A synthetic peptide capable of eliciting antibodies that neutralize human chorionic gonadotropin

• Published in: Fertility and sterility Vol. 36; no. 5; pp. 659 - 663
• Main Authors: Chang, Chin-Chuan, Tsong, Yun-Yen, Rone, Janice D., Segal, Sheldon J., Chang, Ding, Leban, Johann, Folkers, Karl
• Format: Journal Article
• Language: English
• Published: United States Elsevier Inc 01.11.1981
• Subjects: Amino Acid Sequence; Aminobutyrates; Animals; Antibody Specificity; Biological Assay; Chorionic Gonadotropin - immunology; Chorionic Gonadotropin - pharmacology; Cysteine; Epitopes; Female; Peptide Fragments - chemical synthesis; Peptide Fragments - immunology; Rabbits - immunology; Rats; Rats, Inbred Strains; Uterus - drug effects
• ISSN: 0015-0282; 1556-5653
• DOI: 10.1016/S0015-0282(16)45868-1

Antisera generated to the human chorionic gonadotropin β-subunit (hCGβ) 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 crossreactivity, a peptide fragment analogous to the amino acid sequence of the carboxyl-terminal 45 residues (101-145) of the hCGβ-subunit with α-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 hCGβ 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.