title: Antigenic features of human follicle stimulating hormone delineated by monoclonal antibodies and construction of an immunoradiomometric assay.
abstract: The characterization of human (h) FSH with 181 monoclonal antibodies (MCA) allowed the elucidation of its antigenic topography. One- and two-site, limited as well as excess reagent type radioimmuno- and enzymoimmunoassays revealed three main categories of MCA molecular binding specificities; two thirds of all antibodies were directed against the alpha-subunit and one fourth toward the beta-chain, and less than one tenth recognized the conformationally (c) intact holohormone. With high frequency immunization schedules these specificities were shifted toward a higher proportion of beta-MCA. On the basis of intra- and interspecies cross-reaction studies as well as epitope contiguity analyses by sandwich assays, the three main categories could be further subdivided into nine epitopes: 1) five epitopes associated with the alpha-subunit, two of which were suprisingly shared by other species, and two being iodination sensitive, 2) two evolutionary conserved structures on the beta-subunit, adjacent to each other, and 3) two c-determinants, one of these present also on hTSH. The epitopes were arranged in three major antigenic domains, which seems to be a common homologous construction principle of the four human glycoprotein hormones: a central domain, consisting of three identically arranged alpha- and similarly located c-epitopes, is flanked by a single spatially distinct domain on each subunit. The establishment of an epitope map was followed by the construction of an immunoradiometric assay with a sensitivity of 0.25 ng hFSH/ml and an apparent cross-reactivity vs. hLH, hTSH, and hCG of less than 1%.
authors: Immunoendocrinology Research Unit, Austrian Academy of Sciences, Innsbruck.
authors: P
authors: P
authors: Berger
authors: W
authors: W
authors: Panmoung
authors: D
authors: D
authors: Khaschabi
authors: B
authors: B
authors: Mayregger
authors: G
authors: G
authors: Wick
mesh_terms: D000818:Animals; D000911:Antibodies, Monoclonal / Q000276:immunology*; D000915:Antibody Affinity; D000918:Antibody Specificity; D000941:Antigens / Q000276:immunology*; D001667:Binding, Competitive; D004797:Enzyme-Linked Immunosorbent Assay; D000939:Epitopes / Q000276:immunology; D005260:Female; D005640:Follicle Stimulating Hormone / Q000276:immunology*; D006801:Humans; D006825:Hybridomas / Q000276:immunology; D007114:Immunization; D007118:Immunoassay; D007457:Iodine Radioisotopes; D051379:Mice; D008807:Mice, Inbred BALB C; D011863:Radioimmunoassay; D013045:Species Specificity
chemical_list: D000911:Antibodies, Monoclonal; D000941:Antigens; D000939:Epitopes; D007457:Iodine Radioisotopes; D005640:Follicle Stimulating Hormone