Recombinant Biotinylated Human PD-L1 / B7-H1, His Tag & Fc Tag, Avi Tag (Avitag™), 25µg

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 Biotinylated Human PD-L1, Fc,Avitag,His Tag (PD1-H82F3) 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 fragment at the C-terminus, followed by a polyhistidine tag. The Avi tag (Avitag™) is inserted in-between the Fc and his tags. The protein has a calculated MW of 53.2 kDa. The protein migrates as 66-75 kDa on a SDS-PAGE gel under reducing (R) condition due to glycosylation.

Biotinylation
Biotinylation of this product is performed using Avitag™ technology. Briefly, the single lysine residue in the Avitag is enzymatically labeled with biotin.

Biotin:Protein Ratio
The biotin to protein ratio is 0.5-1 as determined by the HABA assay.

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 Tris with Glycine, Arginine and NaCl, pH7.5. Normally trehalose is added as protectant before lyophilization.

Reconstitution
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
Please refer to product data sheet.

Limited Use License
The Biotin AviTag technology is covered by U.S. Pat. No: 5,874,239 and includes any and all materials, methods, kits and related derivatives claimed by this patent. The purchase of the Acrosbiosystems’s Avitag™ proteins confers to the purchaser the limited right to use the Avitag™ technology for non-commercial, or research use, or for purposes of evaluating the Avitag™ technology.
Commercial use of the Avitag™ technology to manufacture a commercial product, or use of the Avitag™ technology to facilitate or advance research which will be applied to the development of a commercial product requires a license from Avidity, LLC. Examples of Commercial use include, but are not limited to biosensors, diagnostics, therapeutic applications, proximity assays, and drug screening assays.

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.