Study of human isoferritins from liver, spleen, heart and placenta by the microcomplement fixation technique.

Ferritin, iron storage protein, presents two types of subunits, H and L, the respective proportions of which varying with the tissue of origin and defining molecules called isoferritins. This work attempts to compare four human ferritins (from liver, spleen, heart and placenta) by means of the microcomplement fixation technique. Results show that placenta and liver ferritins are closely related, while slight but significant differences appear between liver, spleen and heart ferritins. These differences are obviously less important compared to those observed between ferritins from different species of origin, as shown by the results expressed in terms of index of dissimilarity or immunological distance. Those results are fully consistent with the elementary aminoacid composition as well as with the relative proportions of H and L subunits among the various types of human isoferritins we have studied.