Introduction
Interleukin-5 (IL-5) is a cytokine crucial for the growth and differentiation of B cells and eosinophils. It plays a significant role in eosinopoiesis, regulating eosinophil maturation and activation. Elevated IL-5 levels are implicated in conditions like asthma and hypereosinophilic syndromes. The IL-5 receptor is a heterodimer, sharing its beta subunit with the receptors for IL-3 and GM-CSF. The genes for IL-5, IL-4, IL-13, and CSF2 form a cluster on chromosome 5, regulated by long-range elements spanning 120 kilobases on chromosome 5q31.
Description
Recombinant Human Interleukin-5, produced in E. coli, is a non-glycosylated polypeptide comprising two identical chains, each containing 113 amino acids. This dimeric protein has a molecular mass of 26.5 kDa. The purification process involves proprietary chromatographic techniques.
Physical Appearance
White, sterile-filtered powder obtained through lyophilization (freeze-drying).
Formulation
The product is lyophilized from a 1 mg/ml aqueous solution without any additives.
Solubility
Reconstitute the lyophilized Interleukin-5 in sterile 18 MΩ-cm H2O to a concentration of at least 100 µg/ml. Further dilutions can be made in other aqueous solutions.
Stability
Lyophilized Interleukin-5 remains stable at room temperature for up to 3 weeks. However, for long-term storage, it should be kept desiccated at a temperature below -18°C. After reconstitution, store IL-5 at 4°C for a maximum of 7 days. For extended storage, store below -18°C. Avoid repeated freeze-thaw cycles.
Purity
Exceeds 98.0% purity, as determined by: (a) Reverse-Phase High-Performance Liquid Chromatography (RP-HPLC) analysis and (b) Sodium Dodecyl Sulfate-Polyacrylamide Gel Electrophoresis (SDS-PAGE) analysis.
Biological Activity
The ED50, determined by the dose-dependent stimulation of TF-1 cell proliferation, is less than 0.15 ng/ml. This corresponds to a specific activity greater than 6 x 106 IU/mg.
Synonyms
EDF, BCDFII, TRF, T-cell replacing factor, Eosinophil differentiation factor, B cell differentiation factor I, IL-5.
Amino Acid Sequence
The sequence of the first five N-terminal amino acids was determined and was found to be Met-Ile-Pro-Thr-Glu.
