4-1BB Receptor (CD137) is a member of the TNF receptor superfamily expressed on activated CD4 and CD8 T cells as well as on activated natural killer cells. The binding of 4-1BB to its TNF family ligand, 4-1BB ligand (4-1BBL) delivers a costimulatory signal to resting T cells leading to high level IL-2 production independently of CD28 signaling.
The activity was tested by the ability of immobilized recombinant mouse 4-1BBL to bind human 4-1BB with a linear range of 10-500 ng/mL.
Recombinant Human CD137 is lyophilized from 0.2 ?m filtered PBS solution, pH7.2.
A quick spin of the vial followed by reconstitution in distilled water to a concentration not less than 0.1 mg/mL. This solution can then be diluted into other buffers.
>95% as determined by SDS-PAGE
<1.0 EU/μg of recombinant protein as determined by the LAL method.
Recombinant Human CD137 can be stored in working aliquots at 2? - 8?C for one month, or at -20?C to -70?C for twelve months.
Avoid repeated freeze/thaw cycles.