E. coli-derived human IL-2 protein Ala21-Thr153 (Cys145Ser), with and without an N-terminal Met
>97%, by SDS-PAGE visualized with Silver Staining and quantitative densitometry by Coomassie® Blue Staining.
<0.01 EU per 1 μg of the protein by the LAL method.
N-terminal sequence Analysis
Ala21 & Met
Predicted Molecular Mass
13 kDa, under reducing conditions.
Measured in a cell proliferation assay using CTLL‑2 mouse cytotoxic T cells. Gearing, A.J.H. and C.B. Bird (1987) in Lymphokines and Interferons, A Practical Approach. Clemens, M.J. et al. (eds): IRL Press. 295. The ED50 for this effect is 0.0300-0.250 ng/mL.
Recombinant Human IL-2 Protein, CF Scientific Data Examples
Recombinant Human IL‑2 Protein Bioactivity.
Measured in a cell proliferation assay using CTLL‑2 mouse cytotoxic T cells. The ED50 for this effect is 0.0300-0.250 ng/mL.
Equivalent Bioactivity of GMP, Animal-Free, and RUO grades of Recombinant Human IL-2.
Equivalent bioactivity of GMP (BT-002-GMP), Animal-Free (BT-002-AFL) and RUO (Catalog # BT-002) grades of Recombinant Human IL-2 as measured in a cell proliferation assay using CTLL-2 mouse cytotoxic T cells (orange, green, red, respectively).
Recombinant Human IL‑2 Protein SDS-PAGE.
2 μg/lane of Recombinant Human IL‑2 Protein (Catalog # BT-002) was resolved with SDS-PAGE under reducing (R) and non-reducing (NR) conditions and visualized by Coomassie® Blue staining, showing bands at 13 kDa.
Formulation, Preparation and Storage
What does CF mean?
CF stands for Carrier Free (CF). We typically add Bovine Serum Albumin (BSA) as a carrier protein to our
Adding a carrier protein enhances protein stability, increases shelf-life, and allows the recombinant
protein to be stored at a more dilute concentration.
The carrier free version does not contain BSA.
What formulation is right for me?
In general, we advise purchasing the recombinant protein with BSA for use in cell or tissue culture, or
as an ELISA standard.
In contrast, the carrier free protein is recommended for applications, in which the presence of BSA
Lyophilized from a 0.2 μm filtered solution in Sodium Acetate with Trehalose.
Reconstitute the 10 μg size at 100 μg/mL in sterile deionized water. Reconstitute all other sizes at 500 μg/mL in sterile deionized water.
The product is shipped at ambient temperature. Upon receipt, store it immediately at the temperature recommended below.
Stability & Storage:
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.
Recombinant Interleukin-2 (IL-2) is expressed in E. coli and has been engineered to contain the serine for cysteine substitution found in Proleukin® (aldesleukin). Recombinant IL-2 is widely used in cell culture for the expansion of T cells.
IL-2 is expressed by CD4+ and CD8+ T cells, gamma δ T cells, B cells, dendritic cells, and eosinophils (1 - 3). Mature human IL-2 shares 56% and 66% amino acid (aa) sequence identity with mouse and rat IL-2, respectively. Human and mouse IL-2 exhibit cross-species activity (4). The receptor for IL-2 consists of three subunits that are present on the cell surface in varying preformed complexes (5 - 7). The 55 kDa IL-2 R alpha is specific for IL-2 and binds with low affinity. The 75 kDa IL-2 R beta, which is also a component of the IL-15 receptor, binds IL-2 with intermediate affinity. The 64 kDa common gamma chain gamma c/IL-2 R gamma, which is shared with the receptors for IL-4, -7, -9, -15, and -21, does not independently interact with IL-2. Upon ligand binding, signal transduction is performed by both IL-2 R beta and gamma c. IL-2 is best known for its autocrine and paracrine activity on T cells. It drives resting T cells to proliferate and induces IL-2 and IL-2 R alpha synthesis (1, 2). It contributes to T cell homeostasis by promoting the Fas-induced death of naïve CD4+ T cells but not activated CD4+ memory lymphocytes (8). IL-2 plays a central role in the expansion and maintenance of regulatory T cells, although it inhibits the development of Th17 polarized cells (9 - 11). Thus, IL-2 may be a key cytokine in the natural suppression of autoimmunity (12, 13).
Ma, A. et al. (2006) Annu. Rev. Immunol. 24:657.
Gaffen, S.L. and K.D. Liu (2004) Cytokine 28:109.
Taniguchi, T. et al. (1983) Nature 302:305.
Mosmann, T.R. et al. (1987) J. Immunol. 138:1813.
Liparoto, S.F. et al. (2002) Biochemistry 41:2543.
Wang, X. et al. (2005) Science 310:1159.
Bodnar, A. et al. (2008) Immunol. Lett. 116:117.
Jaleco, S. et al. (2003) J. Immunol. 171:61.
Malek, T.R. (2003) J. Leukoc. Biol. 74:961.
Laurence, A. et al. (2007) Immunity 26:371.
Kryczek, I. et al. (2007) J. Immunol. 178:6730.
Afzali, B. et al. (2007) Clin. Exp. Immunol. 148:32.
Fehervari, Z. et al. (2006) Trends Immunol. 27:109.
Which Brands are Currently Available on bio‑techne.com? R&D Systems, Tocris Bioscience and ProteinSimple branded products are available to purchase through bio‑techne.com. ProteinSimple branded instruments are available to quote. ACD branded products will be available on bio‑techne.com in the near future. Novus Biologicals branded products are not currently available on bio‑techne.com and can be found at novusbio.com.
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