Recombinant Human CD40 /TNFRSF5 Protein, His Tag, 200µg

Background
Tumor necrosis factor receptor superfamily member 5 (TNFRSF5) also known as CD40, is a member of the TNF receptor superfamily. The expression of CD40 is diverse. TNFRSF5 has been found to be essential in mediating a broad variety of immune and inflammatory responses including T cell-dependent immunoglobulin class switching, memory B cell development, and germinal center formation. CD40 is the receptor for TNFSF5/CD40LG. Defects in CD40 are the cause of immunodeficiency with hyper-IgM type 3 (HIGM3).

Source
Recombinant Human CD40, His Tag (CD0-H5228) is expressed from human 293 cells (HEK293). It contains AA Glu 21 - Arg 193 (Accession # P25942-1).
Predicted N-terminus: Glu 21

Molecular Characterization
This protein carries a polyhistidine tag at the C-terminus.
The protein has a calculated MW of 21.1 kDa. The protein migrates as 29-32 kDa under reducing (R) condition (SDS-PAGE) due to glycosylation.

Endotoxin
Less than 1.0 EU per μg by the LAL method.

Purity
>95% as determined by SDS-PAGE.

Formulation
Lyophilized from 0.22 μm filtered solution in PBS, pH7.4. Normally trehalose is added as protectant before lyophilization.

Reconstitution
Please see Certificate of Analysis for specific instructions.
For best performance, we strongly recommend you to follow the reconstitution protocol provided in the CoA.

Storage
For long term storage, the product should be stored at lyophilized state at -20°C or lower.
Please avoid repeated freeze-thaw cycles.
No activity loss is observed after storage at:
4-8°C for 12 months in lyophilized state;
-70°C for 3 months under sterile conditions after reconstitution.
 
Bioactivity
Human CD40, His Tag (Cat. No. CD0-H5228) ELISA bioactivity
Immobilized Human CD40, His Tag (Cat. No. CD0-H5228) at 1 μg/mL (100 μL/well) can bind Human CD40 Ligand, Fc Tag with a linear range of 1-16 ng/mL (QC tested).

References

(1) Ferrari S., et al., 2001, Proc. Natl. Acad. Sci. U.S.A. 98:12614-12619,
(2) Singh J., et al., 1998, Protein Sci. 7:1124-1135.