Recombinant Human PD-L1/B7-H1 Protein,ow endotoxin, Fc Tag, 2x500µg

Background
Programmed cell death 1 ligand 1 (PD-L1) is also known as cluster of differentiation (CD274) or B7 homolog 1 (B7-H1), is a member of the growing B7 family of immune molecules and is involved in the regulation of cellular and humoral immune responses. B7-H1 is a cell surface immunoglobulin superfamily with two Ig-like domains within the extracellular region and a short cytoplasmic domain. PD-L1 is highly expressed in the heart, skeletal muscle, placenta and lung and weakly expressed in the thymus, spleen, kidney and liver. PD-L1 is expressed on activated T-cells, B-cells, dendritic cells, keratinocytes and monocytes. PD-L1 is up-regulated on T- and B-cells, dendritic cells, keratinocytes and monocytes after LPS and IFNG activation and up-regulated in B-cells activated by surface Ig cross-linking. PD-L1 involve in the costimulatory signal, essential for T-cell proliferation and production of IL10 and IFNG, in an IL2-dependent and a PDCD1-independent manner.

Source
Recombinant Human PD-L1, Fc Tag (PD1-H5258) is expressed from human 293 cells (HEK293). It contains AA Phe 19 - Arg 238 (Accession # NP_054862.1).
Predicted N-terminus: Phe 19

Molecular Characterization
This protein carries a human IgG1 Fc tag at the C-terminus.
The protein has a calculated MW of 51.3 kDa. The protein migrates as 60-75 kDa under reducing (R) condition (SDS-PAGE) due to glycosylation.

Endotoxin
Less than 0.1 EU per μg of the rh PD-L1 / B7-H1 Fc Chimera by the LAL method.

Purity
>95% as determined by SDS-PAGE and SEC-HPLC.
>90% as determined by SEC-MALS.

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

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) Dong H., et al., 1999, Nat. Med. 5:1365-1369.
(2) Freeman G.J., et al., 2000, J. Exp. Med. 192:1027-1034.
(3) Nishimura H., et al., 2001, Trends in Immunology 22:265.