 310; Maeda et al., 1983, Biochem. Biophys. Res. Commun. 115: 1040 - 1047) was expressed in E. coli.

Molecular Mass of R&D IL-2
• The methionyl form of the E. coli expressed mature human IL-2 contains 134 amino acid residues and has a predicted molecular mass of approximately 15 kDa.

Purity of R&D IL-2
• > 97%, as determined by SDS-PAGE and visualized by silver stain.

Endotoxin Level
• < 1.0 EU per 1 μg of the cytokine as determined by the LAL method.

Activity of R&D IL-2
• Measured in a cell proliferation assay using an IL-2 dependent murine cytotoxic T cell line, CTLL-2 (Gearing, A.J.H. and C.B. Bird in Lymphokines and Interferons, a Practical Approach. 1987, M.J. Clemens, A.G. Morris and A.J.H. Gearing, eds., IRL Press, p. 296).
• The ED50 for this effect is typically 0.25 - 0.5 ng/mL.

Formulation
• Lyophilized from a 0.2 μm filtered solution in 50 mM sodium acetate (pH 4.0) containing 50 μg of bovine serum albumin per 1 μg of cytokine.

Reconstitution of R&D IL-2
• It is recommended that sterile PBS containing at least 0.1% human serum albumin or bovine serum albumin be added to the vial to prepare a stock solution of no less than 10 μg/mL of the cytokine.

Storage of R&D IL-2
• Lyophilized samples are stable for up to twelve months at -20° C to -70° C.
• Upon reconstitution, this cytokine can be stored under sterile conditions at 2° - 8° C for one month or at -20° C to -70° C in a manual defrost freezer for three months without detectable loss of activity.
• Avoid repeated freeze-thaw cycles.