title: Site-specific antibodies to human erythropoietin directed toward the NH2-terminal region.
abstract: Site-specific antibodies to human erythropoietin have been raised in rabbits immunized with a synthetic polypeptide composed of the putative 26 NH2-terminal amino acids of the hormone. The immunogenic peptide was coupled to bovine serum albumin. Antibodies specific for peptide were detected by enzyme-linked immunosorbent assay. They immunoprecipitated both highly purified 125I-labeled erythropoietin and biologically active erythropoietin. The immunoprecipitation of 125I-labeled erythropoietin was inhibited by unlabeled erythropoietin and by peptide, demonstrating their crossreactivity. The antibodies did not neutralize erythropoietin's biological activity. These results indicate that a portion of the NH2-terminal region of erythropoietin is exposed on the surface of the protein at some distance from the receptor-binding domain. These antibodies will be important in further studies of the hormone and its mechanism of action.
mesh_terms: D000595:Amino Acid Sequence; D000740:Anemia / Q000652:urine; D000906:Antibodies; D000936:Antigen-Antibody Complex; D004797:Enzyme-Linked Immunosorbent Assay; D000939:Epitopes / Q000032:analysis*; D004921:Erythropoietin / Q000276:immunology* / Q000652:urine; D006801:Humans; D007074:Immunoglobulin G
chemical_list: D000906:Antibodies; D000936:Antigen-Antibody Complex; D000939:Epitopes; D007074:Immunoglobulin G; D004921:Erythropoietin