Excess of α‐Globin Synthesis in Homozygous β‐Thalassemia Its Cytoplasmic Molecular Forms

Abstract
The cytoplasmic distribution of the excess newly synthesized α‐globin, present in the red cell lysate of β‐thalassemic subjects has been investigated.The labelled globins present in the cytoplasm, as well as in purified Hb A and Hb F, were separated by CM‐cellulose chromatography, and the ratios 3Hα/3Hβ and 3Hα/3Hγ were determined.The results obtained show that an intracellular exchange occurs between non radioactive α‐chains of existing hemoglobins and the newly synthesized ones. Since the amount of labelled α‐globin chains which is found in combination with Hb A or Hb F does not account for all the newly synthesized α‐globin, it is concluded that part of this α‐globin must exist in a free form. A series of experimental data support the conclusion that this “free fraction” is probably composed of non heminated α‐globin molecules.