Species : |
Human |
Source : |
CHO |
Tag : |
Avi&Fc |
Protein Length : |
Val35-Asn242 |
Description : |
B7-1/CD80 and B7-2/CD86, together with their receptors CD28 and CTLA-4, constitute one of the dominant co-stimulatory pathways that regulate T- and B-cell responses (1). Although both CTLA-4 and CD28 can bind to the same ligands, CTLA-4 binds to B7-1 and B7-2 with a 20-100 fold higher affinity than CD28 and is involved in the down-regulation of the immune response (2-6). Mature human B7-1 consists of a 208 amino acid (aa) extracellular domain (ECD) with two immunoglobulin-like domains, a 21 aa transmembrane domain, and a 25 aa cytoplasmic domain (7). Within the ECD, human B7-1 shares 50% aa sequence identity with mouse B7-1. Alternative splicing generates a 30-kDa soluble isoform that lacks the transmembrane segment and retains the ability to bind CD28 and CTLA-4 and an isoform that lacks the second Ig-like domain and the transmembrane segment (8). Both human and mouse B7-1 and B7-2 can bind to either human or mouse CD28 and CTLA-4 (1). B7-1 is expressed on activated B cells, activated T cells, and macrophages. B7-2 is constitutively expressed on interdigitating dendritic cells, Langerhans cells, peripheral blood dendritic cells, memory B cells, and germinal center B cells (2). |
Predicted N Terminal : |
Val35 |
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 CTLA-4 Fc Chimera is immobilized at 0.25 μg/mL (100 μL/well), the concentration of Biotinylated Recombinant Human CD80 Fc/Avi-tag that produces 50% of the optimal binding response is 0.4-2.4 ng/mL. |
Molecular Mass : |
77-89 kDa, under reducing conditions |
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. |