Recombinant Human B7-1 / CD80 Protein, Fc Tag (HPLC-verified), 100µg

Background
B7­1 and B7­2, together with their receptors CD28 and CTLA­4, constitute one of the dominant co-stimulatory pathways that regulate T­ and B­cell responses. Although both CTLA­4 and CD28 can bind to the same ligands, CTLA­4 binds to B7­1 and B7­2 with a 20 ­ 100 fold higher affinity than CD28 and is involved in the down­regulation of the immune response. B-lymphocyte activation antigen B7-1 (referred to as B7) also known as cluster of Differentiation 80 (CD80), is a member of cell surface immunoglobulin superfamily and is expressed on activated B cells, activated T cells, macrophages and dendritic cells. It is the ligand for two different proteins on the T cell surface: CD28 (for autoregulation and intercellular association) and CTLA-4 (for attenuation of regulation and cellular disassociation). CD80 works in tandem with CD86 to prime T cells. CD80 plays a role in induction of innate immune responses by activating NF-κB-signaling pathway in macrophages. CD80 is thus regarded as promising therapeutic targets for autoimmune diseases and various carcinomas.

Source
Recombinant Human B7-1, Fc Tag (HPLC-verified) (B71-H5259) is expressed from human 293 cells (HEK293). It contains AA Val 35 - Asn 242 (Accession # NP_005182.1).
Predicted N-terminus: Val 35

Molecular Characterization
This protein carries a human IgG1 Fc tag at the C-terminus.
The protein has a calculated MW of 50.0 kDa. The protein migrates as 65-90 kDa under reducing (R) condition (SDS-PAGE) due to glycosylation.

Endotoxin
Less than 1.0 EU per μg of the Human B7-1, Fc Tag (HPLC-verified) by the LAL method.

Purity
>95% as determined by SDS-PAGE.
>95% as determined by SEC-HPLC.

Formulation
Lyophilized from 0.22 μm filtered solution in 50 mM tris, 100 mM glycine, pH7.5. Normally Mannitol or Trehalose are added as protectants before lyophilization.
Contact us for customized product form or formulation.

Reconstitution
See Certificate of Analysis for details of reconstitution instruction and specific concentration.

Storage
Avoid repeated freeze-thaw cycles.
No activity loss was observed after storage at:
In lyophilized state for 1 year (4°C-8°C); After reconstitution under sterile conditions for 1 month (4°C-8°C) or 3 months (-20°C to -70°C).

Bioactivity
Please refer to product data sheet

References

(1) Peach RJ., et al., 1995, J. Biol. Chem. (UNITED STATES) 270 (36): 21181–7.
(2) Stamper CC., et al., 2001, Nature (England) 410 (6828): 608–11.
(3) Bhatia S., et al., 2005, Proc. Natl. Acad. Sci. 102: 15569-15574.
(4) Khan N., et al., 2007, Int. Immunol. 19:477-486.