HHLA2 Protein, Human, Recombinant (ECD, His Tag), Biotinylated

B7H7 gene encodes a protein-ligand found on the surface of monocytes. The encoded protein is thought to regulate cell-mediated immunity by binding to a receptor on T lymphocytes and inhibiting the proliferation of these cells. Alternate splicing results in multiple transcript variants. HERV–H LTR-associating 2 (HHLA2, also called B7H7/B7-H5/B7y) has been recently discovered as the newest member of the B7 family and has 23–33% similarity in amino acid sequence with the other B7 molecules. This ligand is the only B7 family member that is found in humans but not in mice. It is constitutively expressed on the surface of human monocytes and is induced on B cells. HHLA2 binds to its putative receptor (s) on a variety of immune cells including CD4 and CD8 T cells and antigen-presenting cells. Similar to B7-H3, both a T cell coinhibitory role, as well as a costimulatory role, has been reported for this ligand.

At Leading Biology, the biological activity of a recombinant protein is routinely measured using a bioassay, e.g. chemotaxis or cell proliferation assay, enzyme assay, or a functional ELISA. When a recombinant protein is an enzyme, specific activity is derived from an enzymatic assay. Each enzyme is tested for potency by cleavage of a substrate. We are in the process of updating the biological activity data. If you have any questions regarding this update, please feel free to contact our technical support team.

Lyophilized from sterile PBS, pH 7.4. Please contact us for any concerns or special requirements. Normally 5 % - 8 % trehalose, mannitol and 0.01% Tween 80 are added as protectants before lyophilization. Please refer to the specific buffer information in the hard copy of CoA.

The recombinant human HHLA2 consists of 333 amino acids and predicts a molecular mass of 38.4 kDa. As a result of glycosylation, it migrates as an approximately 55 KDa band in SDS-PAGE under reducing conditions.

In general, recombinant proteins are provided as lyophilized powder which are shipped at ambient temperature. Bulk packages of recombinant proteins are provided as frozen liquid. They are shipped out with blue ice unless customers require otherwise. Stable for 1 year at -20°C or below from date of shipment. For maximum recovery of product, centrifuge the original vial after thawing and opening the cap. For long-term storage, aliquot and store at -20°C or below. Avoid repeated freeze-thaw cycles.

A DNA sequence encoding the human HHLA2 (NP_009003.1) (Met1-Asn344) was expressed with a polyhistidine tag at the C-terminus. The purified protein was biotinylated in vitro.