NTB-A (NK-T-B-antigen), also known as Ly108 and SLAMF6, is a 60kD type I transmembrane glycoprotein that belongs to the SLAM subgroup of the CD2 family (1). Mature human NTB-A contains a 205 amino acid (aa) extracellular domain (ECD) with one Ig-like V-set and one Ig-like C2-set domain. It also contains a 21 aa transmembrane segment and an 84 aa cytoplasmic domain with two immunoreceptor tyrosine-based switch motifs (ITSMs) (2, 3). An alternately spliced isoform is truncated in the cytoplasmic domain and lacks the two ITSMs. Within the ECD, human NTB-A shares 48% aa sequence identity with mouse and rat NTB-A. The ECD of human NTB-A shares 19%-34% aa sequence identity with comparable regions of human 2B4, BLAME, CD2F-10, CD84, CD229, CRACC, and SLAM. NTB-A is expressed on the surface of NK, T, and B lymphocytes as well as eosinophils (2, 4, 5). It interacts homophilically through weak associations between the Ig-V domains (2, 5-7). NTB-A functions as an activating coreceptor on NK and T cells (2, 5, 6, 8). Tyrosine phosphorylation in the membrane proximal ITSM enables specific association with EAT-2, an interaction that is required for NTB-A mediated cytotoxicity of NK cells (9). Phosphorylation-dependent NTB-A association with SAP is required for full production of IFN-γ by NK cells (5, 9). This interaction is independent of EAT-2 binding and appears to involve the membrane distal ITSM (5, 9). NTB-A deficient mice show weakened Th2 responses and elevated levels of neutrophil-derived inflammatory mediators (10). On B cells, NTB-A modulates immunoglobulin class switching and the balance between tolerance and autoimmunity (5, 11).
Source: DNA sequence encoding the extracellular domain of human NTB-A (Leu 28-Lys 225; Accession # Q96DU3) was fused to the Fc region of human IgG1 via a peptide linker. The chimeric protein was expressed in a mouse myeloma cell line, NS0.
Definition: Measured by its ability to bind biotinylated rhNTB-A in a functional ELISA type binding assay.
Applications:Suitable for use inWestern Blot. Other applications not tested.
Recommended Dilution:Western Blot: 48.9kD migrates as an ~ 65-80kD protein in SDS-PAGE under reducing conditions. Optimal dilutions to be determined by the researcher.
Storage and Stability:Lyophilized powder may be stored at 4°C for short-term only. Reconstitute to nominal volume by adding sterile PBS and store at -20°C. Reconstituted product is stable for 12 months at -20°C. For maximum recovery of product, centrifuge the original vial after thawing and prior to removing the cap. Further dilutions can be made in assay buffer.
仕様
Size：50ug
Source Antigen：Recombinant Human
Grade：Highly Purified
Purity：≥ 90%, as determined by SDS-PAGE and visualized by silver stain. Endotoxin ≤ 1EU.
Form：Supplied as a lyophilized powder in PBS. Reconstitute with sterile PBS to ≥ 0.1mg/ml.
