Invitrogen™ HLA-A3 Monoclonal Antibody (GAP.A3), NovaFluor™ Blue 610-70S, eBioscience™, Invitrogen™

HLA-A3 is a subtype of the HLA class I heavy chain paralogues, existing in two forms: HLA-A3.1 and HLA-A3.2, which differ at amino acid positions 152 and 156. HLA class I molecules are heterodimers consisting of a heavy chain and a light chain (beta-2 microglobulin), with the heavy chain anchored in the membrane. These molecules are highly polymorphic cell surface glycoproteins expressed on nearly all nucleated cells. HLA class I molecules play a central role in the immune system by presenting intracellular peptides derived from the endoplasmic reticulum lumen on the cell surface. Non-native peptides are recognized by circulating cytotoxic T lymphocytes, facilitating immune surveillance. The heavy chain of HLA-A is approximately 45 kDa and its gene contains 8 exons. Exons 2 and 3 encode the alpha1 and alpha2 domains, which bind the peptide, while exon 4 encodes the alpha3 domain, exon 5 encodes the transmembrane region, and exons 6 and 7 encode the cytoplasmic tail. Polymorphisms within exons 2 and 3 determine the peptide binding specificity of each class I molecule, and typing for these polymorphisms is routinely performed for bone marrow and kidney transplantation. Hundreds of HLA-A alleles have been described, and HLA and MHC antibodies are crucial in immunopeptidomics, aiding in the identification and characterization of neoantigens through techniques such as high-performance liquid chromatography coupled to tandem mass spectrometry.