A pool of native alpha-chains in guinea pig reticulocytes

Five radioactive peaks can be identified when hemolysates prepared from ⁵⁹Fe-labelled guinea pig reticlocytes are subjected to molecular sieve chromatography. The third peak, hemoglobin, is followed by another hemi-containing peak eluting with an apparent molecular weight of 17,000. We now demonstrate that this 17,000 MW peak consists of α-chains. The high specific activity (⁵⁹Fe/heme) of these α-chains suggests that they may be the primary site of heme entry into the hemoglobin molecule.