Background
Cluster of Differentiation 3 (CD3) is a multimeric protein complex and T cell co-receptor that plays an essential role in adaptive immune responses. This complex is composed of four distinct polypeptide chains: epsilon (ε), gamma (γ), delta (δ), and zeta (ζ), which assemble as three pairs of dimers (εγ, εδ, ζζ). These CD3 molecules bind non-covalently to the T-cell receptor (TCR) to form the TCR/CD3 receptor complex on the surface of T cells.
CD3 proteins interactions with T cells
The CD3 proteins have a transmembrane domain, a cytoplasmic tail, and an N-terminal extracellular region containing immunoglobulin-like domains, classifying them as part of the immunoglobulin superfamily. The intracellular immunoreceptor tyrosine-based activation motifs (ITAMs) located in the cytoplasmic tails are essential for signal transduction upon T cell receptor engagement.
The CD3 complex is a defining feature of the T cell lineage and is involved in activating both cytotoxic T cells (CD8+ naive T cells) and T helper cells (CD4+ naive T cells). Antibodies against CD3 molecules can either stimulate or block T cell activation signal transduction, offering a potential avenue for developing treatments for organ transplant rejection and autoimmune diseases.
Comprehensive Collection of Bioactive CD3 Homodimers, Heterodimers, & Monomers
Through KACTUS’ unique SAMS™ protein engineering and expression platform, KACTUS provides a variety of highly active CD3 proteins, including monomers, dimers, and other forms, to meet the diverse needs of researchers in immunology, antibody preparation, and screening.
Product Applications:
Antibody discovery:
Immunisation
Antibody screening
Functional characterisation
Affinity determination:
ELISA / SPR / BLI
Product Features:
- High protein binding affinity
- Equal expression of subunits in dimers
- Batch-to-batch stability studies
- Temperature stability studies
- Mammalian Expression
- Various tags, species & molecules
- Customisable
Product Validation Data
We verified the activity of our heterodimers, such as CD3E/G-His Tag and CD3E/D-His Tag, via ELISA and SPR.
A proprietary design, expression, and purification system ensures the two subunits of the heterodimers are expressed in equal proportions with greater than 95% purity, verfied by SDS-PAGE and SEC-HPLC.
Our CD3 proteins have high batch-to-batch consistency and long-term stability as verified by ELISA.
Immobilized Human CD3E/CD3G, hFc Tag, at 1ug/mL (100ul/well). Dose-response curve for anti-CD3E/CD3G antibody (OKT3, mFc Tag). The EC50s are 20.7, 19.5, 20.0 and 20.7ng/ml respectively, as determined by ELISA.
Caltag Medsystems is the distributor of KACTUS products in the UK and Ireland. If you have any questions about these products, please contact us.