KINETIC EVIDENCE FOR EXISTENCE OF ALPHA-GLOBIN POOL IN BETA-THALASSEMIC RETICULOCYTES

The kinetics of incorporation of 3H‐labeled amino acids into α, β, and γ globin has been determined, following incubation of intact reticulocytes, in stroma‐free hemolysates and in purified Hb F and Hb A from homozygous β‐thalassemic subjects. The labeled globins present in the cytoplasm as well as in purified Hb F and Hb A at various incubation times, were separated by CM‐cellulose chromatography, and the ratios of [3H]α to [3H]counterpart globins were determined. The results obtained show that in the initial stages of incubation, the ratios of [3H]α to [3H]‐counterpart globins are higher than 1 in the total lysate and in purified hemoglobins; these ratios, after long periods of incubation, decrease to values below 1. These findings suggest that the excess of newly synthesized α molecules flows very rapidly from the polyribosomes to the hemoglobins, and then, more slowly, to a “stromal”α pool. A model is presented, showing the most likely mechanism for the overall process. Copyright © 1968, Wiley Blackwell. All rights reserved