title: Further structural studies of the heavy chain of HLA antigens and its similarity to immunoglobulins.
abstract: The papain-solubilized fragment of the heavy chain of HLA-B7, which is the NH2-terminal part of the whole polypeptide chain, can be divided into three regions by mild acid and cyanogen bromide cleavages. The first 100 amino acids terminating in a methionine residue contain the carbohydrate moiety; this segment is followed by two others of molecular weights 9,999 and 13,000, each containing an intrachain disulfide bridge. The two intrachain disulfide bridges are separated by a stretch of amino acids containing an acid-labile aspartyl-prolHLA-2, A28, and AW25 contain this acid-labile peptide bond in their larger subunit. Sequencing from the acid cleavage site of HLA-7 through the third half-cystine revealed consideralbe homology with amino acid sequences around a half-cystine in immunoglobulin variable regions.
mesh_terms: D000595:Amino Acid Sequence; D002460:Cell Line; D002462:Cell Membrane / Q000032:analysis; D004220:Disulfides / Q000032:analysis; D006680:HLA Antigens / Q000302:isolation & purification; D007143:Immunoglobulin Heavy Chains / Q000302:isolation & purification; D046911:Macromolecular Substances; D008970:Molecular Weight; D010446:Peptide Fragments / Q000032:analysis
chemical_list: D004220:Disulfides; D006680:HLA Antigens; D007143:Immunoglobulin Heavy Chains; D046911:Macromolecular Substances; D010446:Peptide Fragments