title: beta 2-Microglobulin and transplantation antigens.
abstract: The complete amino acid sequence of papain-solubilized HLA A, B and C antigens representing the cell surface-expressed portion of the transplantation antigens has been elucidated. The HLA antigen heavy chains seem to be composed of three domains, one of which binds beta 2-microglobulin. The HLA antigen heavy chain domain closest to the membrane displays striking amino acid homology with immunoglobulin light and heavy chains and with beta 2-microglobulin. The other two domains, which show no statistically significant homology with immunoglobulins, are related to each other. This suggest that the HLA antigen heavy chains have arisen by a series of gene duplication events.
mesh_terms: D000595:Amino Acid Sequence; D001609:Beta-Globulins / Q000276:immunology*; D005075:Biological Evolution; D005796:Genes; D006680:HLA Antigens / Q000235:genetics; D007136:Immunoglobulins / Q000235:genetics; D046911:Macromolecular Substances; D001613:beta 2-Microglobulin / Q000276:immunology*
chemical_list: D001609:Beta-Globulins; D006680:HLA Antigens; D007136:Immunoglobulins; D046911:Macromolecular Substances; D001613:beta 2-Microglobulin