Recombinant Human CD200 His-tag Avi-tag Protein, CF

Recombinant Human CD200 His-tag Avi-tag Protein, CF Summary

Product Specifications

Product Datasheets

Carrier Free

CF stands for Carrier Free (CF). We typically add Bovine Serum Albumin (BSA) as a carrier protein to our recombinant proteins. Adding a carrier protein enhances protein stability, increases shelf-life, and allows the recombinant protein to be stored at a more dilute concentration. The carrier free version does not contain BSA.

In general, we advise purchasing the recombinant protein with BSA for use in cell or tissue culture, or as an ELISA standard. In contrast, the carrier free protein is recommended for applications, in which the presence of BSA could interfere.

Background: CD200

Cluster of Differentiation-200 (CD200), also known as OX-2, is a transmembrane immunoregulatory protein that belongs to the immunoglobulin superfamily (1, 2). Mature human CD200 consists of an extracellular domain (ECD) with one Ig-like V-type domain and one Ig-like C2-type domain, a transmembrane segment, and a short cytoplasmic domain (3). Within the mature ECD, human CD200 shares 76% amin acid (aa) sequence identity with mouse and rat CD200. A splice variant of CD200 has been identified lacking the first 43 aa of the ECD and characterized as a functional antagonist to full-length CD200 (4). CD200 is widely expressed by numerous cell types including neurons, B cells, activated T cells, thymocytes, dendritic cells and endothelium (5). Its receptor, CD200R, is restricted primarily to mast cells, basophils, macrophages, and dendritic cells, which suggests CD200 is an important inhibitory ligand for myeloid cell regulation (6-8). CD200 knockout mice are characterized by increased macrophage number and activation and are predisposed to autoimmune disorders (9). CD200 and CD200R associate via their respective N-terminal Ig-like domains (10). In myeloid cells, CD200R initiates inhibitory signals following receptor-ligand contact (7, 8, 11). In T cells, however, CD200 functions as a costimulatory molecule independent of the CD28 pathway (12). Several additional CD200R-like molecules have been identified in human and mouse, but their capacity to interact with CD200 is controversial (13, 14). Several viruses encode CD200 homologs which are expressed on infected cells during the lytic phase (15, 16). Like CD200 itself, viral CD200 homologs also suppress myeloid cell activity, enabling increased viral propagation (6, 15-17). Our Avi-tag Biotinylated human CD200 features biotinylation at a single site contained within the Avi-tag, a unique 15 amino acid peptide. Protein orientation will be uniform when bound to streptavidin-coated surface due to the precise control of biotinylation and the rest of the protein is unchanged so there is no interference in the protein's bioactivity.

Related Research Areas

• Co-stimulatory and Co-inhibitory Molecules
• Leukocyte Receptors/Markers in Tfh Cell Differentiation and Function
• Microglia Development
• Microglia Homeostasis
• Skin Stem Cell Markers