title: The antigenic determinant of the LH-releasing hormone for three different antisera.
abstract: Antigenic determinants of LH-releasing hormone (LH-RH) were investigated by testing the cross-reaction of LH-RH analogues and fragments in LH-RH radioimmunoassay (RIA) systems using 3 different antisera against the LH-RH decapeptide. Rabbit antiserum No. 419 was generated against LH-RH adsorbed on polyvinylpyrrolidone (PVP). Antisera Nos. 710 and 742 were produced by immunizing rabbits with LH-RH conjugated either with bovine serum albumin through its C-terminus, or with human serum albumin through the N-terminus, respectively. For antiserum No. 419, the N-terminal (pyro)-glutamic acid and/or histidine in positions 1 and 2 of LH-RH, respectively, were found to enhance the antigen-antibody interaction, but were not indispensable for it. Similarly, the C-terminal amide and glycine-NH2 did not play a major role in these interactions. The LH-RH heptapeptide fragment, corresponding to amino acid sequence from positions 3 to 9, showed a cross-reactivity in this RIA system with LH-RH, although greater amounts than those of cold LH-RH were required for a comparable inhibition of binding of labelled LH-RH. For antiserum No. 710, the LH-RH hexapeptide fragment corresponding to positions 2 to 7 showed considerable cross-reactivity. Histidine in position 2 played an important role but neither the amide group nor the glycine amide group at the C-terminus were essential. For antiserum No. 742, the C-terminal tetrapeptide-amide fragment of LH-RH showed considerable cross-reactivity in the LH-RH, the amide moiety itself being of crucial importance. These antisera may be useful in investigating peptides related to LH-RH in biological materials.
mesh_terms: D000577:Amides; D000595:Amino Acid Sequence; D000818:Animals; D000937:Antigen-Antibody Reactions; D002352:Carrier Proteins / Q000276:immunology; D003429:Cross Reactions; D000939:Epitopes; D005971:Glutamates; D005998:Glycine; D007987:Gonadotropin-Releasing Hormone / Q000031:analogs & derivatives / Q000276:immunology*; D006639:Histidine; D007106:Immune Sera; D010446:Peptide Fragments; D011205:Povidone / Q000276:immunology; D011817:Rabbits / Q000276:immunology; D011863:Radioimmunoassay; D012709:Serum Albumin / Q000276:immunology; D012710:Serum Albumin, Bovine / Q000276:immunology
chemical_list: D000577:Amides; D002352:Carrier Proteins; D000939:Epitopes; D005971:Glutamates; D007106:Immune Sera; D010446:Peptide Fragments; D012709:Serum Albumin; D012710:Serum Albumin, Bovine; D007987:Gonadotropin-Releasing Hormone; D006639:Histidine; D011205:Povidone; D005998:Glycine