Recombinant T cell receptor alpha variable 21 (TRAV21) fragment (residues 20-112) from Homo sapiens, engineered for structural and functional studies. This 93-amino acid soluble fragment represents a stable, antigen-recognizing variable domain, ideal for investigating T cell receptor biology and immune response mechanisms.

The T cell receptor alpha variable 21 (TRAV21) is a crucial component of the alpha-beta T cell receptor complex, which mediates antigen-specific immune responses. As part of the variable domain, TRAV21 directly participates in recognizing peptide-major histocompatibility (pMH) complexes displayed by antigen-presenting cells. This recognition initiates T cell activation through intracellular signaling cascades involving CD3 complex phosphorylation, ZAP70 recruitment, and downstream calcium, MAPK, and NF-kB pathways, ultimately driving T cell proliferation and differentiation. The receptor is membrane-bound and undergoes V-(D)-J rearrangement during thymic development to generate a d