Recombinant Human/Cynomolgus/Rhesus macaque CD28(hFc Tag)

Description :
FAQ COA 已发表文献 CD28 and CTLA-4, together with their ligands, B7-1 and B7-2, constitute one of the dominant co-stimulatory pathways that regulate Tand Bcell responses. CD28 and CTLA-4 are structurally homologous molecules that are members of the Ig gene superfamily. Both CD28 and CTLA-4 are composed of a single IgV-like extracellular domain, a transmembrane domain and an intracellular domain. CD28 and CTLA-4 are both expressed on the cell surface as disulfide-linked homodimers or as monomers. The genes encoding these two molecules are closely linked on human chromosome2 and mouse chromosome1. Mouse CD28 is expressed constitutively on virtually 100%of mouse Tcells and on developing thymocytes. Cell surface expression of mouse CD28 is down-regulated upon ligation of CD28 in the presence of PMA or PHA. In contrast, CTLA-4 is not expressed constitutively but is up-regulated rapidly following Tcell activation and CD28ligation. Cell surface expression of mouse CTLA-4 peaks approximately 48hours after activation. Although both CTLA-4 and CD28 can bind to the same ligands, CTLA-4 binds to B7-1 and B7-2 with a 20-100fold higher affinity than CD28. CD28/B7 interaction has been shown to prevent apoptosis of activated Tcells via theup-regulation of bcl-XL. 产品性质 别名Synonyms CD28 antigen (Tp44); CD28 molecule; CD28; MGC138290 Uniprot No. P10747-1 Source Recombinant Human/Cynomolgus/Rhesus macaque CD28 is expressed from HEK293 Cellswith hFc tag at the N-terminal. It contains Asn19-Pro152. 分子量(Molecular Weight) The protein has a predicted MW of 42.6 kDa. Due to glycosylation, the protein migrates to 55-70 kDa based on Tris-Bis PAGE result. 外观(Physical Appearance Sterile Filtered White lyophilized (freeze-dried) powder. Purity > 95% as determined by SDS-PAGEand HPLC Activity ELISA DataImmobilized Human/Cynomolgus/Rhesus macaque CD28, hFc Tag at 0.2g/ml (100l/Well) on the plate. Dose response curve for Biotinylated Anti-CD28 Antibody, hFc Tag with the EC50of 33.9ng/ml determined by ELISA. 内毒素Endotoxin 1.0EU per 1g of the protein by the LAL method. Formulation Lyophilized from 0.22m filtered solution in PBS (pH 7.4). Normally 5% trehalose is added as protectant before lyophilization. 复溶Reconstitution Centrifuge tubes before opening. Reconstituting to a concentration more than 100 g/mLis recommended (usually we use 1mg/mLsolution for lyophilization). Dissolve the lyophilized protein in distilled water.