Immunoreactivities of peptides purified after cleavage of human liver apoferritin are reported and discussed in relation to the known 3-dimensional and primary structures of homologous apoferritins. These studies point to 3 antigenic sites occupying continuous inter-helical regions of the polypeptide chains which lie on the surface of the apoferritin molecule. Other antigenic regions may encompass amino acids remote in the primary structure or belonging to different subunits.
