The antigenic structure of the human glycoprotein hormone alpha-subunit: II. Cross-species comparisons.
Eight monoclonal antibodies, specific for the glycoprotein hormone alpha-subunit, were raised against human free alpha-subunit, human FSH, or human CG. All of these antihuman monoclonal antibodies were tested for cross-reactivity with alpha-subunits derived from bovine, porcine, equine, bull frog, sea turtle, turkey, and ostrich glycoprotein hormones. All showed cross-reactivity with affinities ranging from 10(-4) to 10(-8) depending upon the antibody and the species of alpha-subunit. Cyanogen bromide fragments of bovine and equine alpha, when tested with selected antibodies indicated that antigenic determinants could be localized in two regions: alpha 9-33 and alpha 76-92. Comparison of amino acid sequences, and relative potencies, suggest that major antigenic determinants involve residues 21, 22, and 23 (F-F-S in human alpha) and 76-85 (G-G-F-K-V-E-N-H-T-A in human alpha). As part of this study the N-terminal amino acid sequences of bull frog, sea turtle, turkey, and ostrich alpha-subunits were determined and reported for the first time.
Bergert
E R
ER
Department of Biochemistry and Molecular Biology, Mayo Medical School, Rochester, Minnesota 55905.
Madden
B
B
McCormick
D J
DJ
Papkoff
H
H
Ryan
R J
RJ
D000595:Amino Acid Sequence; D000818:Animals; D000911:Antibodies, Monoclonal / Q000276:immunology*; D003429:Cross Reactions; D000939:Epitopes / Q000032:analysis*; D015292:Glycoprotein Hormones, alpha Subunit / Q000032:analysis / Q000235:genetics / Q000276:immunology*; D006801:Humans; D008969:Molecular Sequence Data; D011863:Radioimmunoassay; D012689:Sequence Homology, Nucleic Acid; D013045:Species Specificity
D000911:Antibodies, Monoclonal; D000939:Epitopes; D015292:Glycoprotein Hormones, alpha Subunit