title: Cross-reactivity of antibodies against synthetic peptides.
abstract: Antiserum against the synthetic peptide Lys-Arg-Ser-Arg-His-Phe, corresponding to the carboxy terminus of polyoma virus medium tumor antigen (medium T antigen), immunoprecipitates a protein of 36,000 daltons from polyoma virus-infected and uninfected cell extracts treated with the sulfhydryl group reagent N-ethyl-maleimide. This protein appears to share an antigenic determinant with medium T antigen that is normally buried inside the protein or covered up by another protein or cellular structure. The two-dimensional tryptic fingerprints of the 36K protein and of medium T antigen are apparently unrelated to each other. Antiserum against the octapeptide Ac-Met-Asp-Lys-Val-Leu-Asn-Arg-Tyr, including the amino-terminal heptapeptide sequence of the simian virus 40 (SV40) large tumor (T) and small T antigens, cross-reacts with polyoma virus large T antigen, which has an identical amino-terminal heptapeptide sequence except that Lys is replaced by Arg and Asn by Ser. The problem of cross-reactivities of antipeptide sera is discussed.
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D000906:Antibodies / Q000276:immunology*; D000951:Antigens, Neoplasm / Q000276:immunology; D002478:Cells, Cultured; D003429:Cross Reactions; D007158:Immunologic Techniques; D051379:Mice; D010455:Peptides / Q000276:immunology*; D011120:Polyomavirus / Q000276:immunology; D011506:Proteins / Q000276:immunology; D013539:Simian virus 40 / Q000276:immunology
chemical_list: D000906:Antibodies; D000951:Antigens, Neoplasm; D010455:Peptides; D011506:Proteins