Mouse Anti-Mouse MHC Class I (H-2Db) Antibody (S-5513)

MHC Class I (H-2Db) is a classical major histocompatibility complex class I molecule of the mouse H-2ᵇ haplotype, serving as the murine homolog of human HLA-A/B/C antigens. Like all MHC class I molecules, H-2Db is a heterodimer composed of a polymorphic transmembrane α heavy chain non-covalently associated with the invariant light chain β2-microglobulin; the α chain contains three extracellular domains (α1, α2, and α3), with α1 and α2 together folding to form the peptide-binding groove, while α3 adopts an immunoglobulin fold. H-2Db is expressed on the surface of nearly all nucleated cells and presents endogenous peptide antigens—typically 8–10 amino acids in length—to CD8⁺ cytotoxic T lymphocytes, thereby enabling immune surveillance of infected and transformed cells. A distinctive structural feature of H-2Db is a mouse-specific hydrophobic ridge in the peptide-binding cleft that forces a compensatory arch in the peptide backbone, exposing arch residues to T-cell receptor contact and requiring a minimum peptide length of nine residues; this ridge is shared by approximately 40% of known murine D and L allelic molecules, defining a structural subgroup. Functionally, H-2Db is central to antigen presentation in the H-2ᵇ mouse strains (such as C57BL/6), and its presentation of peptides derived from both intracellular and cross-presented exogenous antigens is essential for antitumor and antiviral immunity.