Human IL-2, Tag Free (IL2-H4113) is expressed from E.coli cells. It contains AA Ala 21 - Thr 153 (Accession # P60568).
Predicted N-terminus: Ala 21
This protein carries no "tag".
The protein has a calculated MW of 15.4 kDa. The protein migrates as 17 kDa under reducing (R) condition (SDS-PAGE).
Less than 1.0 EU per μg by the LAL method.
>95% as determined by SDS-PAGE.
Lyophilized from 0.22 μm filtered solution in PBS, pH5.0. Normally trehalose is added as protectant before lyophilization.
Contact us for customized product form or formulation.
Please see Certificate of Analysis for specific instructions.
For best performance, we strongly recommend you to follow the reconstitution protocol provided in the CoA.
For long term storage, the product should be stored at lyophilized state at -20°C or lower.
Please avoid repeated freeze-thaw cycles.
No activity loss was observed after storage at:
- 4-8°C for 12 months in lyophilized state;
- -70°C for 3 months under sterile conditions after reconstitution.
Human IL-2, Tag Free on SDS-PAGE under reducing (R) condition. The gel was stained overnight with Coomassie Blue. The purity of the protein is greater than 95%.
Immobilized Human IL-2 R alpha, Fc Tag (Cat. No. ILA-H5251) at 2μg/mL (100 μL/well) can bind Human IL-2, Tag Free (Cat. No. IL2-H4113) with a linear range of 0.2-1.56 ng/mL (QC tested).
Human IL-2 R beta, Fc Tag (Cat. No. ILB-H5253) captured on CM5 chip via anti-human IgG Fc antibody, can bind IL-2, Tag Free (Cat. No. IL2-H4113) with an affinity constant of 0.6 μM as determined in a SPR assay (Biacore T200) (Routinely tested).
活性（Bioactivity）-Cell based assay
Human IL-2, Tag Free (Cat. No. IL2-H4113) stimulates proliferation of CTLL-2 cells. The ED50 for this effect is 0.284-0.355 ng/ml (Routinely tested).
Interleukin-2 (IL-2) is an interleukin, a type of cytokine immune system signaling molecule, which is a leukocytotrophic hormone that is instrumental in the body's natural response to microbial infection and in discriminating between foreign (non-self) and self. IL-2 mediates its effects by binding to IL-2 receptors, which are expressed by lymphocytes, the cells that are responsible for immunity. Mature human IL-2 shares 56% and 66% aa sequence identity with mouse and rat IL-2, respectively. Human and mouse IL-2 exhibit crossspecies activity. The receptor for IL-2 consists of three subunits that are present on the cell surface in varying preformed complexes. IL-2 is also necessary during T cell development in the thymus for the maturation of a unique subset of T cells that are termed regulatory T cells (T-regs). After exiting from the thymus, T-Regs function to prevent other T cells from recognizing and reacting against "self antigens", which could result in "autoimmunity". T-Regs do so by preventing the responding cells from producing IL-2. Thus, IL-2 is required to discriminate between self and non-self, another one of the unique characteristics of the immune system.