title: beta 2-Microglobulin and its relationship to the immune system.
abstract: beta 2-Microglobulin has been isolated from several species, but only bovine beta 2-microglobulin, previously known as lactollin, has been crystallized. An improved method for its isolation from colostrum is described. The bovine homologue exhibits a concentration-dependent aggregation behavior. beta 2-Microglobulin is related to both immune and histocompatibility antigen systems. It exhibits homology with the constant domains of the immunoglobulin-G light and heavy chains and is an integral part of histocompatibility antigens bound to cell surface. beta 2-Microglobulin also occurs in the free state in various body fluids including milk and colostrum. The possible relationship of elevated free beta 2-microglobulin of pathological conditions is suggested for future research.
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001609:Beta-Globulins / Q000276:immunology*; D002417:Cattle; D003126:Colostrum / Q000276:immunology; D006680:HLA Antigens / Q000032:analysis; D006649:Histocompatibility Antigens / Q000032:analysis; D006801:Humans; D008892:Milk / Q000276:immunology; D001613:beta 2-Microglobulin / Q000032:analysis / Q000096:biosynthesis / Q000276:immunology*
chemical_list: D001609:Beta-Globulins; D006680:HLA Antigens; D006649:Histocompatibility Antigens; D001613:beta 2-Microglobulin