Evidence for posttranslational control of fetal hemoglobin synthesis

Subunit competition experiments were conducted by recombining various amounts of alpha-subunits with an equimolar mixture of gamma- and beta A-subunits. The results showed that gamma-subunits combine with alpha-subunits less readily than beta A-subunits. Thus, in the presence of alpha-chain deficiency (alpha-thalassemia) the formation of HbA is preferred over HbF, resulting in a decrease in the level of the latter.