title: Evidence for a gonadotropin from nonpregnant subjects that has physical, immunological, and biological similarities to human chorionic gonadotropin.
abstract: Substances from urinary extracts of normal, nonpregnant subjects and human pituitary gonadotropin preparations were found to react similarly to human chorionic gonadotropin (hCG) in a radioimmunoassay system that is highly specific for hCG and without crossreactivity to human luteinizing hormone (hLH). The antiserum was produced in a rabbit immunized with a bovine albumin conjugate of the unique carboxyl-terminal peptide (residues 123-145) isolated from a tryptic digest of the reduced, S-carboxymethylated hCGbeta subunit. The antibody recognition site on the peptide was found to reside on the last 15 amino acid residues of the carboxyl-terminal peptide, as evidenced by the competitive binding activities against 125I-labeled hCG of a series of peptides chemically synthesized according to the carboxyl-terminal sequence of HCGbeta. In order to elucidate the nature of the crossreacting substance in urinary extracts, a human postmenopausal urinary preparation (Pergonal) and a kaolin-acetone extract of urine from a patient with Klinefelter's syndrome were subjected to gel chromatography on Sephadex G-100. The results indicate that fractions showing immunocrossreactivity with the antiserum to hCGbeta-carboxyl-terminal peptide coeluted with 125I-labeled hCG which was separated distinctly from hLH. The same fractions from this postmenopausal urinary gonadotropin preparation exhibited in vitro biological activity proportional to the immunocrossreactivity of the hCG-specific antiserum. Concentration of postmenopausal women's urine by acetone precipitation retained approximately five times more immunoreactivity per unit volume than kaolin-acetone extraction, when assayed with the antiserum to hCGbeta-carboxyl-terminal peptide.
mesh_terms: D006063:Chorionic Gonadotropin / Q000032:analysis* / Q000276:immunology / Q000652:urine; D003429:Cross Reactions; D000939:Epitopes; D005260:Female; D006062:Gonadotropins / Q000032:analysis* / Q000276:immunology; D006801:Humans; D007713:Klinefelter Syndrome / Q000652:urine; D007986:Luteinizing Hormone / Q000276:immunology; D008297:Male; D008593:Menopause; D010455:Peptides / Q000276:immunology; D010902:Pituitary Gland / Q000032:analysis; D011863:Radioimmunoassay
chemical_list: D006063:Chorionic Gonadotropin; D000939:Epitopes; D006062:Gonadotropins; D010455:Peptides; D007986:Luteinizing Hormone