title: A synthetic peptide capable of eliciting antibodies that neutralize human chorionic gonadotropin.
abstract: Antisera generated to the human chorionic gonadotropin beta-subunit (hCGbeta) have been shown not only to neutralize the biologic activity of hCG but also to cross-react with human luteinizing hormone (hLH). In an attempt to reduce such cross-reactivity, a peptide fragment analogous to the amino acid sequence of the carboxylterminal 45 residues (101-145) of the hCGbeta-subunit with alpha-aminobutyric acid substituting for cysteine at position 110 was synthesized and tested for ability to produce antibodies interacting with hCG. Antisera were generated in rabbits to a conjugate of this peptide with tetanus toxoid emulsified with Freund's complete adjuvant. Antibody titers and specificity were assessed by the double-antibody technique. The results show that the antisera to the synthetic hCGbeta fragment bound 125I-labeled hCG and did not cross-react with hLH in the radioimmunoassay system. Most importantly, the antisera effectively neutralized the biologic activity of hCG as determined by the rat uterine weight assay.
mesh_terms: D000595:Amino Acid Sequence; D000613:Aminobutyrates; D000818:Animals; D000918:Antibody Specificity; D001681:Biological Assay; D006063:Chorionic Gonadotropin / Q000276:immunology* / Q000494:pharmacology; D003545:Cysteine; D000939:Epitopes; D005260:Female; D010446:Peptide Fragments / Q000138:chemical synthesis / Q000276:immunology*; D011817:Rabbits / Q000276:immunology; D051381:Rats; D011919:Rats, Inbred Strains; D014599:Uterus / Q000187:drug effects
chemical_list: D000613:Aminobutyrates; D006063:Chorionic Gonadotropin; D000939:Epitopes; D010446:Peptide Fragments; C012223:alpha-aminobutyric acid; D003545:Cysteine