| Source: |
Escherichia coli. |
| Molecular Weight: |
Approximately 15.0 kDa, a single non-glycosylated polypeptide chain containing 129 amino acids. |
| AA Sequence: |
HKCDITLQEI IKTLNSLTEQ KTLCTELTVT DIFAASKNTT EKETFCRAAT VLRQFYSHHE KDTRCLGATA QQFHRHKQLI RFLKRLDRNL WGLAGLNSCP VKEANQSTLE NFLERLKTIM REKYSKCSS |
| Purity: |
> 98% by SDS-PAGE and HPLC analyses. |
| Biological Activity: |
Fully biologically active when compared to standard. The ED50 as determined by a cell proliferation assay using human TF-1 cells is less than 0.2 ng/mL, corresponding to a specific activity of > 5.0 × 106 IU/mg. |
| Physical Appearance: |
Sterile filtered white lyophilized (freeze-dried) powder. |
| Formulation: |
Lyophilized from a 0.2 µm filtered concentrated solution in PBS, pH7.4. |
| Endotoxin: |
Less than 1.0 EU/µg of rHuIL-4 as determined by LAL method. |
| Reconstitution: |
Centrifuge the vial briefly before opening to ensure that the contents settle at the bottom. Reconstitute the vial with sterile distilled water or an aqueous buffer containing 0.1% BSA to achieve a concentration of 0.1-1.0 mg/mL. Divide the resulting stock solution into working aliquots and store them at or below -20°C. For further dilutions, use appropriate buffered solutions. |
| 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. |
| Synonyms: |
BSF-1, Binetrakin, Lymphocyte stimulatory factor 1, Pitrakinra. |
| Background: |
Interleukin-4 (IL-4) is a multifaceted cytokine primarily responsible for the transformation of naive helper T cells (Th0 cells) into Th2 cells. It is chiefly produced by activated T cells, mast cells, and bone marrow stromal cells. IL-4 plays multiple biological roles, such as stimulating the proliferation of activated B and T cells, guiding the differentiation of CD4+ T-cells into Th2 cells, and boosting both the cell surface expression and secretion of IgE and IgG1. Moreover, IL-4 has a role in managing the expression of the low affinity Fc receptor for IgE (CD23) on lymphocytes and monocytes. The mouse IL-4 is a compact, stable globular fold composed of 121 amino acid residues, featuring a single non-glycosylated polypeptide, and is stabilized by three disulphide bonds. The human IL-4 shares around 40% aa sequence identity with mouse/rat IL-4 but is species-specific in its functionality. |
