Biological activity was determined by the dose - dependent stimulation of IL - 8 production by human PBMC. The ED50 for this effect is 5 - 10 ng/mL. Please Note: Results may vary with PBMC donors.
Properties
PURITY:
Greater than 98% by SDS-PAGE gel and HPLC analyses.
Endotoxin level is less than 0.1 ng per μg (1EU/μg).
PHYSICAL STATE:
Lyophilized
STORAGE CONDITIONS:
The lyophilized 4-1BB Ligand recombinant protein is stable for at least 2 years from date of receipt at -20˚C. Reconstituted 4-1BB Ligand is stable for at least 3 months when stored in working aliquots with a carrier protein at -20˚C. As with any protein, exposing 4-1BB Ligand recombinant protein to repeated freeze / thaw cycles is not recommended. When working with proteins care should be taken to keep recombinant protein at a cool and stable temperature.
4-1BBL, a member of the TNF superfamily, is expressed in B cells, dendritic cells, activated T cells and macrophages. 4-1BBL binds to its receptor 4-1BB, and provides a co-stimulatory signal for T cell activation and expansion. The human 4-1BBL gene codes for a 254 amino acid type II transmembrane containing a 28 amino acid cytoplasmic domain, a 21 amino acid transmembrane domain, and a 205 amino acid extracellular domain. The soluble form of 4-1BBL contains the TNF-like portion of the extracellular domain of 4-1BBL. Recombinant human 4-1BBL is a soluble 19.5 kDa protein consisting of 185 amino acid residues.