分子量:24.7 kDa

纯度:>95% as determined by SDS-PAGE.

内毒素:Less than 1.0 EU per μg of the Human B7-1, His Tag by the LAL method.

Buffer:PBS, pH7.4

生物活性:(1) Measured by its binding ability in a functional ELISA. 
Immobilized Human B7-1, His Tag (Cat# B71-H5228) at 20μg/mL (100 l/well),can bind Human CD28, Fc Tag (Cat# CD8-H5257) with a linear of 0.2-20 μg/mL.
(2) Measured by its ability to induce IL2 secretion by Jurkat human acute T cell leukemia cells.
TheED50 forthiseffectistypically0.01 - 0.1g/mLinthepresenceofPHA.


产品特性:Human B7-1, His Tag is fused with a polyhistidine tag at the C-terminus, and has a calculated MW of 24.7 kDa. The predicted N-terminus is Val 35. The reducing (R) protein migrates as 44-50 kDa in SDS-PAGE  due to different glycosylation.

产品背景:B7-1 and B7-2, together with their receptors CD28 and CTLA4, constitute one of the dominant co-stimulatory pathways that regulate T and Bcell responses. Although both CTLA4 and CD28 can bind to the same ligands, CTLA4 binds to B71 and B72 with a 20  100 fold higher affinity than CD28 and is involved in the downregulation of the immune response.
B-lymphocyte activation antigen B7-1 (referred to as B7) also known as cluster of Differentiation 80 (CD80), is a member of cell surface immunoglobulin superfamily and is expressed on activated B cells, activated T cells, macrophages and dendritic cells. It is the ligand for two different proteins on the T cell surface: CD28 (for autoregulation and intercellular association) and CTLA-4 (for attenuation of regulation and cellular disassociation). CD80 works in tandem with CD86 to prime T cells. CD80 plays a role in induction of innate immune responses by activating NF-κB-signaling pathway in macrophages. CD80 is thus regarded as promising therapeutic targets for autoimmune diseases and various carcinomas.