Production and characterization of antibodies to thymosin beta sub(4)

Thymosin beta sub(4) antibodies have been raised in rabbits by conjugating the peptide to keyhole limpet hemocyanin, and a radioimmunoassay for thymosin beta sub(4) has been established utilizing tritiated thymosin beta sub(4) as binding ligand. RIA values for thymosin beta sub(4) in rat tissues reveal levels raning between 8 and 448 mu g/g wet weight. Highest levels are observed in spleen, although the peptide is also ralatively abundant in thymus, lung, and nasal epithelium. The specificity of the antiserum used in the RIA has been defined. The thymosin beta sub(4) molecule seemingly bears two major epitopes that lie between amino acid residues 1-8 and 22-32. The antiserum does not cross-react with other unrelated peptides. The antiserum will precipitate biosynthetically labeled beta sub(4) from cultured rat peritoneal macrophage.