| Description : |
CD200, also known as OX-2, is a 45 kDa transmembrane immunoregulatory protein that belongs to the immunoglobulin superfamily (1, 2). The human CD200 cDNA encodes a 278 amino acid (aa) precursor that includes a 30 aa signal sequence, a 202 aa extracellular domain (ECD), a 27 aa transmembrane segment, and a 19 aa cytoplasmic domain. The ECD is composed of one Ig-like V-type domain and one Ig-like C2-type domain (3). A splice variant of CD200 has been described and has a truncated cytoplasmic tail. Within the ECD, human CD200 shares 76% aa sequence identity with mouse and rat CD200. CD200 is widely but not ubiquitously expressed (4). Its receptor (CD200R) is restricted primarily to mast cells, basophils, macrophages, and dendritic cells, which suggests myeloid cell regulation as the major function of CD200 (5-7). CD200 knockout mice are characterized by increased macrophage number and activation and are predisposed to autoimmune disorders (8). CD200 and CD200R associate via their respective N-terminal Ig-like domains (9). In myeloid cells, CD200R initiates inhibitory signals following receptor-ligand contact (6, 7, 10). In T cells, however, CD200 functions as a costimulatory molecule independent of the CD28 pathway (11). Several additional CD200R-like molecules have been identified in human and mouse, but their capacity to interact with CD200 is controversial (12, 13). Several viruses encode CD200 homologs which are expressed on infected cells during the lytic phase (14, 15). Like CD200 itself, viral CD200 homologs also suppress myeloid cell activity, enabling increased viral propagation (5, 14-16). |
| Source : |
HEK293 cells |
| Species : |
Human |
| Tag : |
Fc/Avi |
| Predicted N Terminal : |
No results obtained: Gln31 inferred from enzymatic pyroglutamate treatment revealing Val32 |
| Form : |
Lyophilized from a 0.2 μm filtered solution in PBS with Trehalose. |
| Bio-activity : |
Measured by its binding ability in a functional ELISA. When Recombinant Human CD200R1 Fc Chimera is immobilized at 2 μg/mL (100 μL/well), the concentration of Recombinant Human CD200 Fc Chimera Avi-tag that produces 50% of the optimal binding response is 2-10 ng/mL. |
| Molecular Mass : |
60-80 kDa, under reducing conditions |
| Protein length : |
Gln31-Gly232 |
| Endotoxin : |
<0.10 EU per 1 μg of the protein by the LAL method. |
| Purity : |
>95%, by SDS-PAGE visualized with Silver Staining and quantitative densitometry by Coomassie® Blue Staining. |
| Applications : |
Bioactivity |
| Storage : |
Use a manual defrost freezer and avoid repeated freeze-thaw cycles.12 months from date of receipt, -20 to -70 °C as supplied.1 month, 2 to 8 °C under sterile conditions after reconstitution.3 months, -20 to -70 °C under sterile conditions after reconstitution. |
| Reconstitution : |
Reconstitute at 500 μg/mL in PBS. |
