Description:
Interleukin 15 is a cytokine that shares many biological properties with IL-2, including T, B and NK cell-stimulatory activities. Human IL-15 shares approximately 97% and 73% sequence identity with simian and murine IL-15, respectively. Both human and simian IL-15 are active on murine cells. Human IL-15 cDNA encodes a 162 amino acid residue precursor protein containing a 48 amino acid residue signal peptide that is cleaved to yield the 114 amino acid residue mature protein. The IL-15 mRNA is expressed by a wide variety of cells and tissues and is most abundantly expressed by adherent peripheral blood mononuclear cells, fibroblasts and epithelial cells. However, in activated peripheral blood T lymphocytes where IL-2 is highly expressed, the expression of IL-15 is not detectable. Although IL-15 lacks sequence homology with IL-2, it has recently been shown that both the beta and gamma chains of the IL-2 receptor are utilized for IL-15 binding and signaling.
Molecular Weight:
Monomer, 12.9 kDa (115aa)
Physical State:
Lyophilized
Formulation:
Sterile filtered solution containing 10 mM sodium bicarbonate, pH 8.5
Purity:
≥ 95% by reducing and non-reducing SDS-PAGE
Biological Activity:
ED50 ≤ 5 ng/ml, determined by a proliferation assay using murine CTLL-2 cells. ED50 ≤ 2 pg/ml, determined by a proliferation assay using MO7e cells.
Specific Activity:
≥ 2.0 x 10^5 units/mg by CTLL-2 cell proliferation. ~2.7 x 10^5 IU/μg, which is calibrated against recombinant human IL-15 WHO International Standard (NIBSC code: 91/678) in MO7e cells
Endotoxin Level:
Less than 1EU/μg as determined by LAL method
Amino Acid Sequence:
MNWVNVISDL KKIEDLIQSM HIDATLYTES DVHPSCKVTA MKCFLLELQV ISLESGDASI HDTVENLIIL ANNSLSSNGN VTESGCKECE ELEEKNIKEF LQSFVHIVQM FINTS
Reconstitution:
Centrifuge vial prior to opening. Add sterile distilled water or aqueous buffer to a concentration of 0.1-1.0 mg/ml. Further dilutions should be made in appropriate buffered solutions.
Storage/Stability:
Store at -20 °C to -80 °C for up to 1 year.
