Immunochemistry of sperm-whale myoglobins prepared with various modified porphyrins and metalloporphyrins.

1. The preparation and characterization of manganese, iron, cobalt, nickel, copper and zinc metalloporphyrins is described. Ferrihaem was also esterified with pyrid-4-ylpropanol and the derivative characterized as the diester. 2. Complexes of these various porphyrins, as well as protoporphyrin IX, with apomyoglobin were formed and the resulting artificial myoglobins characterized. 3. Very little complex-formation was obtained with nickel, cobalt and manganese metalloporphyrins and apomyoglobin. 4. Myoglobin prepared with copper metalloporphyrin was immunochemically identical with native ferrimyoglobin. All the other artificial myoglobins were less reactive to varying degrees. 5. The changes in antigenic reactivities were attributed to conformational reorganization caused by the different co-ordination tendencies of the various metals or by the modification of the side chains of the haem.